Top Klaviyo development companies (July 2026 Update)

Most ecommerce businesses that struggle with Klaviyo are not struggling with the interface. Klaviyo's flows builder, segment editor, and campaign dashboard are genuinely good. The struggle is upstream: the data is not arriving. A product catalog that stopped syncing three weeks ago. A custom event that never fires when the backend processes a subscription renewal. A CDP that holds the behavioral signals but has never been wired to Klaviyo's custom properties. A webhook from a third-party loyalty platform that drops silently on high-volume days. When the data layer is broken, every flow in Klaviyo is working beautifully on stale or incomplete information -- and the interface gives no warning.

The second thing buyers miss is that "Klaviyo company" covers two very different problems. The first is technical: building the integrations, event schemas, custom property pipelines, CDP feeds, and webhook architectures that make Klaviyo's data accurate and complete. That is engineering work, not marketing work. The second is strategic and executional: building the flows, segments, campaigns, and lifecycle programs that turn that data into revenue. The best Klaviyo outcomes require both, but most buyers shop for one and discover they needed the other six months in, after the agency retainer has been burning for three months on a data layer full of gaps.

Klaviyo serves over 167,000 businesses globally and sends approximately 3.8 billion emails per month (Klaviyo FY 2024 Results). Email marketing generates an average ROI of $36 for every $1 spent (Litmus). Those numbers explain why the platform is crowded with agencies and why buyers are confused about who does what. But ROI that high is built on flows that fire when they should, segments that update when behavior happens, and events that capture what the customer actually did -- not a sampling of what happened on the main ecommerce platform while a third of the customer activity went untracked in a custom backend.

It helps to name the Klaviyo stack clearly. Flows handle automated sequences triggered by behavior: abandoned cart, post-purchase, browse abandonment, win-back. Campaigns handle one-time sends: promotions, announcements, newsletters. Segmentation drives both, pulling on profile properties, event history, predictive analytics, and purchase behavior. Klaviyo Forms capture new profiles. The Klaviyo CDP consolidates identity across channels. And Klaviyo's API -- the Track API, Identify API, and Catalog API -- is the door through which custom events, product feeds from non-standard backends, and behavioral signals from third-party tools enter the platform. A company's Klaviyo results are bounded by how complete and accurate the data feeding those systems actually is.

This is a buyer's guide to the companies you hire to build on Klaviyo -- technical integration partners and managed-service lifecycle agencies -- not a list of Klaviyo alternatives. The eight Klaviyo development companies on this list are SmartBug Media, Chronos Agency, RaftLabs, Flowium, Groove Commerce, Hawke Media, Common Thread Collective, and Electric Eye. RaftLabs is on this list. We wrote our own entry with the same directness we applied to everyone else.

How we evaluated this list

No company paid for placement on this list.

1. SmartBug Media

SmartBug Media is a full-service inbound marketing agency with Klaviyo Master Elite status -- the highest tier Klaviyo awards, held by fewer than a handful of agencies worldwide. Founded in 2007 and headquartered in Newport Beach, California, it has built one of the strongest Klaviyo practices in the US market, managing email and SMS programs for ecommerce brands across DTC, retail, and subscription models. It is also a Google Premier Partner and a Shopify partner, giving it a cross-platform reach that extends well beyond email.

Among Klaviyo agencies, SmartBug sits at the top of the managed-service tier. If the problem is campaign performance -- open rates, click-through rates, flow attribution, list growth, A/B testing at scale -- and the brand wants a partner to own the channel end to end, SmartBug has the team depth, platform access, and Master Elite support from Klaviyo to do it. Master Elite agencies receive priority access to Klaviyo's product team, beta features, and dedicated technical support -- which matters when a deliverability problem needs escalation or a new Klaviyo feature needs early access.

The HubSpot crossover is worth understanding separately. Many brands run Klaviyo for retention marketing and HubSpot for sales CRM and partner management. SmartBug holds deep certifications on both, which means its Klaviyo work can be coordinated with lead and deal data from HubSpot without a separate integration vendor managing the seam. For a brand that runs both platforms and has felt the gap between its email retention program and its sales pipeline, that dual expertise is a material advantage that most Klaviyo-only agencies cannot replicate.

SmartBug brought over 200 new businesses to Klaviyo's platform since joining the partner program, and its Master Elite designation reflects the volume of accounts managed, the revenue generated through the platform, and the technical certification depth across its team. Those are the metrics Klaviyo uses to award its highest tier, and they matter because they predict the quality of an agency's Klaviyo knowledge, not just its sales.

