Problem
Checkout leakage and broken course discovery were killing retention.
Lumina
Learning platform for professionals.
The solution
Six independently shippable workstreams: search, retention, payments, frontend performance, grading reliability.
Approach
Structured the rebuild as six independently shippable workstreams with clear interface boundaries, so no single risky rewrite blocked delivery
Built hybrid BM25 + pgvector search directly in Postgres instead of adding an external search service the scale didn't justify
Migrated Svelte 4 to 5 surface-by-surface behind feature flags — every component reversible without a deploy
Fixed grading disputes by moving from floating-point to integer arithmetic with write serialization
Next case
Revrock
Musicians planned tours without knowing where the audience or money was. Built routing and revenue planning around real demand.