About
The talk
Why Your FastAPI Is Not Fast: A Deep Dive into Hidden Bottlenecks
FastAPI is fast, but only if you use it correctly. The framework gives you the tools and does not protect you from yourself. The talk covers five anti-patterns that quietly erode FastAPI performance. Each one comes with real code, real profiling output, and a measured before-and-after fix, from a reproducible Orders API you can run yourself.
The talk opens with a real-world pattern: a FastAPI service, rewritten from a synchronous Flask predecessor for speed, performed worse under real concurrency. Its single-request benchmarks looked good. Production did not.
| Event | PyCon Hong Kong 2026 |
| Track | Software Engineering & Platforms |
| Length | 30 minutes |
| Slot | Sat 14 Nov 2026, 14:25–14:55 HKT, per the presenter guide. Confirm the time before the day. |
The talk is about what happens inside route handlers and dependencies. Tracing and observability are covered in the neighbouring talk in the same track.
The speaker
Satyam Soni gave this talk at PyCon Hong Kong 2026. The repository is at github.com/satyamsoni2211/pyconhk-why-fastapi-is-not-fast.
Links
| Resource | Link |
|---|---|
| Source repository | GitHub |
| Slides, PDF | slides.pdf |
| Slides, source (Marp) | talk/slides.md |
| Presenter guide | talk/PRESENTER_GUIDE.md |
| Orders API | orders-api-demo/ |
| Performance checklist | orders-api-demo/CHECKLIST.md |
License
The code is released under the MIT License, copyright 2026 Satyam Soni. The full text is in orders-api-demo/LICENSE.