Notable work -- SmartBug has published case studies across DTC, subscription ecommerce, and B2B technology, with documented improvements in email-attributed revenue, open rates, and lifecycle program performance. Its portfolio spans multiple industries and is anchored by brands that wanted a long-term retained partner for email and lifecycle, not a one-time setup.

Pricing signal -- SmartBug operates as a retained managed-service agency. Retainer engagements typically start in the $5,000 to $15,000 per month range depending on account size, complexity, and the number of active flows and campaigns. One-time setup or migration engagements are structured separately. Its rates reflect the Master Elite overhead: deeper platform access, faster escalation, and a team that has managed the platform at volume.

What to watch -- SmartBug is a managed-service agency, not a development firm. If the problem is a broken integration, a custom event schema that never fires from a proprietary backend, or a CDP that has never been wired to Klaviyo's custom properties, that is engineering work that falls outside the managed-service scope. Confirm the division of labor during scoping if your Klaviyo data layer has technical gaps before the retainer begins.

• Best for: Ecommerce and subscription brands that want a retained partner to own the Klaviyo channel end to end, with HubSpot crossover depth

• Specialization: Full lifecycle management, Klaviyo + HubSpot programs, DTC and subscription ecommerce, deliverability

• Pricing: Retainer-based, typically $5,000-$15,000/month

• Clutch: Verify on Clutch before engaging

2. Chronos Agency

Chronos Agency is a lifecycle marketing agency and Klaviyo Master Elite partner, founded in 2017 and headquartered in Singapore with teams across Asia-Pacific. It has managed Klaviyo accounts generating over $400 million in email-attributable revenue across 500-plus ecommerce brands, with a focus on building retention systems that maximize customer lifetime value across the full acquisition-to-loyalty arc. Its channel stack covers email, SMS, and push, and its segmentation infrastructure ties them together into coordinated lifecycle programs rather than isolated channel sends.

Chronos earns its place near the top of this list because its focus is LTV, not sends. The difference is what gets built and measured. A sends-focused agency optimizes for open rates and list growth. An LTV-focused agency optimizes for repeat purchase rate, time between orders, average order value across the customer lifecycle, and churn risk scored before it becomes visible in revenue. Those are different programs, and building them requires a different segmentation depth: predictive analytics from Klaviyo's built-in models, behavioral cohort analysis, RFM scoring, and suppression logic that keeps deliverability clean across a large list under high send volume. Chronos has built those programs at scale across categories including fashion, beauty, health, and consumer goods.

The depth across 500-plus brands also means Chronos has encountered most of the failure modes that agencies discover slowly and expensively. The campaign that tanks deliverability on Yahoo after a list clean was skipped. The flow sequence that fires out of order when a Recharge event arrives with a delay relative to the Shopify order event. The SMS program that drives unsubscribes because the timing window is wrong for the audience's time zone distribution. The win-back sequence that re-engages lapsed buyers at the wrong discount depth and trains margin expectations downward. A firm that has run into these failure modes and fixed them is faster and less expensive to work with than one that has not, because the learning costs money.

For brands in the $1M to $20M revenue range that want to professionalize the Klaviyo channel without building an in-house email team, Chronos offers one of the clearest alternatives: it can handle strategy, creative, copywriting, platform configuration, and ongoing optimization without the brand coordinating multiple vendors.

Notable work -- Chronos has published case studies documenting revenue improvements across DTC brands, with its track record centered on lifecycle programs generating consistent, compounding email-attributed revenue. Client names are largely kept confidential in published materials, though references are available during scoping. The $400M-plus figure in email-attributable revenue across its client base is documented on its website and in its Klaviyo partner listing.

Pricing signal -- Chronos operates on a retainer model. Entry points typically start around $3,000 to $8,000 per month depending on list size, channel scope (email only versus email plus SMS plus push), and the complexity of flows and segmentation required. Large-account retainers covering full channel management run higher.

What to watch -- Chronos is strongest on lifecycle marketing execution. For brands that need deep technical work at Klaviyo's API layer -- custom event schemas from a proprietary backend, product catalog syncs outside Shopify and WooCommerce, or CDP identity consolidation -- the managed-service model has limits. Engineering work should be scoped and completed before the marketing engagement begins.

