Spring Boot Interview QnA (2026) Spring Boot is now the default choice for building Java backend and microservices applications, so it appears in almost every Java interview. This article collects the most important Spring Boot interview questions with simple explanations, diagrams, and code examples so even beginners can follow along. Basics of Spring Boot: Spring Boot Interview QnA 1. What is Spring Boot? Short answer: Spring Boot is a framework built on top of the Spring Framework that makes it easy to create production‑ready, stand‑alone applications with minimal configuration. Simple explanation: Traditional Spring needs a lot of XML/Java configuration, manual server setup, and dependency management. Spring Boot gives you sensible defaults, auto‑configuration, and embedded servers (like Tomcat), so you can focus on writing business logic instead of infrastructure