Nobody wants to freeze the roadmap for eighteen months just to get off ASP.NET Web Forms. That’s the bind: the system still bills customers, still runs claims or case files or property records, but every new feature costs more than the last one. Hiring for WinForms or Delphi gets harder every quarter. Security reviews flag the same aging framework twice a year. Meanwhile the obvious fix – a full rewrite – is the riskiest thing on the table, because a multi-year rebuild can sink a roadmap faster than the legacy code ever did.
So the real question isn’t “who can rewrite this.” It’s who can peel a monolith apart in working modules, keep the lights on for existing users, and know when to refactor instead of replace. That distinction – staged modernization versus a ground-up rebuild – is what separates the firms worth a call from the ones selling a generic transformation deck.
How We Narrowed the Field
We started from public delivery evidence, not sales pitches: case studies with named industries and measurable outcomes, service pages that actually describe a modernization method instead of repeating “cloud-native” and “agile” as adjectives, and technical blog posts that show engineers who’ve actually touched WCF, VB.NET, or AngularJS-to-Angular migrations. If a firm’s modernization page read like a copy-pasted cloud strategy pitch with no legacy-specific detail, it got cut early.
We also went through customer feedback on Clutch to see how these firms are rated by teams that actually hired them, not just how they describe themselves. Pricing transparency mattered too – not exact numbers, since most of this market quotes per project, but whether a firm was upfront about engagement models versus vague about scope until a sales call.
Team seniority came up again and again in case studies: whether migrations were staffed by architects who’d done this before, or junior teams learning legacy stacks on a client’s dime. That gap showed up fast once we looked past the marketing language.
Context H2
The modernization market splits into two camps that get lumped together too often. On one side sit the global systems integrators – Infosys, Cognizant, HCLTech – built for multi-year, multi-application transformation programs with hundreds of consultants on a single account. On the other side sit focused engineering shops that specialize in one or two stacks and take on a single platform or a cluster of related systems at a time.
For a mid-market fintech or legal tech company with one aging platform, the integrator model can be overkill: the governance overhead alone can outweigh the migration work. A leaner partner that has done .NET Framework-to-modern-.NET or AngularJS-to-Angular migrations dozens of times tends to move faster on a single-system project, because there’s less program management layered on top of the actual engineering.
Neither model is wrong. The mismatch happens when a company with one legacy platform hires a firm built for thousand-application portfolios, or when a company with a dozen interconnected legacy systems hires a boutique shop without the bench to staff it. Matching scope to firm size matters as much as matching tech stack expertise.
1. Infosys
Infosys runs modernization as one track inside a much larger digital transformation practice, built to support the kind of multi-year, multi-application programs that global enterprises sign for years at a stretch. The firm’s legacy-to-cloud work spans mainframe, ERP, and custom application estates across banking, insurance, and manufacturing clients worldwide. That breadth is real: few firms can staff a thousand-application replatforming program the way Infosys can.
Clutch shows Infosys at 5/5 across 5 reviews, a strong signal though a thin sample next to its overall client base.
Pricing sits at the premium end and runs on a custom-quote basis, consistent with an engagement model built around large, multi-year statements of work.
Ideal for: large enterprises running portfolio-wide modernization programs across dozens of interconnected applications.
2. ScienceSoft
What sets ScienceSoft apart is sheer published volume: the company’s case study library covers healthcare, fintech, and manufacturing modernization projects with specific before-and-after detail, not just industry name-drops. It has built a reputation on legacy system audits that precede any migration work, mapping technical debt before committing to a rebuild path.
Clutch puts ScienceSoft at 4.8/5 across 43 reviews, one of the deeper review samples among mid-market modernization firms.
Pricing lands mid-market and is quoted per project, which tracks with a firm sized for serious but not enterprise-scale modernization work.
Ideal for: mid-market companies wanting a documented, audit-first approach before any code gets touched.
3. Leobit
Leobit works modernization projects across Microsoft and JavaScript stacks, with more than 70 completed engagements that include 15-plus full platform migrations – .NET Framework to modern .NET, ASP.NET Web Forms to ASP.NET Core and Angular, AngularJS to Angular, Xamarin to .NET MAUI, and monolith-to-microservices moves, alongside WCF, WinForms, DevExpress, VB.NET, and Delphi codebases. For companies weighing which of the best software modernization companies can handle a live system without downtime, Leobit’s model is built around exactly that: modernizing module by module while the platform keeps running.
One proof point stands out. A legal case management platform first built in the 1990s was moved from ASP.NET Web Forms to Angular one module at a time, all while it kept serving government and legal users without an outage window. That’s not a lab demo; it’s a production migration under real load.
The process starts before any code changes: system and codebase analysis, then architecture redesign, so the team decides what to refactor, re-platform, or rebuild rather than defaulting to a full rewrite. Delivery runs through 78 Microsoft-certified engineers with more than 100 cloud projects across Azure, AWS, and GCP.