• Best for: DTC brands wanting a full lifecycle marketing partner with deep Klaviyo execution experience and an LTV-first retention framework

• Specialization: Email, SMS, push, lifecycle programs, LTV optimization, DTC ecommerce across fashion, beauty, and consumer goods

• Pricing: Retainer-based, typically $3,000-$8,000/month starting

• Clutch: Verify on Clutch before engaging

3. RaftLabs

RaftLabs is a product development and growth marketing engineering firm, founded in 2015, that builds the technical integrations Klaviyo depends on: custom event schemas piped from proprietary ecommerce backends, product catalog syncs from platforms that Klaviyo's native connectors do not reach, CDP integrations that consolidate identity and behavioral data into Klaviyo's custom properties, and webhook-driven behavioral triggers that fire Klaviyo flows from third-party systems -- loyalty platforms, subscription billing tools, custom ERPs, and support systems that sit outside the standard Shopify stack. It sits at number three on this list because the companies above it are excellent managed-service agencies, and a managed-service agency's results are bounded by the quality of the data layer underneath them. RaftLabs builds that layer.

The distinction is often invisible until it fails. A Klaviyo account with a clean integration fires events accurately, syncs the catalog in real time, sends the right profile properties to segmentation, and triggers flows at the moment the relevant behavior happens. A Klaviyo account on a broken integration fires events late or partially, syncs catalog data on a 24-hour delay, sends incomplete profile properties that leave segments under-populated, and triggers flows on stale data that creates the wrong message at the wrong moment. The Klaviyo interface looks identical in both cases. The revenue difference is large.

RaftLabs has shipped software for clients including Vodafone, T-Mobile, Cisco, and Wyndham Hotels. The same data integration and event-pipeline discipline that carries through telecom billing systems and hospitality loyalty programs carries directly into the Klaviyo layer for ecommerce brands on custom backends.

Its Klaviyo-adjacent work covers the three integration problems that block the most ecommerce brands from getting accurate data into the platform. The first is custom event tracking: when a brand runs a custom-built ecommerce platform, a headless commerce architecture, or a subscription billing system that Klaviyo's native connectors do not support, custom events must be piped through Klaviyo's Track API with the right property schema. RaftLabs builds the event schemas, the server-side tracking layer, and the validation pipeline that keeps events reliable under load. The second is product catalog sync: Klaviyo's native catalog block works well for Shopify and WooCommerce. For custom backends or custom product data structures, the catalog feed must be built, normalized, and kept current through Klaviyo's Catalog API. The third is CDP and identity consolidation: when a brand's customer data is split across an ecommerce platform, a CRM, a loyalty system, and a support tool, Klaviyo's CDP needs a clean identity merge layer. RaftLabs builds that merge layer, resolving the same customer across multiple first-party systems so segmentation runs on a complete profile.

Its 4.9/5 rating on Clutch across 50+ verified reviews reflects a model where one team covers the backend engineering, the API integration, and the platform configuration -- no handoff gap between a development team and a separate marketing operations team, no vendor-blaming when an event fires incorrectly.

Notable work -- RaftLabs has shipped data pipelines, product integrations, and custom tracking for clients across ecommerce, telecom, and hospitality. Its growth marketing and MarTech integration work includes the same event-schema design, API integration, and data-pipeline discipline that a Klaviyo integration at depth requires. Its product portfolio is documented on its website.

Pricing signal -- RaftLabs operates at $29-$49/hr for most engagements, with fixed-price structures available for well-defined integration scopes. A Klaviyo integration project covering custom event tracking, catalog sync, and CDP wiring typically starts in the mid five figures and scales with the number of systems involved. The model is priced for owned delivery, not rented capacity.

What to watch -- RaftLabs is an integration and development firm, not a lifecycle marketing agency. It builds the data layer and the technical integrations. Running email campaigns, managing flows, and doing ongoing creative execution is a separate scope. Brands that need both technical integration and managed campaign execution should scope the two separately: RaftLabs for the engineering, a lifecycle agency for the ongoing marketing.

• Best for: Ecommerce brands on custom or non-standard backends that need Klaviyo's data layer engineered and maintained by one accountable team

• Specialization: Custom event tracking, product catalog syncs, CDP integration, webhook-driven triggers, MarTech backend engineering

• Pricing: $29-$49/hr, fixed-price engagements available

• Clutch: 4.9/5 (50+ verified reviews)

4. Flowium

Flowium is a full-service email and lifecycle marketing agency and Klaviyo Master Elite partner, founded by Andriy Boychuk in 2017. It has served over 1,000 brands including True Classic and Dr. Squatch, with a team of 40-plus specialists and a documented 97% client success rate. Its focus is retention marketing: building the email and SMS programs that turn first-time buyers into repeat customers and lapsed customers back into the purchase cycle. Its channel stack extends beyond email and SMS to WhatsApp, push, and Instagram DM, all coordinated from Klaviyo as the platform of record.

