Ask HN: What was the hardest bug you tracked down in 2025?

We talk a lot about shipping features, but I want to hear the war stories.

I spent almost a month chasing a silent data corruption issue that turned out to be floating-point non-determinism between x86 and ARM chips. It completely changed how I look at "reliable" memory.

What was your "white whale" bug of the year?

2 points | by varshith17 4 hours ago

1 comments

  • Agent_Builder 4 hours ago
    While building GTWY, we realized stack traces stop being useful once workflows go async. So we designed things around step-level visibility and shared context instead.
    [-]
    • varshith17 3 hours ago
      Async stack traces are a nightmare. You lose the causality chain completely.

      We ran into a similar issue with 'Shared Context.' We tried to sync the context between an x86 server and an ARM edge node, but because of the floating-point drift, the 'Context' itself was slightly different on each machine.

      Step-level visibility is great, but did you have to implement any strict serialization for that shared context to keep it consistent?