🤖 Designing a robot that talks with kids
How a robot that talked with kids worked: the body, the parts, the wiring, the software and the cloud, and the reasons behind each choice.
#System-Design
🚂 Temporal — Under the Hood
Every SQL statement a Temporal workflow runs against Postgres, and why each one exists. Then Absurd, a 5-table durable-execution engine in one SQL file, does the same job with about a fifth of the statements and 20× the throughput.
💸 1B Payments/Day - TigerBeetle & PostgreSQL
Napkin math and reproducible benchmarks for a ledger at a billion payments a day: TigerBeetle vs PostgreSQL, traced with eBPF down to the io_uring and fsync calls.
🪲 The Tiger Style
A repost of TigerBeetle's coding guide. It ranks safety, then performance, then developer experience, and gives rules for assertions, limits, static memory, batching, and naming.
♥️ System Design - Tinder
How to design a location-based dating app for 75M daily users: derive the load, precompute each user's deck, find nearby people with geohash cells, check matches without races, and never lose the first message.