Building GraphQL APIs in Java with Quick Start Guide

Is REST really enough for everything… or are we just used to it? I’ve been working with GraphQL lately and spent some time exploring it in detail — and it definitely changed how I think about APIs. So I put together a PDF with what I learned, practical insights, and a few things that made me pause and rethink. Sharing it here — curious to know what you think: Is GraphQL actually better, or just another hype? #GraphQL #APIs #BackendDevelopment #TechDiscussion #Java #RestAPI

🚀 Developed a basic REST API using Spring Boot to handle HTTP requests and responses. 🔹 What I implemented: Created a REST Controller using @RestController Used @RequestMapping to define base URL (/api) Built a GET API using @GetMapping("/student") 🔹 API Endpoint: http://localhost:8080/api/student 🔹 Output: "Student data" 🔹 Key Learnings: How Spring Boot handles HTTP requests Understanding request → controller → response flow Basics of REST API development Excited to move next into POST APIs and sending real data using @RequestBody 🔥 #SpringBoot #Java #BackendDevelopment #LearningJourney #CSE 

🚀 Spring Boot Learning – @RestController vs @RequestMapping While building REST APIs in Spring Boot, I explored how requests are handled behind the scenes. 🔹 @RestController Used to create REST APIs. It combines @Controller + @ResponseBody and returns data directly (JSON/String). 🔹 @RequestMapping Used to map URLs to classes or methods and can handle different HTTP methods. 💡 Modern Approach (Shortcut Annotations) Instead of using @RequestMapping for everything, Spring provides: -> @GetMapping -> @PostMapping -> @PutMapping -> @DeleteMapping These make code cleaner and more readable. 📌 Key Insight: 👉 @RestController creates APIs 👉 Mapping annotations connect URLs to methods Sharing a simple graphical representation to make this concept easier to understand. 📊 #SpringBoot #Java #BackendDevelopment #RESTAPI #DependencyInjection #JavaDeveloper #LearningInPublic

#Post2 In the previous post, we understood what a REST API is. Now the next question is 👇 How do we actually build REST APIs in Spring Boot? That’s where @RestController comes in 🔥 @RestController is a special annotation used to create REST APIs. It combines two things: • @Controller • @ResponseBody 👉 Meaning: Whatever method returns → it is written directly to the HTTP response body (usually JSON for objects) Example: @RestController public class UserController { @GetMapping("/user") public String getUser() { return "Hello User"; } } Output → "Hello User" (sent as response) 💡 Key difference: @Controller → used for returning views (JSP/HTML) @RestController → used for REST APIs (JSON response) Key takeaway: If you are building APIs in Spring Boot → @RestController is your starting point 🚀 In the next post, we will understand how request mapping works using @GetMapping and others 🔥 #Java #SpringBoot #BackendDevelopment #RESTAPI #LearnInPublic

Hot take 🔥 Most developers focus too much on: ❌ Learning new frameworks ❌ Memorizing syntax And too little on: ✅ System design ✅ Debugging skills ✅ Writing clean, maintainable code Frameworks change. Strong fundamentals don’t. Agree or disagree? 👇 #SoftwareEngineering #CleanCode #Java #FullStackDevelopment

🚀 Let’s Talk Real Backend Engineering (Java Edition) One thing I’ve realized while working with Java backend systems — writing code is easy, but writing scalable and maintainable systems is where real engineering begins. Recently, I’ve been diving deeper into how small decisions impact performance at scale 👇 🔍 Some practical learnings from my journey: 👉 1. Why caching matters more than you think Repeated DB calls kill performance. Introducing caching (like Redis) drastically reduces response time and database load. 👉 2. JPA N+1 problem is real ⚠️ Fetching related entities lazily without optimization can lead to multiple unnecessary queries. Using JOIN FETCH or entity graphs can significantly improve performance. 👉 3. API design > just working endpoints Proper status codes, idempotency, pagination, and validation make APIs production-ready — not just functional. 👉 4. Logging & monitoring are underrated Without proper logs, debugging production issues becomes guesswork. Structured logging + monitoring tools = sanity. 💬 Curious to hear from fellow developers: What’s one backend mistake you made that taught you the most? Let’s discuss and grow together 👇 #Java #BackendDevelopment #SpringBoot #Microservices #SystemDesign #JavaDeveloper #TechDiscussion #SoftwareEngineering #CodingLife #Developers #JPA #Hibernate #PerformanceOptimization #Scalability #RESTAPI #TechCommunity #LearnInPublic #BackendEngineer

🚨 Hot take: Most “async” Java code isn’t actually asynchronous — it’s just parallel blocking. I recently reviewed a service using CompletableFuture everywhere… ⚠️ but response time was still bad. ❓ Why? Because .get() was called almost immediately after supplyAsync(). 👉 At that point, the code not doing async — the code just adding complexity. 💡 What actually made a difference: ✅ Letting futures complete without blocking 🔗 Combining results instead of waiting on each call ⚙️ Controlling thread pools instead of relying on defaults 🚫 Async done wrong = harder debugging, unstable latency, pressure on downstream systems 🚀 Async done right = better orchestration, not just faster code 🧠 Most systems don’t have a performance problem — they have a design problem disguised as async. 💬 Curious — how often have you seen “fake async” in real projects? #Java #SystemDesign #Microservices #BackendEngineering #AsyncProgramming #TechLeadership

#SpringUnpackedSeries - 01 Spring Boot is doing a LOT more than you think. You don’t write SQL. You don’t configure much. Yet everything just… works. That’s not magic. That’s layers of abstraction doing the heavy lifting. I’m starting a new series called “Spring Unpacked” where I break down what’s actually happening behind the scenes. First post: 👉 What is Spring Boot + JPA (really)? With a simple mental model you won’t forget. Because once you see it… you can’t unsee it. #SpringUnpacked #SpringBoot #Java #JPA #Backend #BackendDevelopment #Hibernate #SoftwareEngineering

Day 19 of #Leetcode150DaysChallenge Today’s problem: 237. Delete Node in a Linked List Instead of deleting the node directly, we copy the value of the next node into the current node and then skip the next node. This way, the current node effectively becomes the next node, and the original next node gets removed. #LeetCode #DataStructures #Java #ProblemSolving

Backend Development Journey Today I focused on understanding REST APIs and how they work in real-world applications. What I learned: • What REST APIs are and why they are important • How client-server communication works • Basic HTTP methods: GET, POST, PUT, DELETE • How APIs are used in modern applications Key takeaway: REST APIs are the backbone of communication between frontend and backend systems. Learning this is a big step towards building real-world applications. Next step: I’ll start implementing REST APIs using Spring Boot and connect them with a database. #Java #SpringBoot #BackendDevelopment #LearningInPublic