I will speed up python code using cython, pyo3 rust, or c extension


About this gig
Slow Python code rarely needs a full rewrite. Usually one loop, one function, one hot path is responsible for most of the runtime and once identified, it can be replaced with a compiled native extension while the rest of your code stays untouched.
If you need to optimize Python code without breaking your architecture, my focus is strictly on measured Python performance optimization: profile first, optimize second. I locate the actual bottleneck using cProfile / py-spy, then rebuild that piece in Cython, PyO3 (Rust), or Pybind11 (C++) with before/after benchmarks so the gain is measured, not assumed.
What's included:
1) Profiling pass to identify the real bottleneck, not a guess
2) Native C/C++ or Rust extension (using Cython, PyO3, or Pybind11), matched to your stack
3) GIL bypass & multithreading for genuine multi-core CPU scaling
4) Before/after benchmarks with measured numbers
5) Clean, documented code - your working logic stays 100% intact
Well suited to: data pipelines, NumPy/Pandas processing, backend APIs under load, and any CPU-bound script where adding more servers isn't a real fix.
Not sure if your code can be optimized? Message me for a quick assessment
Get to know Syed Rehan
Low Level Systems and Performance Engineer
- FromPakistan
- Member sinceJun 2023
- Avg. response time4 hours
Languages
Urdu, English
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FAQ
Will my production server need C++ or Rust compilers installed to run this?
Not necessarily. Depending on your deployment setup, I can compile the native extension into standard Python wheel files (.whl) or compiled binaries (.so / .pyd) targeted for your exact OS and Python version. This allows you to install it via standard pip install without needing compiler.
How do you verify the actual speedup?
I profile your code baseline using cProfile or py-spy before making any changes. After optimizing, I deliver a detailed benchmark report with exact before-and-after execution times.
Which tool will you use: Cython, C++, or Rust?
I match the tool to your stack: PyO3 (Rust) for modern memory safety, Pybind11 (C++) for heavy math or existing C++ codebases, or Cython for fast, lightweight native integrations.
What if my code is delayed by database or network latency instead of CPU usage?
Native compiled extensions accelerate CPU execution. If initial profiling shows your bottleneck is I/O latency rather than CPU cycles, I'll give you an honest assessment upfront before you spend your budget.
Will I need to rewrite my entire Python codebase?
No. I only rewrite the specific bottleneck function or loop into a compiled binary extension (.so/.pyd). Your overall project architecture and remaining Python logic stay completely untouched.