Flowium's strength is retention architecture at a level of detail most agencies stop short of. The standard Klaviyo setup -- welcome series, abandoned cart, post-purchase, win-back -- gets most brands to their first meaningful email-attributed revenue contribution. The next level requires deeper segmentation: predictive churn scoring, RFM cohort programs, VIP tier management, browse-abandonment sequences tuned to product category rather than the generic version, and suppression logic that keeps deliverability clean as the list grows past 200,000 contacts. Flowium builds those programs, not just the standard flows.

The multi-channel coordination matters in a specific way. For most ecommerce brands, email is the anchor channel and SMS is the urgency layer. A promotional deadline lives in SMS because it drives response within minutes. A storytelling campaign lives in email because it needs room. A win-back sequence benefits from both because lapsed buyers respond differently across channels and at different times of day. Flowium coordinates these channels from Klaviyo's sequence engine rather than running them as parallel programs, which means the messaging is deduplicated, the timing is managed, and a buyer who converts through the SMS path is removed from the parallel email flow -- preventing the double-attribution problem that inflates email revenue numbers at brands where the channels are siloed.

Its Master Elite status reflects the volume of accounts managed, the platform revenue generated, and the technical certification depth across the team. At the entry point for a brand doing $1M to $10M in annual revenue that wants to stop managing email in-house, Flowium offers a clear and well-documented alternative.

Notable work -- Flowium has published case studies and an extensive email marketing resource library, with documented performance improvements across DTC brands in fashion, home goods, and consumer goods. Named clients include True Classic and Dr. Squatch. Its track record is anchored by retention programs that generate consistent, compounding email-attributed revenue rather than one-time campaign peaks.

Pricing signal -- Flowium operates on a retainer model. Entry-level retainers typically start around $3,000 to $5,000 per month for email-only programs. Full-channel retainers covering email, SMS, and additional channels run higher depending on list size and campaign volume.

What to watch -- Flowium is a lifecycle marketing agency, not a development firm. If a brand's Klaviyo integration has technical gaps -- events not firing from a custom backend, a product catalog not syncing from a non-standard platform, a CDP that has never been wired -- those problems need an engineering partner before the managed-service engagement can perform. Confirm the state of the integration before the retainer begins.

• Best for: DTC brands wanting retention-focused lifecycle marketing with multi-channel coordination across email, SMS, and push

• Specialization: Email, SMS, push, lifecycle retention programs, DTC ecommerce, predictive segmentation

• Pricing: Retainer-based, typically $3,000-$5,000/month starting

• Clutch: Verify on Clutch before engaging

5. Groove Commerce

Groove Commerce is a multi-platform ecommerce agency and Klaviyo Elite partner, specializing in ecommerce development across Shopify Plus, BigCommerce, and Magento alongside its Klaviyo implementation and email marketing practice. Founded in 2007 and headquartered in Baltimore, it has built a dual-track practice: ecommerce platform development on one side and email lifecycle marketing through Klaviyo on the other. For brands that need both the ecommerce platform and the retention channel built in one engagement, that combination is a meaningful advantage.

The combination matters in a specific, structural way. When an agency builds the Shopify Plus store and the Klaviyo integration in the same engagement, the event schema gets designed with both systems in mind. Checkout events, product view events, and order events are structured to carry the right properties from the moment the platform goes live, rather than being retrofitted later when someone notices the segmentation is broken. The product catalog syncs from day one because the team that built the product database also built the catalog feed to Klaviyo. That alignment between platform and Klaviyo is the advantage Groove Commerce's dual-track practice offers -- and it is something a standalone lifecycle agency and a standalone ecommerce developer cannot replicate without close coordination that is difficult to manage across separate vendor relationships.

Its Elite partner status and long track record in ecommerce development mean it has handled the standard Klaviyo integration patterns at depth: Shopify order data flowing into post-purchase sequences, cart events driving abandoned cart flows, product recommendations powered by catalog data, and list growth through Klaviyo Forms integrated with the ecommerce checkout. For brands on supported platforms, Groove Commerce is a strong full-build partner that removes the seam between the platform and the email program.

Notable work -- Groove Commerce has published case studies documenting ecommerce platform builds and Klaviyo implementation outcomes. Its portfolio spans DTC and B2C retail brands across Shopify Plus, BigCommerce, and Magento. Specific client names are available on its website.

