We ran a data backfill on 140,000 subscription records while the app was live. Three weeks later, 1,800 customers had the wrong renewal date. The script looked fine. The bug was in the timing.
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Hello, I'm Luke
Applied AI architecture, agent harnesses, and notes from getting AI systems into production.
Latest Posts
- On-call never shows up in exit interviews. But across half a dozen consulting engagements, I've watched it quietly hollow out engineering teams. The pattern is always the same, and it's always fixable.
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- Every 30 minutes, the auth server spiked to 100% CPU and shed requests. The pattern was so regular you could set a watch by it. Turned out every user's JWT expired at the same time.
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- Every deploy dropped a handful of requests. The service had a SIGTERM handler. It just didn't do what anyone thought it did.
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- A client's React class-to-hooks migration had been "90% complete" for fourteen months. The last 10% contained every hard problem the team had been avoiding. Gradual migrations don't fail at the start — they fail when nobody decides to finish.
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