Case study
Leading an identity migration, plan-first
De-risking a sprawling change by freezing the plan before touching code.
migration doc
Artifact
cross-service
Scope
ordered
Execution
Situation
A significant migration of identity functionality and table design was needed across services — one of the largest efforts I've driven.
Task
De-risk a large change with many moving parts.
Action
I first drove out a written migration plan and design document — prerequisites, sequencing, and table design — got it right, then implemented against it, deliberately keeping the plan file frozen during implementation so it stayed the source of truth.
Throughout, I used git diff to define the exact blast radius and targeted tests to precisely what changed, leaning on the compiler and the test suite as the safety net for wide changes.
Result
- Turned a sprawling migration into an ordered, reviewable execution.
- Established plan-first as my default for large or risky work.
- Kept the change auditable — every step traceable back to the frozen plan.