Legacy System Modernisation in Edinburgh

We plan and execute in phases, running old and new systems in parallel during transition. Your users see no service interruption. Each phase is tested thoroughly before cutover. We map data flows first, set up dual-write mechanisms where needed, and retire legacy components only once the new architecture is proven stable and validated against real production workloads.

Data extraction is preceded by a full audit of your current system's structure, data quality, and dependencies. We write custom extraction routines that validate row counts, checksums, and referential integrity at each step. After mapping to the new schema, we run shadow migrations in test environments and compare outputs. Only when we have confidence in completeness and accuracy do we execute on production.

Yes. We often adopt a strangler pattern, building new microservices alongside the legacy monolith and gradually routing traffic to them. Old functionality stays live until new features are proven. This reduces risk and lets you go live incrementally. It also gives you room to make business decisions about which parts to retire or rearchitect without forcing a big bang.

Database modernisation is rarely a single lift-and-shift. We often move from monolithic databases to domain-driven data models, sometimes splitting into multiple databases. We maintain referential integrity throughout, use event sourcing or changelog triggers to keep data in sync during transition, and test all queries and reports against the new schema before full migration. Legacy reports are rewritten to work against the new database structure.

We reverse-engineer the system through code analysis, tracing data flows, and running tests to understand behaviour. We also interview your team and review any operational or user documentation. This becomes part of our modernisation plan. We don't guess; we validate our understanding by running the legacy system and observing what actually happens. Then we document the new system thoroughly so you avoid this problem again.

Timeline depends on system size, complexity, data volume, and how many parts you're modernising. A smaller application with clear boundaries might take 6-12 months. A large, interconnected monolith with multiple databases could take 18-24 months or longer. We scope the work upfront, break it into phases with clear delivery milestones, and adjust as we learn more about your actual system. You get regular visibility and can go live with individual modules before the whole project ends.