On Clutch, Leobit holds a 5/5 rating across 66 reviews.
Pricing is mid-range and quoted per engagement, positioned between boutique shops and the premium systems integrators.
Leobit’s scope is Microsoft, JavaScript, and mobile codebases specifically – there’s no mainframe or COBOL practice, so teams with mainframe estates need a different kind of partner. For the .NET, Angular, Xamarin, and Delphi world this article is written for, that focus is exactly the point.
Ideal for: product owners and engineering leads modernizing a live .NET, Angular, or Delphi platform in stages, without a roadmap freeze.
4. Cognizant
Cognizant’s modernization practice leans on decades of enterprise application management experience in insurance, healthcare payer systems, and banking core platforms. The firm pairs modernization work with ongoing managed services, so a legacy replatforming project can roll straight into long-term application support without switching vendors.
That combination suits companies that want one partner across both the migration and the years of maintenance after it. Cognizant’s case studies tend to cite industry and outcome rather than client name, consistent with how large integrators typically publish under NDA-heavy enterprise contracts.
Pricing runs at the premium tier on a custom-quote basis, in line with its position as a full-service enterprise IT partner rather than a specialist shop.
Ideal for: enterprises that want modernization bundled with long-term managed application support from a single vendor.
5. SoftServe
SoftServe built its name on deep engineering benches in cloud architecture and data platforms, with modernization work that frequently pairs legacy replatforming with a broader cloud migration to Azure or AWS. The firm publishes technical detail in its engineering blog that goes beyond marketing copy, covering specific patterns for breaking apart monoliths and modernizing data layers alongside application code.
Clutch lists SoftServe at 4.8/5 across 4 reviews, a small but positive sample.
Pricing sits mid-market and is quoted per project, reflecting a firm sized between boutique specialists and the largest global integrators. Teams whose primary need is cloud migration alongside application modernization, rather than one without the other, tend to find the fit here.
Ideal for: companies pairing application modernization with a parallel move to a public cloud platform.
6. HCLTech
HCLTech operates at global-integrator scale, with modernization services woven into a broader portfolio spanning infrastructure management, product engineering, and enterprise application services. Its legacy modernization case studies tend to describe large financial services and telecom clients undertaking multi-system transformation, often running several years end to end.
That scale is the whole story: HCLTech is built for organizations with sprawling legacy estates, not a single platform needing a focused rebuild. Engagement models mirror that scope, typically structured as long-term programs with dedicated account teams rather than fixed-scope projects.
Pricing sits at the premium end on a custom-quote basis, matching the scale of program it’s built to run.
Ideal for: large organizations with dozens of legacy systems needing a single vendor to manage a years-long transformation program.
How to Choose Without Betting the Roadmap on the Wrong Partner
Group these six by what they’re actually built to do. Infosys, Cognizant, and HCLTech are scale plays: built for organizations running multi-year, multi-application transformation programs where one vendor manages dozens of systems and years of roadmap. ScienceSoft and SoftServe sit in the middle, sized for serious mid-market modernization with strong published evidence of process and technical depth, but without the massive program-management overhead of the global integrators. Leobit fits the same middle tier but leans further into the staged, module-by-module approach specifically for companies with one aging platform that can’t afford downtime or a roadmap freeze during the transition.
None of these is the automatic right answer. A company with fifty interconnected legacy systems and a five-year transformation budget needs different governance than one with a single ASP.NET Web Forms platform serving paying customers today.
| Company | Best for | Pricing |
| Infosys | Enterprise-wide, multi-application transformation programs | Premium, custom-quote |
| ScienceSoft | Mid-market modernization with documented audit-first process | Mid-range, per-project |
| Leobit | Staged modernization of a live .NET, Angular, or Delphi platform | Mid-range, per-engagement |
| Cognizant | Modernization bundled with long-term managed support | Premium, custom-quote |
| SoftServe | Modernization paired with a parallel cloud migration | Mid-range, per-project |
| HCLTech | Years-long transformation across dozens of legacy systems | Premium, custom-quote |
The right pick is the one whose scale matches the actual system in front of you, not the one with the biggest name on the deck.
Frequently Asked Questions
How much do the best software modernization companies typically cost?
Most firms in this space quote per project or per engagement rather than publishing rates, since scope varies heavily by codebase size and migration complexity. Mid-market specialists tend to price below global integrators, which run premium, custom-quoted programs built for multi-year scope.
How do I choose the best software modernization company for a live production system?
Prioritize firms with published proof of modernizing systems without downtime, module by module, over ones that only describe full rewrites. Ask how they assess the existing codebase before proposing an approach, and check whether their team has handled your specific legacy stack before.
What services do best software modernization companies usually provide?
Typical scope includes codebase and architecture assessment, incremental refactoring or re-platforming, cloud migration, and framework upgrades such as moving from Web Forms to modern Angular or .NET. Many also offer ongoing support once the migration phases are complete.
