EuroSciPy 2026

Your simulation is 40 hours into a 48-hour SLURM allocation and it has stopped making progress. You can't restart it, and you didn't instrument it. Until recently, Python's official answer was "you should have thought about that earlier." That answer has changed.

Python 3.14 and 3.15 quietly shipped the biggest upgrade to observability in the language's history: a safe, supported way to attach a debugger to any live Python process (pdb -p), and Tachyon, a sampling profiler in the standard library that attaches to a running process with virtually zero overhead and can tell you -- among other things -- which thread is hogging the GIL, at up to a million samples per second.

But scientific Python is observability's hardest case: long-running, thread-heavy, mostly native code underneath, and increasingly on the GPU. I'll demo what the new tools do on live processes, but will also be honest about where they still go dark today -- native frames, free-threaded builds, GPU timelines -- and lay out a plan for Python 3.16, which you can help shape as well.