Before a large rewrite, a written assessment defines what is in scope, what can go wrong, and which risks the team is willing to take. Without that, people can agree on the goal while assuming different constraints.
What an assessment should answer
- Interfaces — which APIs and integration points are in scope, and which legacy seams are explicitly out of scope for this phase.
- Security and trust boundaries — where authentication, authorization, and data residency assumptions change if the design ships.
- Latency and operations — what gets worse under load, and which monitoring needs to exist on day one rather than later.
Why it is not a design doc
An assessment can conclude with “do not proceed without X” or “consolidate these two systems first.” That can expose blockers before implementation commits the team to a direction.
Related work context
During a fintech platform period, this assessment covered core-banking evaluation and user-management consolidation before gateway and deployment work accelerated. The gateway case study records the implementation that followed.