The original developers have left. The documentation is a wiki page from 2014 and a comment that says “do not touch”. Leadership wants a rewrite. The operations team wants nothing to break before Diwali. This is the usual modernization brief.
AI helps in specific jobs. It can map a codebase you no longer understand: modules, dependencies, the implicit business rules hiding in if-statements. It can draft architecture notes and API contracts. It can generate characterization tests that lock current behaviour before you change it. It can suggest translations of a module into a modern service — which an engineer then reviews as if a junior wrote it, because that is what it is.
What fails: pasting an entire monolith into a prompt and asking for microservices. Shipping generated code without tests. Pretending a rewrite is “accelerated” when you have not wrapped the live system. The strangler pattern is still the grown-up approach. Wrap what you need as APIs, replace the highest-value modules first, keep the rest running.
We work under NDA, and we can work inside your environment so source never leaves it. Every change goes through code review, automated tests and a staged release. AI is in the loop. It is not the owner of the loop.
Bring a system overview, not a wish for a miracle. We will return a risk map, a phased plan and an estimate that assumes engineers still have to be awake.