Top legacy modernization companies (August 2026 Update)

Every legacy modernization project starts with a demo of the new system and fails somewhere in the old one. The new interface looks clean. The new stack is modern. Then the data migration runs for the first time and a set of records will not map, because a field that should hold a number holds free text somebody typed in 2011. Or the old system carries a pricing rule that lives nowhere except the code, and the rebuilt version gets it subtly wrong. Or the cutover weekend arrives, the switch flips, and there is no way back when a core report comes up empty. Legacy modernization lives and dies on the parts a demo cannot show: how clean the old data really is, which business rules are hiding in undocumented code, and how the old system stays alive while the new one comes up. The companies on this list have finished modernizations where those decisions were made in the first phase, not discovered at go-live.

The reason this category is hard to buy well is that the shortlist you build from a directory search all looks the same. Every firm claims modernization, every profile shows a rating, and every sales call opens with the same cloud-and-microservices pitch. What separates a firm that will land a working system from one that will hand you a stalled rewrite is invisible until you ask the right questions: how they assess an old system before touching it, how they choose between refactor and rewrite, how they migrate live data without losing it, and what they got wrong on a past modernization and how they fixed it. This guide is organized around those questions, not around logos. We looked at proven modernization track record, depth in the areas modernization actually depends on, pricing transparency, fit with the kind of buyer reading this, and honest limitations -- because the wrong-fit firm is more expensive than the more expensive firm.

The eight legacy modernization companies on this list are GFT Technologies, RaftLabs, Endava, Nortal, Scalefocus, Avenga, Devox Software, and Keyhole Software. RaftLabs is on this list. We wrote our own entry with the same directness we applied to everyone else.

How we evaluated this list

A buyer's guide is only as honest as its criteria, so here are ours before the companies. We did not rank on rating alone -- a high score on a directory tells you clients were happy, not that a firm has finished a migration without losing data. We weighted proof of real modernization work, discipline around assessment and migration, transparency on how work is priced, fit with the reader's profile, and honesty about approach. Where a firm's rating could not be verified against a live profile during sourcing, we say so and hedge rather than repeat a number we could not confirm.

We evaluated companies on five criteria:

No company paid for placement on this list.

1. GFT Technologies

GFT Technologies is a publicly traded engineering firm with more than three decades in financial services, headquartered in Germany and delivering worldwide. It is best known for core-banking modernization, capital-markets and trading platforms, and custom insurance systems. For a bank or insurer sitting on an aging mainframe or a decades-old core, that depth is hard to match with a generalist. Modernizing a core banking system is not a normal software project. The rules are dense, the data is old, and a wrong migration is a regulatory event, not a bug.

GFT positions itself as an enterprise partner, which means it is built for large, regulated, high-stakes modernizations rather than a quick re-platforming of one app. That suits a bank replacing a core system. It is a heavier fit than a growing company needs to modernize a single internal tool.

The reason a long financial-services history matters here, rather than reading as marketing, is that core modernization carries patterns a team either has lived through or has not. A core banking migration has to reconcile to the cent across millions of accounts. It has to run the old and new ledgers in parallel long enough to prove they agree. It has to satisfy a regulator that nothing was lost in the move. A firm that has done this before will raise reconciliation and parallel running on the first call. A generalist raises them after the first failed reconciliation. Ask GFT, or any firm here, to describe the trickiest core migration it has landed and how it proved the data matched.

Notable work -- Specific client engagements are not verified here. GFT is a well-documented financial-services engineering firm with a long public track record in core-banking and capital-markets modernization. Ask for references in your specific system, regulator, and country footprint before signing.

Pricing signal -- Pricing is not publicly listed; work is enterprise and engagement-based. Expect enterprise financial-services consulting economics rather than a startup rate band, and confirm scope directly.

What to watch -- GFT is built for large, regulated modernizations, most naturally in banking and insurance. A growing company modernizing a single application, or a buyer outside financial services, may find the enterprise model heavier and more expensive than the job needs.

