Leading Application Modernization Firms in 2025

We evaluated firms on: 

• Expertise: Proven track record in legacy modernization, cloud-native development, and microservices.
• Client Experience: Strong reviews and case studies demonstrating reliability and business impact.
• Team Skills: Certified engineers, architects, and project managers with industry-specific knowledge.
• Affordability: Transparent pricing and solid value for cost.
• Flexibility: Ability to adapt to changing project needs and offer multiple engagement models.

Code District specializes in turning brittle legacy systems into cloud-ready, API-first applications. Instead of lift-and-shift, they focus on re-architecture, performance tuning, and UX streamlining so modernized apps are faster, safer, and easier to maintain. Clients call out their discovery process – mapping business goals to technical decisions – so modernization delivers measurable impact, not just new code.

The company has earned a spot on the Inc. 5000 list of the Fastest-Growing Companies in the US for 2025. Its commitment to quality and security is backed by ISO 9001 and ISO 27001 certifications. Code District is also a proud AWS Partner and an active member of the Forbes Business Council, further underscoring its credibility as a trusted modernization partner.

Services They Offer

• Application modernization 
• Custom software development
• Cloud engineering & migration
• AI and data integration
  

Company Overview

• Min Project Size: $10,000+
• Hourly Rate: $25 – $49 / hr
• Employees: 250 – 999
• Founded: 2017

Accenture brings reputable modernization at enterprise scale, using accelerators (e.g., discovery tooling, automation frameworks) to decompose monoliths and stand up cloud-native services with guardrails. Their global delivery model fits complex estates – mainframes, ERPs, custom apps – and tight compliance regimes.

Accenture often pairs modernization with operating-model changes: CI/CD, platform engineering, and FinOps. For large portfolios with intertwined systems and strict SLAs, they’re one of the safest bets among application modernization firms.

Services They Offer

• Application modernization
• Cloud migration & platform engineering
• Digital transformation consulting
  

Company Overview

• Employees: 500,000+
• Founded: 1989
• HQ: Dublin, Ireland

Cognizant’s “factory” approach standardizes assessment, refactoring, API enablement, and migration – ideal for organizations modernizing dozens or hundreds of apps. They focus on reducing risk while improving agility, often starting with customer-facing workloads for quick ROI.

With deep domain teams in BFSI, healthcare, and retail, Cognizant threads regulatory needs through design and delivery. If you need consistent execution across a big estate, this is one of the application modernization firms built for it.

Services They Offer

• Application modernization & re-platforming
• Cloud-native development
• IT strategy & consulting

Company Overview

• Employees: 300,000+
• Founded: 1994
• HQ: Teaneck, NJ, USA

IBM leans on hybrid cloud, Red Hat OpenShift, and AI-assisted code analysis to modernize critical systems without sacrificing stability. They’re strong where security and governance matter most – financial services, government, and healthcare.

IBM’s method: containerize where possible, refactor where necessary, and automate regression testing and policy checks. Among application modernization firms, few match IBM’s combo of infrastructure, software, and services under one roof.

Services They Offer

• Application re-platforming & refactoring
• Hybrid/multi-cloud migration
• AI-driven code & test optimization

Company Overview

• Employees: 350,000+
• Founded: 1911
• HQ: Armonk, NY, USA

N-iX helps enterprises move from on-prem monoliths to scalable, cloud-native stacks. Their playbook pairs architecture redesign (microservices, messaging) with practical cost controls, so you get resilience without runaway bills.

They’re flexible on engagement – project teams or team extension—and strong on data platforms and integrations. For organizations seeking cost-effective European engineering, N-iX is a reliable addition to any shortlist of application modernization firms.

Services They Offer

• Cloud transformation & DevOps
• Application re-architecture
• Dedicated development teams

Company Overview

• Min Project Size: $100,000+
• Hourly Rate: $50 – $99 / hr
• Employees: 2,400+
• Founded: 2002

Software Mind replaces brittle monoliths with modular service layers and upgrades front ends to modern UX frameworks. Their nearshore model (EU/LATAM) gives you senior engineers in overlapping time zones at competitive rates.

They blend modernization with product thinking—prioritizing features that unlock business value first, then iterating. For teams that want architectural upgrades and UX gains together, this is one of the application modernization firms to consider.

Services They Offer

• Application re-architecture & rewriting
• Cloud consulting & migration
• UX/UI redesign

Company Overview

• Min Project Size: $50,000+
• Hourly Rate: $50 – $99 / hr
• Employees: 1,600+
• Founded: 1999

Icreon modernizes back-end systems while elevating customer experience – handy for commerce and subscription platforms where UX and performance directly impact revenue. Expect thorough assessment, a crisp roadmap, and tight alignment to KPIs.

Their cross-functional squads (strategy, design, engineering) ensure front-end, API, and data work land together. If modernization success will be judged by CX metrics, Icreon is a strong entrant among application modernization firms.

Services They Offer

• Application modernization
• CX strategy & design
• E-commerce/platform modernization

Company Overview

• Min Project Size: $50,000+\
• Hourly Rate: $100 – $149 / hr
• Employees: 400+\
• Founded: 2000

Infopulse tackles mission-critical workloads with sector-specific blueprints (telecom, finance, manufacturing). They couple re-engineering with managed services so your modernized apps stay healthy post-go-live.

Strengths include ERP/CRM modernization, secure cloud migration, and steady-state operations. If you need a partner to transform and then run the stack, Infopulse is one of the more complete application modernization firms.

Services They Offer

• Application modernization & re-engineering
• Cloud migration & DevOps
• Managed IT & consulting

Company Overview

• Min Project Size: $50,000+
• Hourly Rate: $50 – $99 / hr
• Employees: 2,000+
• Founded: 1991

Endava modernizes at enterprise scale with agile delivery and platform thinking. They inventory portfolios, prioritize by value/risk, and ship increments – so benefits accrue while deeper refactors continue.

They’re strong in payments, retail, and media – industries where uptime and latency matter. For global programs with many stakeholders, Endava is one of the application modernization firms built for collaboration.

Services They Offer

• Application modernization & re-architecture
• Digital engineering
• Application management & DevOps

Company Overview

• Employees: 10,000+
• Founded: 2000
• HQ: London, UK

Symphony Solutions brings boutique attention to cloud migrations and continuous delivery. They pair engineering with agile coaching, so teams adopt modern practices alongside modern stacks.

Expect tight team integration, fast feedback loops, and long-term support. If you want hands-on help and culture change, this boutique stands out among application modernization firms.

Services They Offer

• Application modernization & cloud migration
• DevOps & agile enablement
• Product development & UX

Company Overview

• Min Project Size: $25,000+
• Hourly Rate: $50 – $99 / hr
• Employees: 550+
• Founded: 2009

Modernizing legacy applications is no longer optional – it’s the foundation for agility, scalability, and growth in 2025. The firms in this list have the expertise to help organizations reduce technical debt, unlock cloud capabilities, and future-proof their software. U.S. leaders like Code District, Cognizant, and IBM, along with global partners such as N-iX and Symphony Solutions, show what’s possible when modernization is done right.

Among them, Code District stands out for its balance of technical depth, affordability, and client-focused delivery. 

If you’re ready to take the next step in modernizing your applications, book a free consultation today!