Engineering Notes
Reflections and patterns discovered while building frontend systems.
The feed didn't tell me which way the bus was going
A real-time feed is only half the data. Two silent mistakes about missing values, and the small timetable join that fixed both.
What counts as late is a setting
A live bus map that flagged 377 incidents on a Friday afternoon. The fix wasn't a better algorithm; it was admitting that every alert rule is an opinion, and deciding whose.
Measuring an AI assistant instead of guessing
Twenty-one real questions exposed plausible answers built on the wrong evidence. A repeatable test showed which fixes worked—and which diagnoses were wrong.
When the canonical model becomes the interface
Why a technically correct interchange model can become the wrong contract for a human-facing workflow.
Map Core Architecture
Building a reusable geospatial foundation for operational transport systems.
MobX Architecture Patterns
Structuring long-lived frontend state for complex operational systems.
Map Data Contracts
Designing resilient interfaces between frontend mapping components and backend geospatial services.