• Best for: Banks and insurers modernizing a core system where regulatory weight and reconciliation depth are the hard part.

• Specialization: Core-banking modernization, capital-markets platforms, custom insurance systems

• Pricing: Not publicly listed; enterprise and engagement-based

• Clutch: Profile listed; confirm rating before engaging

2. RaftLabs

RaftLabs is an AI-first tech studio that has built and modernized custom software for established businesses since 2015. Its legacy software modernization and re-platforming work centers on the parts of a modernization that decide whether it lands: an honest assessment of the old system before anyone writes new code, recovery of the business rules buried in that code, a tested data migration, and a phased cutover that keeps the old system running until the new one is proven. Engagements start with a scoped assessment that maps the data, the dependencies, and the hidden rules before the build is priced.

The reason that order matters is specific to modernization. The migration and the cutover are where these projects fail, so RaftLabs treats them as the first decisions rather than the last. The choice between refactor, re-platform, and rewrite is made after reading the system, not before, because a rewrite recommended on day one is usually a firm selling a bigger project rather than solving the real problem.

In practice the assessment produces two artifacts before design starts: a data map that says exactly where every record lives, how clean it is, and how it will move, and a rules inventory that captures the behavior hiding in the old code -- the regional discount, the currency rounding, the approval that skips a step. Those two documents are where most of the real cost and risk live, and pinning them down early is what lets a fixed price hold. It is also what makes the difference at cutover. A phased migration, run one module at a time with the old and new systems in parallel, means a problem surfaces on one module while it is cheap to fix, not across the whole business on a Saturday night. RaftLabs runs assessment precisely so the edge cases are named while they are cheap, in the plan, rather than discovered after go-live when they mean a rollback.

Notable work -- RaftLabs has shipped 30+ products since 2015 for clients including Vodafone and T-Mobile, evidence of building and re-platforming at enterprise scale with the reliability legacy migrations demand. It has not published a standalone core-migration case study on this list, so ask to see relevant re-platforming, data-migration, and integration work directly during scoping.

Pricing signal -- $29-$49/hr with fixed-price engagements and milestone payments, scoped after the assessment that maps the data and the hidden rules. Fixed-price suits buyers who want a known number before migration complexity is priced in.

What to watch -- RaftLabs owns the full delivery stack -- assessment, architecture, engineering, and cutover -- which fits businesses that want one team accountable end to end for a modernization. A bank replacing a regulated core system at the largest scale, or a company that only needs a single specialist added to an internal team, is better served by an enterprise core-banking specialist or a staff-augmentation partner.

• Best for: Growing companies and enterprises modernizing a business-critical system end-to-end without building an internal team for it.

• Specialization: Legacy modernization and re-platforming, data migration, business-rule recovery, assessment-led delivery

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

• Clutch: 4.9/5

3. Endava

Endava is a publicly listed enterprise software engineering firm, headquartered in London, delivering digital transformation and modernization across Europe and the Americas. It works at scale for large organizations, with a strong presence in financial services, payments, and other regulated sectors. For an enterprise modernizing a portfolio of systems rather than a single application, Endava's scale and delivery breadth are a genuine fit.

Endava reads as a partner for the large, multi-year transformation -- the kind where modernization runs across many teams and many systems at once. Its listed-company scale gives a buyer a stable partner for a long program. That same scale is more than a mid-market buyer with one system to modernize typically needs.

The useful test for an enterprise modernization partner is whether it can run change across many systems without losing coherence. A portfolio modernization has to sequence the work so that dependencies do not break -- you cannot migrate the system that everything else reads from until the readers are ready. It has to keep a consistent architecture across teams that would otherwise each invent their own. A firm with real transformation experience will talk about sequencing and dependency management early. Ask Endava to walk through how it sequenced a past multi-system modernization and how it handled the system that everything else depended on.

Notable work -- Specific client engagements are not verified here. Endava is a well-documented, publicly listed engineering firm with a long transformation track record in financial services and payments. Ask for references in your sector and, critically, for a modernization of similar scope and sequencing complexity before signing.

