A structured, interview-ready knowledge base for Java backend engineers. Built from first principles — from core Java to cloud-native Spring Boot.
Designed to build deep, durable understanding — not just pass interviews
Every topic starts with why before how. Understand the problem that motivated a solution before learning to use it.
Each note builds from basics to advanced on the same page — no hunting across separate beginner and advanced docs.
Every domain includes Q&A at Beginner → Intermediate → Advanced, calibrated for real backend engineering interviews.
Notes cross-link meaningfully. Follow the thread from Spring beans → IoC → DI → testing without losing context.