Payment Gateway Integration Services

Payment Gateway Integration Services | RaftLabs

See our work

  • Stripe, PayPal, Braintree, Square, Razorpay -- gateway-agnostic

  • Subscription billing, usage-based pricing, and marketplace revenue splits

  • Webhook handling and payment reconciliation built into the integration

Recent outcomes

Voice AI · Research

Text-based interviews converted to automated phone calls

6× deeper insights

AI Automation · Ops

Manual invoice OCR across 40+ gas stations

20k+ txns day one

Loyalty · Retail

SuperValu & Centra loyalty platform with receipt validation

1,062 users in 4 weeks

SaaS · Logistics

Multi-carrier shipping hub for Indonesian eCommerce

2,000+ shipments yr 1
4.9 / 5 on ClutchSee all work

Recognition

Sound familiar?

  • Your checkout converts fine but your refund and subscription logic is a mess of manual workarounds in the admin panel?

  • You need to split payments between multiple sellers on your marketplace but your current setup pays everyone in one lump sum manually?

  • You want to accept payments in multiple currencies but your gateway setup can only handle one country?

In short

RaftLabs provides payment gateway integration services -- connecting Stripe, PayPal, Braintree, Square, Razorpay, and custom acquirers into web apps, mobile apps, SaaS platforms, and marketplace software. The studio handles subscription billing logic, refund workflows, webhook handling, and revenue splits for multi-vendor platforms. Most payment integrations take 2--6 weeks depending on billing complexity.

Trusted by

Vodafone
Nike
Microsoft
Cisco
T-Mobile
Aldi
Heineken
GE

RaftLabs integrates payment gateways into custom software -- web apps, mobile apps, SaaS platforms, and B2B portals. Not copy-pasting a Stripe JS snippet. The work is the billing logic: subscription states, refund workflows, webhook reliability, and revenue splits that hold when your transaction volume grows.

Most payment bugs aren't gateway bugs. They're logic bugs: a refund that partially updates a subscription, a webhook that fires twice and charges a customer twice, a marketplace that settles the wrong amount to a seller. The integration has to model your billing correctly or the failures compound.

Capabilities

Payment integration services

  • 01

    Stripe integration

    Stripe Checkout, Stripe Elements, and Stripe Billing configured for your product's pricing model. Subscription plans, free trials, proration on plan changes, usage-based billing via Stripe Metered Billing, and the customer portal for self-serve plan management. Stripe Connect for marketplace platforms paying out to multiple sellers. Webhook handling for all critical Stripe events -- payment failures, subscription renewals, disputes, and refunds -- with idempotency keys so double-firing doesn't produce double charges.

  • 02

    Subscription billing systems

    Subscription logic built on top of your chosen gateway. Plan tiers with monthly and annual options, trial periods with conversion tracking, mid-cycle plan upgrades and downgrades with proration calculated correctly, and dunning flows for failed renewals. Customer billing portal so users can manage their own subscription without contacting support. The logic that looks simple on paper but breaks in edge cases -- mid-trial upgrades, annual plans on monthly billing cycles, coupons applied to recurring charges -- handled before it hits production.

  • 03

    Marketplace payment splitting

    Payment flows for platforms where revenue goes to multiple parties. Stripe Connect, PayPal for Marketplaces, or Braintree Marketplace configured for your split model. Funds held in escrow until fulfilment conditions are met, then released to sellers on your payout schedule. Platform fee deducted before seller payout. Seller onboarding flow with identity verification (KYC) required by the gateway. Seller dashboard showing earnings, payout history, and payout schedule.

  • 04

    PayPal and Braintree integration

    PayPal Checkout and Braintree Drop-in UI for platforms where buyer trust and PayPal wallet acceptance matter. Braintree's vaulted card storage for repeat purchases without re-entering card details. PayPal's buyer protection messaging in checkout for B2C platforms where trust signals affect conversion. Recurring billing via Braintree's subscription API for SaaS products targeting markets where PayPal is the preferred payment method.

  • 05

    Multi-currency and international payments

    Gateway configuration for accepting payments in multiple currencies. Currency detection by buyer location, price display in local currency, settlement in your base currency. Stripe's multi-currency presentment and PayPal's multi-currency support configured with the right decimal handling per currency. Tax calculation integration (Stripe Tax or TaxJar) for platforms selling across tax jurisdictions.

  • 06

    Webhook handling and payment reconciliation

    Webhook endpoints built with proper signature verification, idempotency, and retry logic. Events processed in order for subscriptions -- payment intent created, payment succeeded, invoice finalized -- so your application state matches the gateway state. Reconciliation logging so you can audit any transaction and confirm your records match the gateway's. Alerting for webhook delivery failures and payment events that require manual review.

  • 07

    Gateway migration

    Moving from one payment gateway to another without interrupting active subscriptions. Token migration from Braintree, Adyen, or a legacy direct integration to Stripe. Subscription state mapping so active subscribers carry over without being charged twice or losing their billing cycle. Cutover executed during a low-traffic window with a fallback plan if the migration produces unexpected failures.

Process

How payment integrations are built

Five steps from initial billing requirements to a production payment system with documented edge-case handling.

  1. Week 1
    01

    Billing requirements and gateway selection

    We document your exact billing model -- one-time charges, subscriptions, usage-based billing, marketplace splits, or a combination. We review your geography, target customer segments, and existing tech stack, then recommend the right gateway or gateway combination. Gateway selection at this stage is cheaper than migrating six months later.