Pricing signal -- Pricing is not publicly listed; work is enterprise and program-based. Expect enterprise economics scaled to a multi-team engagement, and confirm scope and team composition directly.

What to watch -- Endava is built for large, multi-system transformation programs. A company modernizing a single application, or one that wants the lowest rate on this list, will find a smaller studio a closer fit than an enterprise program partner.

• Best for: Enterprises running a multi-year, multi-system modernization program that needs consistent delivery across many teams.

• Specialization: Enterprise digital transformation, financial services and payments, large-scale delivery

• Pricing: Not publicly listed; enterprise and program-based

• Clutch: Profile listed (few public reviews); confirm rating before engaging

4. Nortal

Nortal is an enterprise technology firm headquartered in Tallinn, Estonia, with offices across Europe, North America, and the Middle East. It is known for building and modernizing national-scale systems in healthcare and government, where the data is enormous, the stakes are public, and downtime is not an option. That pedigree matters for modernization. A team that has migrated a national health or benefits system has learned migration discipline the hard way.

Nortal reads as a fit for a buyer modernizing a system with real public or population scale, or one where reliability and data integrity carry unusual weight. Its ISO 9001 and 27001 certifications give a buyer a documented process to inspect, though its directory review base is thinner than some smaller firms on this list.

The transfer from national-scale public systems to enterprise modernization is more direct than it looks. When a team modernizes a system that a whole country depends on, it learns to migrate in stages, to prove data integrity before switching anything off, and to plan for the failure that cannot be allowed to become an outage. Those instincts map straight onto any business-critical modernization. A firm that has kept a national health record running through a migration will treat your cutover with the same caution. Ask Nortal to walk through how it staged a large public-sector migration and how it guaranteed no records were lost in the move.

Notable work -- Nortal states national-scale healthcare and public-sector work in the Baltics and Nordics on its own site; specific engagements are vendor-stated rather than independently verified here. Ask for references at a scale and in a sector close to yours, and for evidence of a completed migration.

Pricing signal -- Pricing is not publicly listed; work is enterprise and engagement-based. Nortal holds ISO 9001 and 27001 certifications, so ask to see the process documentation behind them during scoping.

What to watch -- Nortal is built for large, high-integrity modernizations, most naturally in healthcare and government. A small commercial buyer modernizing a single tool may find the enterprise and public-sector orientation heavier than the job requires.

• Best for: Organizations modernizing a system with public or population scale, where data integrity and uptime carry unusual weight.

• Specialization: National-scale healthcare and government systems, high-integrity data migration

• Pricing: Not publicly listed; enterprise and engagement-based

• Clutch: Ratings not verified; confirm before engaging

5. Scalefocus

Scalefocus is an enterprise software engineering firm based in Sofia, Bulgaria, delivering cloud, data, and AI work for large organizations across Europe and North America. Its strength is enterprise-grade engineering at a rate below the premium US and UK tier, which makes it a credible option for a growing company or mid-market enterprise modernizing a real system without a top-tier consulting bill.

Scalefocus reads as a fit for a buyer who wants enterprise engineering discipline -- cloud migration, data platforms, integration -- at an accessible rate, with a verified review base to read the delivery pattern from. Its focus is broad engineering rather than a single named legacy-modernization practice, so confirm the specific migration experience you need.

The value of a broad enterprise engineering firm in a modernization is that most modernizations are not only about the old code. They pull in cloud migration, a rebuilt data platform, and new integrations at the same time. A firm that does all of those routinely can carry the whole job rather than handing pieces to subcontractors. The caveat is symmetrical: because the practice is broad, you should confirm that the specific thing you are modernizing -- a particular old stack, a particular kind of data migration -- is something the assigned team has done before, not just something the firm can staff. Ask Scalefocus to show a modernization close to yours and to name the engineers who did it.