Pricing signal -- Groove Commerce works on a project and retainer basis. Platform development projects typically start in the $30,000 to $80,000 range depending on platform, custom functionality, and migration complexity. Klaviyo-specific managed service retainers start lower and scale with account size. The dual-track model means project and retainer costs stack for brands that need both delivered together.

What to watch -- Groove Commerce is strongest on supported ecommerce platforms. For brands on custom backends, headless architectures outside the standard Shopify/BigCommerce/Magento stack, or proprietary systems, the native integration depth drops and custom API-level work falls into a different scope. Confirm platform compatibility and what the integration scope covers during the discovery phase.

• Best for: Brands building on Shopify Plus, BigCommerce, or Magento that want the ecommerce platform and the Klaviyo retention channel built in one engagement

• Specialization: Ecommerce platform development, Klaviyo implementation, email marketing, lifecycle programs

• Pricing: Platform projects from $30,000; retainer-based for managed services

• Clutch: Verify on Clutch before engaging

6. Hawke Media

Hawke Media is a full-service digital marketing consultancy and Klaviyo Platinum Master partner, founded in 2014 and headquartered in Los Angeles. It has brought over 200 brands to the Klaviyo platform since joining the partner program, and its lifecycle marketing team carries product certifications across Klaviyo's platform. Its model is the full-service approach: Klaviyo email and SMS programs run alongside paid advertising, social media, content, and SEO, all coordinated by CMO-level strategy. For brands that want their email retention program to talk to their paid acquisition -- not run as a separate island -- that coordination is the draw.

The coordination between email and paid channels is real and generates specific results when it is done well. Klaviyo segments make high-quality audiences for paid retargeting: a lapsed-buyer segment exported to Facebook or Google is a high-intent audience for retargeting at a lower cost than cold acquisition. A brand-new buyer segment suppressed from paid acquisition reduces wasted spend on customers who already converted. A promotional email landing page tied to a specific paid campaign should trigger the right Klaviyo welcome flow, not the generic one. When the same agency runs both channels, those connections are designed in at the start. When two separate agencies run them, the connections happen late or not at all, and neither team has full visibility into the other's timing.

Hawke Media's breadth is also its trade-off. As a full-service agency, it spreads attention across many channels. Brands whose primary need is Klaviyo depth -- a segmentation program that hits the second and third standard deviation of behavioral precision, deliverability management at large list scale, or complex flow architecture for a sophisticated retention model -- will find the Master Elite specialists higher on this list more focused on that specific depth. Hawke is the right choice when the brand's email program is one part of a larger, coordinated agency relationship rather than the whole game.

Notable work -- Hawke Media has published client case studies across many verticals, with documented results in paid media, email, and content. Its Klaviyo practice is evidenced by the Platinum Master designation and the depth of its lifecycle marketing team's certifications. It has served brands across DTC, retail, and B2C at various revenue scales.

Pricing signal -- Hawke Media operates on a retainer model with modular service selection. Email and lifecycle retainers through Klaviyo start in the $2,000 to $5,000 per month range as a standalone service. Full-service retainers covering multiple channels run higher, scaling with the number of active channels and account complexity.

What to watch -- Hawke Media is a full-service agency first. Its depth is distributed across channels rather than concentrated in Klaviyo. For brands whose primary need is deep Klaviyo specialization -- complex lifecycle programs, advanced segmentation, or deliverability management at large scale -- a specialist agency will outperform the generalist model.

• Best for: Brands that want Klaviyo email running as part of a broader, coordinated full-service digital marketing engagement with paid and social

• Specialization: Full-service digital marketing, Klaviyo email and SMS, paid media, social, DTC and retail

• Pricing: Retainer-based; Klaviyo module from $2,000-$5,000/month

• Clutch: Verify on Clutch before engaging

7. Common Thread Collective

Common Thread Collective is a performance growth agency and Klaviyo partner focused on DTC brands between $10M and $100M in annual online revenue. Founded in 2012 and headquartered in Los Angeles -- and recently backed by The Acacia Group -- it runs a full-funnel growth model: paid media, content production, web development, branding, influencer marketing, and email all coordinated through a single growth framework centered on profitable growth rather than revenue growth alone. Its email work through Klaviyo is embedded in a wider acquisition and retention strategy, not managed as a standalone channel.

