This is your reference implementation for system design patterns and distributed systems concepts. It covers the fundamentals you'd expect in a senior engineering interview: CAP theorem, circuit breakers, rate limiting, caching strategies, database sharding, and load balancing algorithms. The code examples are clean and practical, like the circuit breaker with three states and the cache-aside pattern implementation. What I appreciate here is it's not just theory. You get working Python implementations of patterns you can actually adapt, from singleton and factory to write-through caching and weighted round-robin load balancing. It's basically a cheat sheet for building scalable systems, with enough depth to be useful but not so much you're drowning in academic theory.
npx skills add https://github.com/personamanagmentlayer/pcl --skill design-expert