S7 · Scoped after an architecture or codebase review
Technical Recovery / Refactor
Stabilise, refactor or replatform a system without stopping delivery by proving behavioural equivalence before switching over.
Constructed handover specimen · not a client finding
A comparison receipt with an explicit limit
- Trigger
- Which existing behaviour must the replacement preserve?
- What you receive
- The specimen receipt records input, old result, new result, comparison rule and implementation versions for each observation.
- Decision supported
- Resolve any difference as a defect or an authorised behaviour change; keep rollback available. Ember’s separate public receipt covers 2,510 observations with zero differences inside its measured boundary.
Who it is for
Teams whose system must change without losing the behaviour people already depend on.
- The work
- We observe the current system, turn important behaviour into an executable comparison boundary, land the replacement behind it and keep rollback available until divergence is closed.
- The boundary
- The equivalence boundary is agreed up front. Unrecorded legacy behaviour discovered during the work is made visible rather than silently treated as either correct or disposable.
What you receive
An executable equivalence harness, completed refactor and tested rollback path.
- Duration
- Scoped after an architecture or codebase review
- Price (GBP)
- from £25,000 or £1,400/day
- Commercial shape
- scoped fixed price or day rate