A series is a set of short posts meant to be read in order. Each one covers a single idea, runs in a plain prompt, and shows real output — every code example here was executed before publishing and checked against what the article claims.
Start at part one, or go straight to the part you need. Every post links to the next.
Python Fundamentals
The Python features you use every day, one at a time. Each part is short, runs in a plain prompt, and shows real output. The order builds: the syntax you write daily, then functions, then how Python actually holds your values, then the tools for structuring code. Every code example here was executed on Python 3.12 and its output checked against what the article claims.
Practical Object-Oriented Python
Classes in Python, and when not to write one. The sequence starts by arguing against reaching for a class, then builds: the object itself, making it readable, controlling access, and choosing between the four things Python gives you for holding data. It ends with the data model, which is the idea the rest of it rests on.
Python Iteration
How Python loops, and how to loop lazily. It starts with the two builtins you reach for every day, opens up what a for statement actually does, turns that into generators, and ends with the standard library that is already written. Every part runs in a plain prompt and shows real output.
C# Algorithm Patterns for Interviews and Contests
Eighty patterns covering what coding interviews and contest problems actually ask for, written in C# 14 on .NET 10. Every pattern gets a worked example traced step by step, a diagram of what moves, runnable code, and the real output from running it. Five patterns per part, sixteen parts.
Go from Basics to REST APIs
Go from the first program to a tested REST API, using only the standard library. Every example runs on Go 1.26 and shows its real output. Hard ideas are explained simply first, then precisely, and the tricky mechanics are animated step by step.
Modern Java: from Basics to Virtual Threads
Java as it is written today: records, sealed types, pattern matching and virtual threads, using only the JDK. Every example runs on Java 25 and shows its real output. Hard ideas are explained simply first, then precisely, and the tricky mechanics are animated step by step.
System Design: from Code Structure to Distributed Systems
System design from the first request to distributed systems: requirements, code structure in C#, Java, Go and Rust, data, consistency, scaling, deployment, security and privacy. Every lesson is interactive, every claim is checked against its source, and every part ends with interview questions.
Qdrant in Practice: Vector Search from First Principles to Production
Vector search with Qdrant, from what an embedding is to a cluster you have deliberately broken and watched recover: HNSW, recall, quantization, filtering, hybrid search, storage, sharding and hardening. Every performance claim is measured against a real Qdrant in Docker, every figure is interactive, and every part ends with interview questions.