Part 9 of 10 of Building Instagram's Authentication Backend . If you're just joining, the repo is here and you can catch the earlier parts on the YouTube playlist . Eight parts of code, zero runs By the end of part 8, every layer of this backend existed: DTOs, exceptions, entities, repositories, five services, a security filter chain and a controller. And I had never started the application. Not once. Everything so far was code I'd reasoned through and believed would work. This part is where that belief gets tested. We containerize the app, put Postgres, Redis and a fake mail server next to it, and bring all four up with one command. It did not work the first time, so this post is the real debugging session, with each bug, its symptom and its fix. If you're containerizing your own Spring Boot app, there's a good chance you'll hit at least one of these. In this post: A multi-stage Dockerfile for Spring Boot, line by line A docker-compose.yml ...
Python Developer Roadmap (2026): From Beginner to Job-Ready Python has evolved from a simple scripting language into one of the most versatile and in-demand programming languages in the world. In 2026, Python is widely used for backend development, automation, data-driven applications, and interviews across startups and large companies . If you are confused about where to start , what to learn next , and how to prepare for jobs , this Python developer roadmap will give you a clear, structured path from beginner to job-ready Python developer. This roadmap is intentionally balanced: Beginner-friendly Backend-oriented Interview-focused Who Should Follow This Python Developer Roadmap? This roadmap is ideal for: Complete beginners starting their programming journey Java or other language developers switching to Python Backend developers expanding their skill set Professionals preparing for Python interviews Students aiming for software developm...