2025: In this Code Decode video, we break down the top 3 tricky senior developer interview questions and their answers. Udemy Course Discounted coupon code 💼 What You’ll Learn: ✅ What is a Cold Start in Spring Boot? Understand why your app’s startup time can cause autoscaling failures, serverless timeouts, and production delays — and learn how to fix it. ✅ Real Cold Start Optimization Techniques: Use of /actuator/startup to find bottlenecks Enable lazy initialization Exclude unused auto-configurations Tweak DB and Liquibase setup Use Spring AOT + GraalVM Native Image to reduce startup to lest than 1 second ✅ REST vs gRPC vs Event-Driven: What’s Best in 2025? We explain: When to use REST for simplicity When to choose gRPC for speed Why event-driven architecture is the backbone of scalable, decoupled systems Real-world hybrid strategies that work in production ✅ Handling Breaking API Changes in Microservices Learn how to implement: API versioning Separate DTOs for v1/v2 Feature toggles Contract testing (Spring Cloud Contract) Safe rollout and deprecation strategies ✅ Dealing with Large File Uploads in Spring Boot Avoid memory bloat with streaming Secure your uploads with size limits, antivirus, and safe naming Scale to 100MB+ using pre-signed URLs (e.g., S3) Offload heavy processing to background queues (Kafka, RabbitMQ) 🚨 Plus: We cover the top 10 real production issues in Spring Boot microservices — from memory leaks, thread pool exhaustion, and cascading failures to logging, observability, and retry nightmares — with proactive fixes you can apply today. Mock Interview Playlist: Most Asked Core Java Interview Questions and Answers: Advance Java Interview Questions and Answers: Java 8 Interview Questions and Answers: Hibernate Interview Questions and Answers: Spring Boot Interview Questions and Answers: Angular Playlist: SQL Playlist: GIT: Subscriber and Follow Code Decode Subscriber Code Decode: LinkedIn : Instagram: #seniordev #codedecode #interviewquestions