  2. Week 1
    02

    Integration architecture

    Before writing integration code, we map the full payment flow: checkout entry points, gateway API calls, webhook events and handlers, database state changes at each event, and the failure modes that need explicit handling. Edge cases documented before the first line of integration code: what happens when a webhook fires twice, when a subscription renewal fails on the third retry, when a refund is requested for a partially delivered order.

  3. Weeks 1--4
    03

    Integration build and webhook setup

    Gateway SDK integration in your application stack. Payment form or checkout flow built and tested against the gateway's test environment. Webhook endpoint built with signature verification, idempotency keys, and event-ordered processing. Subscription billing logic -- plan creation, trial handling, proration, dunning -- implemented against the staging environment. Every integration tested against the gateway's test card set before touching a live key.

  4. Weeks 3--5
    04

    Edge-case testing and reconciliation audit

    Test suite covering the cases that break in production: duplicate webhook delivery, payment failure mid-subscription cycle, refund on a subscription that has already renewed, plan change mid-trial, payout to a seller whose account has been flagged. Reconciliation audit: confirm your application's payment records match the gateway's transaction log for every test scenario.

  5. Final week
    05

    Production cutover and monitoring

    Live gateway credentials configured, production environment validated with a real transaction. Monitoring alerts set for payment failures above a threshold, webhook delivery failures, and refund rates. Runbook for the most common payment operations your team will handle post-launch: issuing refunds, pausing subscriptions, updating card details, and investigating disputed charges. Your team handles payment operations independently after handover.

Payment logic that breaks costs you customers. Get it right the first time.

Tell us your billing model -- subscriptions, marketplace, one-time, or a mix -- and your current tech stack. We'll scope the integration and give you a cost estimate before work starts.

Talk about your payment integration

Related services

What clients say

What clients say about working with us

Three-year average engagement. Founders and operators describing the work in their own words. No marketing varnish.

Niccolo Pescetelli
Niccolo Pescetelli
Co-founder & Director, PSi

Working with RaftLabs felt like having an extension of our own team. They're extremely nimble and responsive, adapting quickly to changing startup needs. I highly recommend them, especially for small and mid-sized companies.

01 / 14

Recent work

Projects that started like yours

AI phone agents conducting automated voice interviews at global scale

We rebuilt a text-based AI interview platform as a voice-first system that conducts automated phone interviews globally, removing user friction and surfacing richer insights through natural conversations.

Read case study
AI Phone Agent To Conduct Voice Interviews at Scale
Gas Station Management Software Case Study

AI-powered OCR scaling gas station operations to 20k+ daily transactions

This purpose-built gas station inventory management software uses AI-based OCR to automate invoice processing and unify inventory, sales, and vendor tracking. Designed for scale, it gives owners real-time control across 40+ locations, without disrupting existing POS systems.

Read case study
Multi Carrier Shipping Software

Multi-carrier shipping SaaS: 2,000+ shipments across 70+ countries in year one

We developed a multi-carrier shipping SaaS solution in Indonesia, helping fast-growing eCommerce businesses ship globally with ease. Integrated with Shopify, it offers instant Aramex, FedEx, DHL, and UPS rate comparisons, automated fulfilment, and end-to-end shipment management.

Read case study
AI OCR Loyalty Platform for SuperValu and Centra
Loyalty · Retail

SuperValu and Centra needed a loyalty platform. We shipped one that acquired 1,000+ users in 4 weeks.

We built an AI-powered loyalty platform for Musgrave's SuperValu and Centra that automates receipt validation with 99.9% accuracy, acquiring 1,062 users in 4 weeks.

Read case study
See all projects

Still curious?

A single gateway integration with basic checkout, webhooks, and refund handling typically runs £3,000--£8,000. A full subscription billing system with plans, trials, proration, and customer portal runs £8,000--£20,000. Marketplace payment splitting with escrow, payout scheduling, and seller dashboards runs £15,000--£35,000+.

Stripe (most common for SaaS and international), PayPal and Braintree (B2C and buyer-trust markets), Square (retail and hospitality), Razorpay (India), Adyen (enterprise international), and custom banking API integrations for specific acquirers. We recommend the right gateway for your geography and business model before integration starts.

Payment processing itself stays with the gateway -- Stripe, PayPal, and Braintree are PCI Level 1 certified, which means card data never touches your server. We build integrations that follow tokenisation best practices so you stay out of PCI scope. If you need a SAQ-A or SAQ-A-EP assessment, we can advise on documentation.

Yes. Gateway migrations involve exporting existing subscriber and card token data, mapping subscription states, and handling the cutover without interrupting active subscriptions. We have migrated SaaS platforms from Braintree to Stripe and from legacy direct integrations to Stripe Billing. The critical path is token migration -- most gateways support token export on request.

Yes. Stripe Billing and Paddle cover most SaaS pricing models out of the box -- we configure them and build the customer-facing subscription portal. For usage-based billing (metered by API calls, storage, seats), we build the metering infrastructure that feeds into Stripe Metered Billing or a custom billing engine.

Work with us

Tell us what you need. We'll tell you what it would take.

We scope Payment Gateway Integration Services | RaftLabs in 30 minutes. You walk away with a clear cost, timeline, and approach. No commitment required.

  • Scope and cost agreed before work starts. No surprises. No obligation.
  • Working prototype within 3 weeks of kickoff.
  • Pay by milestone. You see progress before each invoice.
  • 60-day post-launch warranty. Bug fixes, UI tweaks, and deployment support. No retainer.
  • All conversations are NDA-protected.