Notable work -- No specific modernization engagement is verified here. Scalefocus's public profile centers on enterprise cloud, data, and AI engineering. Ask for a modernization case study close to your stack and a live reference before signing.

Pricing signal -- $50-$99/hr per its Clutch profile, a mid-market band for an enterprise engineering firm delivering from Bulgaria -- below the premium US and UK tier for comparable scale.

What to watch -- Scalefocus's strength is broad enterprise engineering. If your modernization is narrow and specialized -- a single legacy stack with an unusual data problem -- confirm the assigned team has done that specific work, not just that the firm operates at enterprise scale.

• Best for: Mid-market and enterprise buyers wanting enterprise-grade cloud and data modernization at an accessible rate.

• Specialization: Enterprise software engineering, cloud migration, data platforms, AI

• Pricing: $50-$99/hr per Clutch

• Clutch: 4.9/5 (39 reviews)

6. Avenga

Avenga is a custom software engineering firm headquartered in Prague, delivering across Europe with a strong financial-services practice -- digital banking, fraud detection, and data and AI integration for banks. For a financial-services buyer modernizing a system that has to keep running while it changes, a firm that lives in banking brings the right instincts about risk, data, and integration.

Avenga reads as a fit for a buyer in banking or a data-heavy sector who wants a modernization partner with a verified review base and financial-services depth, at a mid-market rate. Its strength is engineering inside regulated, data-intensive domains rather than the largest core-replacement programs.

The reason financial-services experience earns attention in a modernization is that banking teams internalize two habits that transfer everywhere. They treat every data movement as something that has to reconcile, and they treat every integration as a contract that other systems depend on. Both habits are exactly what a safe modernization needs. A firm that has modernized a fraud or payments system without breaking the flows around it will approach your integrations with the same care. Ask Avenga to describe a modernization where it had to keep a live financial flow running through the change, and what it did to make sure nothing dropped.

Notable work -- No specific modernization engagement is verified here. Avenga's verified strength is financial-services software engineering, including digital banking and fraud work. Ask how that reconciliation and integration discipline maps to your modernization, and request a completed migration reference.

Pricing signal -- Around $50-$99/hr per its Clutch profile, with project minimums reported in the tens of thousands. A mid-market band consistent with a financial-services engineering firm delivering from Central Europe.

What to watch -- Avenga is strongest in financial services and data-heavy domains. A buyer well outside those sectors should confirm the assigned team has modernized systems like theirs, rather than relying on the banking track record alone.

• Best for: Banking and data-intensive buyers modernizing a system that must keep running through the change.

• Specialization: Financial-services engineering, digital banking, fraud detection, data and AI integration

• Pricing: $50-$99/hr per Clutch

• Clutch: 4.8/5 (73 reviews)

7. Devox Software

Devox Software is a custom software firm headquartered in Miami, with delivery teams in Poland and Ukraine, that names legacy modernization as a stated practice alongside SaaS and AI and machine-learning engineering. Its focus is mid-market and enterprise modernization, which suits a growing company that has outgrown an old system and needs it rebuilt without a top-tier consulting bill.

Devox reads as a fit for a mid-market buyer who wants a modernization partner with a named modernization practice and a nearshore delivery model at an accessible cost. Its review base is self-reported in the directories we checked, so treat the rating as unconfirmed and verify it against a live profile.

The reason a stated modernization practice is worth probing, rather than taking at face value, is that the label is easy to claim and hard to prove. Any firm can add legacy modernization to a services list. The test is whether it can show a finished migration and describe the migration and cutover in detail. A firm that genuinely modernizes systems will talk fluently about profiling dirty data, recovering undocumented rules, and running old and new in parallel. A firm that only builds new products will pivot the conversation back to the shiny new stack. Press Devox to walk one completed modernization end to end -- the old system, the approach it chose, the data migration, and what surprised it -- and judge the depth of the answer.

Notable work -- No specific modernization engagement is verified here. Devox states a legacy-modernization practice for mid-market and enterprise clients. Ask for a finished modernization case study, a live reference, and a walkthrough of how it migrated the data before signing.

