Mastering Performant Code in Python is a hands-on blueprint for seasoned Python developers who want to go beyond theory and actually build the data-structure and optimisation skills the job market rewards. If you can read a Big-O graph, write a class, and run a unit test, this book picks up from there and takes you all the way to production-ready, profiled, and benchmarked code. Why this book? Implementation-first : every concept is introduced by writing it, testing it, timing it. You don’t just read about AVL trees or Bloom filters—you ship them, with type hints and 100 % test coverage . - Performance obsession : each chapter ends with side-by-side speed and memory tables so you can see exactly when a hand-rolled structure outpaces a Python built-in . - Real-world focus : text-editor buffers, in-memory DBs and caching layers show up as worked examples, proving the techniques survive outside the REPL . - What you’ll master CPython internals—how lists resize, how dict hashing really works, and the memory layout that makes some operations O(1)O(1) and others O(n)O(n) . - Fifteen+ data structures built from scratch, from dynamic arrays through balanced trees to probabilistic filters, each wrapped in modern Python idioms (dataclasses, context managers, mypy-friendly types) . - A profiler’s toolbox: timeit, cProfile, tracemalloc, plus statistical benchmarking harnesses you can drop into any codebase . - Production optimisation moves—__slots__, object pools, Cython fall-backs, and a full deployment pipeline that bakes in performance tests and CI/CD hooks . - How you’ll learn A repeatable seven-step chapter pattern (Motivation → Theory → Implementation → Tests → Benchmarks → Applications → Exercises) keeps the pace brisk yet structured . - Over fifty graded exercises—many open-ended—push you to tweak growth factors, hunt memory leaks, and make thread-safe variants until the knowledge sticks . - Zero external dependencies: the entire journey runs on the standard library so you spend time learning fundamentals, not wrangling installs . By the final page you’ll have a personal toolbox of battle-tested data structures, the instinct to profile before you guess, and the confidence that comes from watching your code outrun the stock implementations. If your next milestone is a system that has to stay fast at scale—or an interview where “implement an LRU cache” is just the warm-up— Mastering Performant Code in Python will get you there.