This full-funnel framing works at a specific brand stage and under a specific business philosophy. At $10M to $30M in DTC revenue, email retention and paid acquisition are not separate programs -- they are the same customer moving through different moments of the same funnel. A brand whose Facebook campaigns are bringing in cold traffic needs its welcome flow to match the ad creative. Its abandoned cart sequence should carry the product-specific social proof from the landing page rather than generic urgency copy. Its post-purchase series should be timed and toned to set up the second purchase, not simply confirm the first one. When the same team runs acquisition and retention, those connections are designed in from the start. Common Thread Collective's framework centers on contribution margin and repeat purchase rate as the primary signals -- which suits founders who are tired of high-topline, low-margin growth and want retention metrics that connect to actual profit rather than email-attributed revenue inflated by last-click models.

The institutional backing from The Acacia Group in 2025 signals a growth trajectory and the resources to maintain the team depth that the full-funnel model requires. For brands that want their email program inside a long-term growth relationship with a firm that thinks about the full funnel, Common Thread Collective is on the shortlist.

Notable work -- Common Thread Collective has published an extensive library of DTC growth content, frameworks, case studies, and a well-followed podcast. Named clients span consumer goods, fashion, and lifestyle categories. Its documented focus is profitable growth across the full funnel, with email as one component of the retention side of that model.

Pricing signal -- Common Thread Collective operates on a retainer model. Entry-level engagements for brands below $10M in revenue are limited -- the agency is optimized for brands above that threshold. Retainers vary with the scope of channels managed, and the email component through Klaviyo is priced as part of a broader engagement rather than as a standalone service.

What to watch -- Common Thread Collective is a growth agency, not a Klaviyo specialist. Its email work is strong within the context of a full-funnel growth program but is not the deepest Klaviyo practice on this list. For brands that need advanced lifecycle programs, complex segmentation, or deliverability management at scale as the primary deliverable, a Master Elite specialist will outperform. The fit is strongest when email retention is one of several channels the brand wants managed together within a profitable growth framework.

• Best for: DTC brands between $10M and $100M in revenue seeking a full-funnel growth partner with email retention as one coordinated component

• Specialization: DTC growth, paid media, content, email and retention through Klaviyo, profitable growth frameworks

• Pricing: Retainer-based; optimized for $10M-plus DTC brands

• Clutch: Verify on Clutch before engaging

8. Electric Eye

Electric Eye is a Shopify Plus design and optimization agency that builds Klaviyo implementations as part of its broader ecommerce development work. Listed in Shopify's partner directory, it focuses on DTC brands running on Shopify or preparing to migrate to Shopify Plus. Its Klaviyo work lives at the development layer: building the integration between the Shopify store and Klaviyo, configuring the event schema, setting up catalog feeds, and implementing the base flow architecture that a brand's email program runs on -- before handing off to a marketing team or managed-service agency for ongoing execution.

Electric Eye's role is implementation, not management. The distinction matters for buyers. A managed-service agency runs your Klaviyo account. An implementation firm builds the technical foundation that a managed-service agency or in-house team operates on. Electric Eye is the right partner at the moment a brand sets up Klaviyo for the first time, migrates from a different email service provider and needs the integration rebuilt, or moves to Shopify Plus and needs the Klaviyo integration reconstructed to match the new platform's data structure.

The Shopify-native scope is both a strength and a boundary. For brands on Shopify or Shopify Plus, the Klaviyo integration is well-defined: Shopify's native Klaviyo connector covers most standard event schemas, the product catalog sync is handled by the native integration, and the segment logic runs off Shopify order and customer data. Electric Eye knows that setup deeply. It understands where the native integration has gaps -- multi-currency stores, complex product variants, subscription billing through Recharge -- and how to handle them at the Shopify layer. For brands on custom backends, headless architectures outside the Shopify ecosystem, or proprietary systems, the native integration does not apply and the work requires an API-first engineering approach that falls outside Electric Eye's core scope.

Notable work -- Electric Eye is listed in Shopify's partner directory with a documented focus on DTC brand builds and Shopify Plus migrations. Its Klaviyo implementation work is part of its broader ecommerce optimization practice. Named client references are available on its website.

Pricing signal -- Electric Eye does not publish fixed Klaviyo-only pricing. Implementation engagements are typically project-based, often bundled with a broader store build or platform migration. Standalone Klaviyo implementation projects start in the $5,000 to $20,000 range depending on scope, the complexity of the event schema, and the number of flows and segments configured at handoff.

What to watch -- Electric Eye is a Shopify-native implementation firm. It is not a lifecycle marketing agency and does not manage ongoing email programs after handoff. For brands on non-Shopify platforms, or brands that need deep API-level integration work for non-standard event schemas or custom backend systems, the scope requires a different partner. Confirm platform compatibility during scoping.