Pricing signal -- Pricing is not publicly listed; the nearshore delivery model from Poland and Ukraine typically lands below the premium US and UK tier. Request a quote and ask for the assessment phase to be priced separately.

What to watch -- Devox's rating is self-reported in the directories we checked, so verify it directly. Confirm the modernization practice with a completed migration and a reference, not just a services-page claim.

• Best for: Mid-market buyers wanting a named modernization practice with nearshore delivery at an accessible rate.

• Specialization: Legacy modernization, SaaS engineering, AI and machine learning

• Pricing: Not publicly listed; nearshore delivery

• Clutch: Profile listed (rating self-reported); confirm before engaging

8. Keyhole Software

Keyhole Software is a US-based consultancy, headquartered in Lenexa, Kansas, that pairs custom development in transport, logistics, and insurance with a stated legacy-modernization line -- including.NET and Java re-platforming and modernizing older enterprise applications. For a US buyer that wants an onshore team with a modernization focus and close time-zone collaboration, Keyhole is a credible fit.

Keyhole reads as a fit for a buyer who values an onshore, English-first team and a consultancy that names modernization and re-platforming explicitly. Its verified review base is thin, so lean on direct references rather than a directory score.

The value of an onshore modernization consultancy is closeness during the hard parts. Modernization involves a lot of conversations with the people who actually use the old system, because that is where the undocumented rules live. A team in your time zone, speaking your language, can sit in those conversations without a lag. That closeness is worth a higher rate for some buyers and not for others. The trade-off is cost: an onshore US consultancy typically bills above the nearshore and offshore firms on this list. Decide honestly whether the collaboration closeness is worth the premium for your project, or whether a distributed team with strong process would serve you as well at a lower rate.

Notable work -- No specific modernization engagement is verified here. Keyhole states legacy-modernization and re-platforming work in.NET and Java alongside its transport, logistics, and insurance practices. Ask for a finished modernization reference and a walkthrough of a completed migration before signing.

Pricing signal -- Around $100-$149/hr per its Clutch profile, an onshore US consultancy band above the nearshore and offshore firms on this list. Confirm current pricing and scope directly.

What to watch -- Keyhole's verified review base is thin, so validate delivery through direct references. A buyer whose priority is the lowest rate rather than onshore collaboration will find better economics elsewhere on this list.

• Best for: US buyers who want an onshore, close-collaboration team with a named modernization and re-platforming focus.

• Specialization: Legacy modernization,.NET and Java re-platforming, transport, logistics, and insurance software

• Pricing: $100-$149/hr per Clutch

• Clutch: Recognition noted; few verified reviews -- confirm via direct reference

Side-by-side comparison

The question that separates a re-platform from a rewrite

Most buyers compare modernization vendors on rate or review score and get the approach wrong before they get the vendor wrong. The real fork on this list is how you should modernize at all: refactor the system in place, re-platform it onto modern technology with the logic mostly intact, or rewrite it from scratch. Picking a firm before you have answered that question is how companies spend a year and a fortune on a rewrite that a re-platform would have covered, or keep patching a system that genuinely cannot carry the business forward.

Re-platform and refactor partners -- most of the firms on this list, and RaftLabs by default -- serve the company whose old system still holds valuable, hard-won logic that works, where the problem is the technology, the cost of maintenance, or the inability to add anything new. That is the common case, and it is the lower-risk path. Moving proven logic onto a modern stack, or improving it in place, keeps the years of edge cases the old code quietly handles. The best of these firms will assess the system first and recommend the smallest change that solves your actual problem.

Rewrite-capable partners serve the narrow case where the old system genuinely cannot be carried forward -- the technology is dead, the data model is fundamentally wrong, or the business has changed so much that the old logic is a liability rather than an asset. A full rewrite is the highest-risk path in software, because it throws away every edge case the old system learned over the years and rebuilds them from memory. It is sometimes the right call. It is rarely the right first call, and a firm that recommends it before reading your code is selling a project.

