Product Modernization

Legacy systems are usually load-bearing. They are also usually running critical operations on unsupported dependencies, understood by fewer people every year. Modernisation is risk management as much as engineering: the goal is to reduce the danger without an all-at-once rewrite, because big-bang replacements are how companies lose a year and their appetite for the project.

What this covers

Move systems off ageing foundations incrementally, keeping the business running throughout.

• Codebase and architecture assessment
• Dependency and framework upgrades
• Incremental replacement and strangler patterns
• Database migration and schema modernisation
• Cloud migration and containerisation
• Test coverage for untested code
• Documentation and knowledge recovery

Where modernisation usually goes wrong

The big-bang rewrite. Rebuilding everything in parallel means a long period with two systems, no new features and a risky cutover. It is the most commonly attempted approach and the most commonly abandoned.

No tests before changes. Refactoring untested code is guesswork. Characterisation tests come first, even when they feel like a detour.

Losing undocumented behaviour. Old systems accumulate business rules nobody wrote down. Rewrites that miss them break processes in ways that surface months later.

Modernising the wrong thing. The oldest component is not always the riskiest. Effort should follow business risk, not technical distaste.

How we build it

1. Assess. Codebase review, dependency audit and risk mapping — what actually threatens the business, ranked honestly.
2. Stabilise. Characterisation tests around critical paths and urgent security fixes, so later changes are safe to make.
3. Replace incrementally. New functionality built alongside the old system, with traffic moved across piece by piece and a rollback available at every step.
4. Decommission. Retire old components only once their replacements have proven themselves in production.

Technologies we work with

• Legacy: older PHP, .NET, Java, ColdFusion, classic ASP
• Target: Node.js, Python, Go, modern PHP, React
• Data: PostgreSQL, MySQL, MongoDB, migration tooling
• Infrastructure: AWS, GCP, Azure, Docker, Kubernetes
• Practice: automated testing, CI/CD, observability

What you get

• An honest, prioritised assessment of your real risks
• Test coverage where there was none
• Incremental delivery with rollback at every stage
• Recovered documentation of undocumented behaviour
• A system your team can maintain and hire for

Frequently asked questions

Should we rewrite or modernise?

Almost always modernise. A full rewrite makes sense when the existing system genuinely cannot support the business direction, and even then it is best done incrementally behind a stable interface.

Can you work with technology nobody here understands any more?

Usually. Part of the assessment is reading the system and reconstructing what it does, which is often the most valuable output on its own — several clients have stopped after the assessment because it told them what they needed to know.

Will the business be disrupted?

Incremental replacement is specifically designed to avoid that. Changes go out in small pieces with rollback available, rather than one high-risk cutover weekend.

How long does modernisation take?

It is ongoing rather than a project with an end date, which is why we sequence by risk. You get meaningful risk reduction early instead of waiting for a distant finish line.

How we start

Every engagement starts with a short, fixed-scope conversation. You leave with a plan and a price whether or not you continue with us.