Notes
Short essays on how we build — design choices, tradeoffs, and the reasoning behind the work.
Working notes from the collective. Design decisions we’ve thought about long enough to write down, tradeoffs we’ve made on purpose, and the occasional post-mortem when something taught us more than it cost.
No cadence, no editorial calendar. A note appears when there’s something worth saying.
- Learning-first
Why we built a Kafka-shaped broker from scratch — and what "learning-first" actually means as a design constraint.
- One event, two consumers
Why the metering plane for paid tiers rides the audit stream we already had — and what we chose not to build.
- Tools, not endpoints
What building three MCP servers taught us about designing for a probabilistic caller.
- When the caller is a coin flip
How we test MCP servers whose caller is an LLM — and what we deliberately didn't build.