One Line of Code Froze My Entire FastAPI Server
A debugging war-story about async def, a blocking call, and the event-loop trap that makes a fast framework crawl.
Oct 17, 20268 min read1 reactions0 comments
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Oct 17, 2026FP16 Quantization Quality Loss: We Blamed the Architecture, the Bug Was One Overflowed Tensor
Our fp16 quantization post-mortem was wrong in the expensive direction: it told anyone with a...
Oct 17, 202610 min read0 reactions0 comments
Shrinker Debugfs Shows Which Kernel Cache Holds Memory
The shrinker debugfs interface has shipped since Linux 6.0 and is off by default. It shows exactly how many reclaimable objects each kernel cache holds.
Oct 17, 202613 min read0 reactions0 comments
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Oct 17, 2026The Stop Button Worked Once: Debugging a Reused AbortController in a Streaming Chat
Last week a teammate sent me a two-line message at the end of the day: "Stop works the first time....
Oct 17, 20266 min read0 reactions0 comments
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Oct 16, 2026The Illusion of Progress: how a typo in my custom mutator sent my fuzzer into the wrong parser
A question up front — I'll answer it at the end: when did you last verify that your fuzzer is...
Oct 16, 20267 min read0 reactions0 comments
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Oct 16, 2026Your fetch failed, your code wrote an empty array, and now your tests assert a lie
A truncated HTTP body became an empty list, the empty list became a test fixture, and the fixture became a permanent false fact. Three cheap design rules that make "empty result" impossible to confuse with "no result".
Oct 16, 20266 min read0 reactions0 comments
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Oct 17, 202648-Hour Field Notes: It Passed Locally and Died Remotely — Eight Environment Facts I Now Diff First
Have you ever shipped a script that ran clean on your laptop and then failed on a remote box with...
Oct 17, 20268 min read0 reactions0 comments
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Oct 16, 2026The flaky test that was a tenant-isolation bug
A database test in our suite failed about one run in eight. Here is the full path from symptom to...
Oct 16, 20263 min read0 reactions0 comments
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Oct 17, 2026Go Typing Indicator Debugging: 5 Checks for Missing Stop Event Expiry
Short answer: Treat every typing-start signal as a renewable client-side lease, expire it locally,...
Oct 17, 20266 min read0 reactions0 comments
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Oct 16, 202648-Hour Field Notes: I Benchmarked a Cold Endpoint and Called It Compute
Why did the median look fine while the tail looked like a different machine? I spent the...
Oct 16, 20266 min read0 reactions1 comments
My URL-to-Markdown converter chased a redirect chain into a consent wall — and learned to stop early
Had a real debugging session last week on the URL-to-Markdown fetch pipeline. A user fed it a link to...
Oct 16, 20262 min read0 reactions0 comments
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Oct 16, 2026n8n error handling: capture failures before adding retries
An n8n workflow can fail mid-run. It writes half its output, times out, and leaves behind an...
Oct 16, 20264 min read0 reactions0 comments