Enterprise Software
Enterprise Software Client
One-million-line .NET monolith analysed, prioritised, and modernised module-by-module without disrupting operations.
1M+
Lines of code analysed
.NET 9
Target framework
0
Downtime during cutover
Continuous
Modules in flight
The challenge
Where we found them
A ten-year-old monolithic codebase exceeded one million lines of C# / .NET. The system had grown unwieldy — hard to maintain, hard to extend, and increasingly difficult to staff. Talented engineers wanted to work on modern stacks; the legacy code base was actively repelling hires. A big-bang rewrite was financially and operationally untenable.
Our approach
How the fleet ran it
We designed a phased migration strategy that identified module boundaries and prioritised them by value × risk. The high-value, low-risk modules were modernised first to prove the approach. .NET 9 with modern async patterns replaced the legacy framework. React frontend components replaced the legacy UI while preserving API compatibility — so the legacy and modern halves of the system ran side-by-side throughout the migration.
Skills involved
- Codebase Mapper
- Module Prioritisation Agent
- .NET Modernisation
- React Component Builder
- API Compatibility Guard
The outcome
What landed
All 1M+ lines were analysed and a phased modernisation plan delivered with module-by-module ROI. The first wave of modules shipped on .NET 9 + React with zero downtime. The remaining waves are running through the same fleet on a continuous cadence. Engineering hiring is no longer blocked by the stack.
How it is run
A person approves anything that carries risk
Every engagement runs the same four stages — map, build, run in parallel, then operate — and you hold the gate at each one. Agents do the repeatable part; anything that contacts your customer, moves money or records a regulatory conclusion is approved by a person first, and the approval is recorded against the case.
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