There is a practical test for which side of the fork you are on. Ask why the old system hurts. If it hurts because it is expensive to maintain, hard to change, or stuck on technology nobody supports, but the logic inside it is still correct and valuable, that is a re-platform or refactor problem, and a rewrite is overkill. If it hurts because the logic itself is wrong for the business you are now -- the model cannot express what you do, and no amount of re-platforming fixes that -- then a rewrite may be justified. Most systems are the first kind. A firm that insists everything must be rewritten, or one that insists everything can be refactored, is selling its own shape rather than solving your problem.

Getting the approach wrong is more expensive than getting the vendor wrong. A rewrite that solves a problem a re-platform would have handled is a year and a budget spent to recreate what you already had; a refactor forced onto a system that genuinely needed replacing is a slow tax that never ends. Spend the first conversations on the approach, not the price, and the vendor choice gets much easier.

An expert view and a data point worth pricing in

The strongest argument against the default reach for a rewrite comes from Joel Spolsky, the software writer and co-founder of Stack Overflow and Trello, in his widely cited 2000 essay "Things You Should Never Do, Part I":

"They did it by making the single worst strategic mistake that any software company can make: They decided to rewrite the code from scratch."

His point was not that rewrites are never right. It was that teams reach for the rewrite because reading old code is harder than writing new code, and that the old code they are so eager to throw away encodes years of bug fixes and edge cases that a rewrite will rediscover the hard way. That is the pattern every firm on this list has seen. The ones that ship reliably assess before they advise, and they keep the proven logic wherever they can.

The scale of the legacy problem is easy to underestimate. The US Government Accountability Office has repeatedly reported that federal agencies spend roughly 80% of their information-technology budgets on operations and maintenance, much of it keeping aging legacy systems alive rather than building anything new (GAO, "Information Technology: Agencies Need to Develop Modernization Plans for Critical Legacy Systems," 2019). The private sector is not far behind. The reason the figure should shape how you buy, rather than just worry you, is that maintenance cost compounds. Every year a modernization is deferred, more rules get buried, more staff who understood the system leave, and the eventual migration gets riskier. The Standish Group's long-running CHAOS research has found that only around a third of software projects succeed on the first attempt, and modernization projects concentrate their risk in exactly the places a rushed team skips: the data migration, the hidden rules, and the cutover. The firms that put those three in the first phase are the ones that keep a modernization out of the failed majority, and the quote that looks expensive up front is frequently the one that has actually priced the hard parts.

The verdict

GFT Technologies for banks and insurers modernizing a regulated core system where reconciliation and compliance are the hard part. RaftLabs for growing companies and enterprises modernizing a business-critical system end-to-end, with assessment, migration, and rule recovery designed in from the first phase. Endava for enterprises running a multi-year, multi-system transformation program that needs consistent delivery across many teams. Nortal for organizations modernizing a system with public or population scale, where data integrity and uptime carry unusual weight. Scalefocus for mid-market and enterprise buyers wanting enterprise-grade cloud and data modernization at an accessible rate. Avenga for banking and data-intensive buyers modernizing a system that must stay live through the change. Devox Software for mid-market buyers wanting a named modernization practice with nearshore delivery. Keyhole Software for US buyers who want an onshore, close-collaboration team with a modernization and re-platforming focus.

The first filter is the approach: refactor, re-platform, or rewrite. The second filter is the specific weight your modernization carries -- regulatory scale, public-scale data integrity, financial reconciliation, or simply an old system a growing company has outgrown. Match those two questions to the right firm on this list, and confirm the migration and cutover story with a completed reference before you sign.

RaftLabs modernizes and re-platforms legacy systems -- assessment first, phased migration, business-rule recovery, and full source-code ownership from day one -- with one team accountable from assessment to cutover. No handoff gap. 4.9/5 on Clutch. Talk to a founder about your modernization project.