• Best for: Shopify and Shopify Plus brands setting up or rebuilding their Klaviyo integration at the development layer before handing off to a managed-service agency

• Specialization: Shopify Plus development, Klaviyo implementation, ecommerce design and DTC optimization

• Pricing: Project-based; implementation typically $5,000-$20,000

• Clutch: Verify on Clutch before engaging

Side-by-side comparison

The integration layer decides the email results

The most common way Klaviyo investments underperform is not a creative problem or a strategy problem. It is a data problem. A brand hires a lifecycle agency, the agency builds flows, the flows fire -- but the events arriving in Klaviyo are incomplete, delayed, or missing entirely. The abandoned cart flow fires on 60% of the carts because the other 40% come from a mobile app that has never been instrumented for Klaviyo. The post-purchase sequence triggers on Shopify orders but misses the 25% of orders processed through a custom ERP that was never connected to the Track API. The win-back segment pulls on last order date from Shopify but ignores the subscription orders coming from a Recharge account that hasn't been synced to Klaviyo's customer profiles, so the segment flags active subscribers as lapsed buyers and sends them a discount they never needed. These failures are invisible in the Klaviyo interface until you compare event counts against actual transaction counts and see the gap.

That gap is why this list divides into two types of company, and why getting the type right matters before getting the brand right.

The first type is the managed-service lifecycle agency. SmartBug Media, Chronos Agency, Flowium, Hawke Media, and Common Thread Collective are agencies that run Klaviyo programs for brands. They own strategy, creative, platform configuration, and ongoing optimization. Their results are bounded by the completeness of the Klaviyo data layer. A Master Elite agency on a broken integration is slower and more expensive than a mid-tier agency on a clean one, because the first months of the engagement go toward diagnosing problems that should have been fixed before the retainer started.

The second type is the technical integration partner. RaftLabs builds the data layer that the managed-service agency runs on. It designs event schemas, builds catalog sync pipelines, wires CDP feeds, and implements webhook architectures that feed accurate data into Klaviyo from every system a brand runs. Its work is a precondition for a managed-service agency's performance, not a replacement for it.

Electric Eye sits in a middle position: it is a Shopify-native implementation firm that builds the Klaviyo integration as part of a platform build or migration, handing off a clean technical foundation to a managed-service agency for ongoing execution. Its scope is narrower than RaftLabs on the engineering side -- it works within Shopify's native connectors rather than building API-first from scratch -- but it is the right partner at the right moment for brands whose Shopify Plus migration is the primary event.

Groove Commerce occupies a third position: it builds the ecommerce platform and the Klaviyo integration in the same engagement, removing the seam between platform and email program at the moment a brand goes live. For brands that are building the store and starting Klaviyo simultaneously, Groove Commerce's dual-track model is more efficient than coordinating a platform agency and a lifecycle agency separately.

The right engagement sequence for most brands is: audit the integration first, fix what is broken, then hire the managed-service agency. For a brand on Shopify Plus with a clean native integration, that sequence is fast. For a brand on a custom backend or a hybrid system, the integration work is substantial, and scoping it before any lifecycle agency retainer begins saves several months of underperformance.

"When Apple, one of the largest tech companies in the world, is willing to bet on first-party data and owned relationships, that tells you where consumers are heading."

Andrew Bialecki, Co-founder and CEO, Klaviyo

Klaviyo now serves over 167,000 businesses globally (Klaviyo FY 2024 Results), with approximately 3.8 billion emails sent through the platform every month. The platform's growth is not happening because email is a new idea. It is happening because first-party behavioral data -- what a customer viewed, what they added to cart, what they bought, how long they waited between purchases -- is the most accurate signal a brand can use to predict what a customer will do next, and Klaviyo is the system that turns that signal into revenue. Email generates an average ROI of $36 for every $1 spent (Litmus). That number is built on the quality of the data. A brand with clean, complete Klaviyo data earns close to that figure. A brand with a half-instrumented Klaviyo account earns a fraction of it, and attributes the gap to the agency rather than the data layer.

Five questions to ask before signing

What is the current state of our Klaviyo data layer?

Before signing any Klaviyo agency retainer, audit the integration. Pull event counts from Klaviyo and compare them against actual transaction counts from your order management or ERP system. Check whether mobile app events are instrumented. Confirm whether subscription orders from Recharge or another billing platform are arriving in Klaviyo. Verify that the product catalog is syncing in real time and that the properties attached to catalog items match what Klaviyo's dynamic product blocks expect. If any of these checks reveal gaps -- and for brands not on Shopify Plus with a clean native integration, gaps are common -- those need to be fixed before the managed-service retainer begins. An agency that starts on a broken integration will spend its first months diagnosing problems rather than driving performance, and the retainer costs during that discovery period are not recoverable.

