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Software · Platform

Application modernization without a risky big-bang rewrite.

We assess legacy applications, decide part by part whether to keep, refactor, replatform or rebuild, and migrate in controlled stages while the business keeps running.

Discuss a legacy system
What we deliver
  • Application assessment
  • Modernization roadmap
  • Safety net
  • Incremental migration
  • Data migration
  • Decommissioning plan
Tools & platforms
.NET and JavaNode.js and TypeScriptPostgresDocker and KubernetesAWS, Azure and Google Cloud

Where this helps

A critical system on outdated technology
The application runs core operations on an unsupported framework or database. Security patches are no longer available, and finding people who know the stack is getting harder.
Every change takes months
The codebase is large, untested and tightly coupled. Simple feature requests turn into long projects, and the business works around the system instead.
A rewrite was attempted and stalled
A previous full rewrite ran over time and budget, the old system kept changing underneath it and the new one never reached feature parity.

What we deliver

01
Application assessment
A review of code, architecture, dependencies, data, integrations and operational risk, with a map of which parts matter most to the business.
02
Modernization roadmap
A staged plan deciding, component by component, whether to retain, refactor, replatform, rebuild or retire — with sequencing and dependencies.
03
Safety net
Characterization tests, monitoring and a deployment pipeline around the existing system, so changes can be made without guessing.
04
Incremental migration
New components built alongside the old, with traffic and data moved over piece by piece.
05
Data migration
Mapping, cleansing and migration of data with reconciliation checks, and a rollback plan for each step.
06
Decommissioning plan
A controlled retirement of legacy components once their replacements are proven, including archival of data that must be kept.

How it works

  1. 01

    Assess

    We study the existing system, talk to the people who use and maintain it and identify the highest-risk and highest-value areas.

  2. 02

    Stabilize

    Tests, monitoring and automated deployment go around the current system first.

  3. 03

    Plan the stages

    We agree the order of migration, starting where value is high and dependencies are manageable.

  4. 04

    Migrate incrementally

    Each component is replaced, verified in parallel with the old one and switched over, one at a time.

  5. 05

    Retire

    Legacy components are switched off only after the replacement has run reliably in production.

Design decisions we make with you

  • Refactor, replatform or rebuild

    Moving to new infrastructure with minimal code change is fastest; refactoring improves structure in place; rebuilding suits parts where the logic is well understood and the code is not worth saving.

  • Incremental replacement

    We route traffic through a layer that can send each function to old or new code, so replacement happens gradually rather than on one cutover date.

  • Data first or code first

    Where the data model is the constraint, migrating data structures comes first. Otherwise we start with the application layer and keep the database stable.

  • Business continuity

    Each stage has a rollback plan, and cutover timing is agreed with the teams who depend on the system.

Applications

Core systems in financial services
Moving policy, account or transaction systems onto supported platforms without interrupting operations.
Manufacturing and plant systems
Replacing aging desktop and on-premises applications with web-based tools connected to modern data platforms.
Public sector services
Modernizing case management and citizen-facing systems with careful data migration.
Preparing systems for AI
Exposing data and functions from legacy systems through APIs so AI applications can use them safely.

Related capabilities

Solutions
Services

Questions buyers ask

Rarely all at once. Full rewrites carry high risk because the old system keeps changing and hidden business rules are lost. We usually replace the system in stages, rebuilding only where it is clearly justified.

AI coding tools help analyze and document legacy code, draft tests and translate code — with engineers reviewing every change. See software engineering AI.

We plan stages to avoid it, running old and new components in parallel and switching over in small steps. Where a short cutover window is unavoidable, it is scheduled with the affected teams.

Discuss this capability with an engineer.

Tell us about the workflow or product. We reply with questions, a suggested first step and who would work on it.

Discuss a legacy system