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Discover — mapping a system across a wall of diagrams and plansDiagnose — analyzing dashboards and metrics to pinpoint the problemDesign — wireframes, UI/UX and software development of the solutionDeliver — implementing and delivering the finished productEvolve — continuous improvement and leveling upAn engineer modernizing a legacy system: old mainframe code refactored into a modern architecture

Legacy System Mod­ern­i­za­tion Services

Modernize without betting the business. Our legacy system modernization services migrate old systems in stages, so you cut maintenance cost, close security gaps and connect to modern platforms. Senior nearshore engineers from Monterrey, AI-assisted.

  • Incremental
    No big-bang risk
  • AI-assisted
    Legacy code decoded
  • 17
    Countries served
  • 1,000+
    Projects delivered

Companies that believe in us

What is legacy system modernization?

Legacy system modernization is updating outdated software, platforms and infrastructure, such as mainframes, old codebases and unsupported apps, into modern systems that are easier to maintain and integrate. WeEvolveIT does it in stages from Monterrey, Mexico: we wrap the old system in APIs and migrate piece by piece while the business keeps running.

A modernization map: a legacy monolith wrapped in APIs and connected to modern cloud services and apps
What is a legacy system?
Software a business still relies on that is hard to maintain, change or connect, like a mainframe or an unsupported app.
Why do companies still use legacy systems?
They still work, they hold years of business rules and replacing them feels risky, so teams patch them instead.

Key takeaways

  • Modernize in stages: each piece moves while operations continue.

  • Keep what works: we rebuild only the parts that earn it.

  • Connect legacy to modern: APIs open the old system to new tools today.

  • AI-assisted: AI reads and documents old code faster.

  • From $50 USD/hour: senior nearshore engineers fluent in old stacks and new.

Why modernize

Staying on legacy doesn't save money. It defers risk.

The cost of legacy

  • Scarce talent: the people who know COBOL, old frameworks and your codebase are hard to hire.

  • Security gaps: unsupported software stops getting patches.

  • No integration: modern apps, cloud and AI can't reach a closed system.

  • Rising cost: maintenance, licenses and scarce specialists keep getting pricier.

How WeEvolveIT de-risks it

  • Assess first: a fixed-scope assessment maps dependencies and risks.

  • Wrap, then replace: APIs create a stable boundary to modernize behind.

  • Stages with rollback: each stage is validated and has a way back.

  • AI-assisted: AI helps read, document and translate legacy code.

What we offer

Legacy system modernization services, without the rip-and-replace.

  • Legacy assessment

    We map the system, its dependencies and risks into a costed, staged roadmap.

  • Legacy application modernization

    We rehost, replatform, refactor or rebuild each component, whichever fits it, never as a big-bang rewrite.

  • Integration & APIs

    APIs connect modern apps, cloud and AI to the legacy system while it retires gradually.

  • Cloud migration & support

    We move modernized workloads to the cloud and keep them running.

Modernization approaches

Every component moves the way that fits it.

  • Lift-and-shift

    Rehost

    Same code, new infrastructure. Use it to buy time and get off aging hardware fast.

    Fastest
  • Update in place

    Replatform / Refactor

    Update frameworks, databases and APIs while keeping the business logic. Real gains without a rewrite.

    Balanced
  • Re-architect

    Rebuild

    Re-architect as cloud-native only the components worth the investment.

    Most flexible

The modern stack we modernize onto

Proven, current, and built to last.

  • .NET
  • Python
  • Node.js
  • React
  • PostgreSQL
  • Amazon Web Services
  • Docker
  • Kubernetes

How it works · Our method

Our five-phase method, applied to your modernization.

  1. 01

    Discover

    We map the system, its dependencies and the cost of keeping it as is.

  2. 02

    Diagnose

    We weigh each component's risk and value and pick its path from the 7 R's, or retire it.

  3. 03

    Design

    We design the target architecture, the API boundaries and the order of the stages.

  4. 04

    Deliver

    We wrap, update, migrate the data and validate each stage against milestones, with a rollback plan.

  5. 05

    Evolve

    We retire the old system once nothing depends on it and keep the new one current.

Where we work

US-first, LATAM-rooted, globally proven

  • United States: Monterrey hours (UTC-6) overlap the US business day
  • Mexico & LATAM: HQ in Monterrey
  • Global: clients in 17 countries

Cost & engagement

Scoped to your system, from $50 USD an hour.

Every system is different, so we price once we understand yours. Senior engineering starts at $50 USD/hour, and there are three ways to work with us.

  • Fixed scope · assessment

    Modernization roadmap

    A costed assessment and a staged roadmap, before any code changes.

  • Per stage · milestones

    Modernization project

    Priced and billed against delivered milestones.

  • Per hour · from $50 USD

    Hourly engineering

    Senior engineers for integrations, fixes or a focused modernization sprint.

Why teams choose us for legacy system modernization services

Many legacy modernization services sell a big-bang rewrite. We sell the opposite: an assessment first, then component-by-component modernization behind APIs, so nothing has to stop. The engineers are senior, based in Monterrey and at home in both old and new stacks, and AI speeds up decoding the old code.

FAQ

What teams ask before modernizing.

01What is legacy system modernization?

Legacy system modernization is moving a business off outdated software, platforms or infrastructure without losing what those systems do: assessing the old system, choosing an approach per component, connecting it through APIs and migrating in stages, so it gets cheaper to maintain and easier to change.

02What are the main legacy modernization approaches?

The 7 R's come down to three practical moves: rehost (move it as-is to modern infrastructure, the fastest relief), replatform or refactor (update the stack, keep the business logic) and rebuild (re-architect the parts worth it). We choose per component, never one approach for everything.

03Is it worth replacing a legacy system, or should we modernize it?

It depends on the component, so we decide it in the assessment. A full replacement is slow, costly and risky, and can lose years of business rules. Modernizing keeps what works and updates the rest in stages; we replace only where the numbers justify it.

04How much does it cost to modernize legacy software?

It depends on the size and complexity of the system and how much you rebuild. Senior engineering starts at $50 USD/hour. A fixed-scope assessment comes first and prices each stage of the roadmap before any change, so you can fund the work in phases.

05Can you modernize without replacing the whole system or stopping operations?

Yes. We wrap the legacy system in APIs so new apps and services use it through a stable boundary, then modernize behind it in stages, each validated and with a rollback plan. The old system keeps running and retires gradually, with no all-at-once cutover.

06Can AI help modernize legacy code?

Yes. AI reads and documents legacy code, even COBOL, so we know what the old system really does before changing it, and it speeds up translating that code. Senior engineers lead the work; AI assists but doesn't decide what to keep.

07What does a legacy system modernization services company do, and how do I choose one?

A legacy software modernization company assesses your old systems, picks an approach per component and migrates them in stages. Choose one that starts with an assessment, not a rewrite pitch, and staffs senior engineers. WeEvolveIT works this way, nearshore from Monterrey, Mexico: 1,000+ projects, 17 countries, 15+ years.

Related services

Often paired with modernization

Learn more

From the blog

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Tell us what you run and where it hurts. We'll reply with an assessment, a staged roadmap and a scoped cost.

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