What is your partner tier with Klaviyo, and what does that mean in practice?

Klaviyo's partner tiers -- Master Elite, Elite, Platinum, and Partner -- reflect the volume of Klaviyo accounts managed, the revenue generated through the platform, and the technical certification depth across the agency team. Master Elite status gives an agency priority access to Klaviyo's product team, beta features, and dedicated technical support. That matters when a deliverability issue needs escalation to Klaviyo's infrastructure team, when a new Klaviyo feature needs early access before general availability, or when a platform bug requires a fix at the Klaviyo level rather than the account level. Ask every agency for its current tier and what that tier gives you in practice, not just in marketing copy.

How do you manage deliverability, and what happens when sender reputation drops?

Email deliverability is the unsexy problem that kills Klaviyo performance faster than any creative or strategy issue. A list with too many inactive contacts, a send rate that increases too quickly, a domain that was not warmed correctly after a platform migration, or a segment that includes invalid and role-based addresses -- any of these can push a brand's email into spam folders across Gmail, Yahoo, and Outlook within a few sends. Ask every agency how it manages suppression logic and list hygiene, how it approaches domain and IP warming after a migration, how it tracks deliverability metrics beyond open rate, and what the escalation protocol is when sender reputation drops. A blank or vague answer here is a warning sign, because deliverability problems are far cheaper to prevent than to fix.

How does your email calendar coordinate with the rest of our marketing stack?

A promotional email that arrives in the inbox the same day as a high-spend paid campaign can amplify one or cannibalize the other, depending on how they are timed and what they say. A win-back email that fires when a customer is mid-conversation with the support team -- perhaps about a return or a defect -- accelerates churn rather than recovery. A post-purchase sequence that follows up at the same time as an influencer post the brand has already paid for misses the moment to amplify both signals. Ask every agency how it coordinates the Klaviyo calendar with paid advertising, influencer activity, PR events, and seasonal planning. An agency that manages email in isolation from the rest of marketing creates conflicts rather than compounding results.

Who owns the account, the flows, and the data when the engagement ends?

Klaviyo accounts, flow configurations, segment logic, template assets, and API credentials are durable assets. Ask every agency: is the Klaviyo account held under the brand's own subscription or under the agency's master account? If the account is under the agency's master account, what is the handover process if the engagement ends? Who holds the API keys and integration credentials? Are the flows and templates exportable and documented in a way that a new team or agency can take over without rebuilding from scratch? A brand that cannot access its own Klaviyo account at engagement end is locked out of its own retention program, and rebuilding from scratch -- including the event history and segmentation logic -- takes months and costs revenue. Confirm ownership and handover terms before signing, not after a relationship ends badly.

The verdict

SmartBug Media for brands that want the deepest managed Klaviyo program with full lifecycle ownership and HubSpot crossover. Chronos Agency for DTC brands that want an LTV-focused retention partner with execution depth across 500-plus brands and $400M-plus in email-attributable revenue. RaftLabs for ecommerce brands on custom or non-standard backends that need Klaviyo's data layer engineered from the ground up -- custom events, catalog syncs, CDP integration, webhook triggers -- with one accountable team. Flowium for brands that want retention-focused lifecycle marketing with multi-channel coordination across email, SMS, and push. Groove Commerce for brands building on Shopify Plus, BigCommerce, or Magento that want the platform and the Klaviyo integration delivered in one engagement. Hawke Media for brands that want email running as part of a full-service digital marketing relationship coordinated with paid and social. Common Thread Collective for DTC brands above $10M that want email inside a full-funnel profitable growth program. Electric Eye for Shopify brands setting up or rebuilding the Klaviyo integration at the development layer before handing off to a marketing team.

The decision simplifies when you answer two questions clearly: is your Klaviyo data layer technically sound, and do you need someone to build that layer or someone to run the programs on top of it? Get those two questions right, and the shortlist above narrows to one or two names quickly. Skip them, and even the best agency on this list will spend their first months on problems you already had.

RaftLabs designs and builds Klaviyo integrations and growth marketing infrastructure -- custom event tracking, product catalog syncs, CDP wiring, and webhook-driven triggers -- in one team from data layer to production. No handoff gap. 4.9/5 on Clutch across 50+ verified reviews. Talk to a founder about your Klaviyo integration.