rio tanaka · staff systems engineer · portland, oregon · utc-8
rio@caret.exampleBuilds from the last seven years, described as the problems they were, not the slides they became. Stacks listed as used, not as aspired to.
A payments platform was dropping webhooks under backpressure, silently, at the worst possible p99. I rebuilt delivery as an append-only pipeline: every event journaled before ack, retries with jittered backoff and idempotency keys, and a dead-letter queue that humans actually read. Fourteen months in production, forty million events a day, zero silent drops.
Six hundred engineers, one monorepo, forty-minute builds. Coldstart was two years of unglamorous work: remote build caching, test sharding by historical timing, and deleting the flaky tests nobody would admit to owning. Median CI run went from 41 minutes to 6, and the Friday deploy stopped being a dare.
Three hundred grocery stores, each with a Linux box in the back room behind someone else's firewall. Driftwatch keeps that fleet converged: a 4 MB agent, delta updates over store Wi-Fi that drops nightly, and a control plane that assumes every box is offline half the time. IT store visits went from weekly to almost never.
The billing monolith computed money in floats, and nobody could say why the totals drifted. Ledgerline is the double-entry ledger I extracted from it: integer cents, immutable entries, and a nightly reconciler that refuses to close until every account balances. Finance retired their shadow spreadsheet. That was the whole KPI.
What has my attention this season. Rewritten when the weather changes, like a good changelog.
+ 38 earlier entries in the archive, available on request.
Rio Tanaka started in a university basement, learning Unix by breaking the mail server and staying late to fix it. Since then: a freight-payments platform where the webhooks never slept, a grocery-logistics fleet with a computer in every store's back room, and a developer-tools team where the build queue was the product. Three very different companies, one recurring job description: make it boring, keep it honest, write it down.
Away from the terminal, Rio is in Portland restoring a 1974 stereo receiver, over-engineering drip irrigation for six tomato plants, and losing gracefully at Tuesday-night go club. The keyboard is a buckling-spring relic from 2009. The coffee is a pour-over. The pager, these days, mostly sleeps.
Consulting, staff-plus roles, conference talks, or a good argument about retries. Plain email, answered within a day. If it's urgent, it should probably be a postmortem instead.
rio@caret.example