Improving API Response Time with Async Processing

🌐 REST APIs: Simple in Theory, Tricky in Reality Creating APIs is easy. Designing GOOD APIs is hard. Here’s what I learned: ❌ Bad: /getUserData ✅ Good: /users/{id} ❌ Returning everything ✅ Returning only required data (DTO) ❌ Ignoring status codes ✅ Using proper HTTP responses (200, 404, 500) Small improvements = Professional APIs 🚀 What’s one API mistake you’ve seen often? #RESTAPI #Java #SpringBoot #Backend

Most developers call APIs every day but very few understand what actually happens behind the scenes Swipe through this This is how I started looking at backend systems more clearly In the beginning it felt simple request goes in response comes out but there is a lot happening in between how requests are routed how controllers handle them how services process logic how databases are queried and how responses are built and sent back Once I understood this flow debugging became easier design decisions started making more sense The more I learn the more I realise backend is not just endpoints it is a complete flow Still learning and improving What part of request flow feels confusing to you #Java #SpringBoot #BackendDevelopment #SystemDesign #SoftwareEngineering

Recently, I shared how reducing multiple API calls improved performance. This time, I ran into a different issue. My API response looked fine… until I saw the payload size. While working on a feature, everything was working as expected. But the response felt heavier than it should be. After checking, I realized I was returning full objects, even when only a few fields were actually needed. So for a single request, I was sending a large JSON response unnecessarily. I made a small change: Instead of returning everything, I started sending only what the client actually needs. Used DTOs to control the response and removed unused fields. That made a clear difference: - Smaller payload - Faster response - Cleaner API Last time, the issue was too many API calls. This time, it was too much data in one call. (Check the previous post: https://lnkd.in/gxSKFVbk) Sometimes performance issues are not about complex fixes… they’re about reducing unnecessary work. #Java #BackendDevelopment #SpringBoot #API #Performance #LearningInPublic

🚀 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 

🚨 @Transactional doesn’t always work the way you think I assumed it works everywhere. I was wrong. 💥 Issue I faced: Transaction was NOT rolling back on failure. Root cause? Method was called internally within the same class. Spring uses proxies → internal calls bypass them. ✅ Fix: * Moved logic to separate service class 💡 Takeaway: @Transactional works only when called via Spring proxy. This is one of those bugs that wastes hours. #Java #SpringBoot #BackendDevelopment #SoftwareEngineering  #Microservices #JPA #RESTAPI  #DeveloperLife #CareerGrowth

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

Recently worked on improving API performance in a backend system ⚡ 📉 Problem: High response time under load 🔧 What I did: Optimized DB queries Introduced caching Refactored inefficient logic 📈 Result: ~40% performance improvement 🚀 💡 Lesson: Performance issues are rarely about one thing — it’s always a combination. Small improvements → Big impact. #BackendDevelopment #PerformanceOptimization #Java #Engineering

#Post7 In the previous post, we saw how to handle exceptions globally using @ControllerAdvice. Now let’s take it one step further 👇 How do we handle specific errors properly? That’s where Custom Exceptions come in 🔥 Instead of using generic exceptions, we can create our own exception based on the use case. Example: public class UserNotFoundException extends RuntimeException { public UserNotFoundException(String message) { super(message); } } 👉 Now we can throw this exception when user is not found Example usage: if(user == null){ throw new UserNotFoundException("User not found"); } 💡 Why use Custom Exceptions? • Better error clarity • Easy debugging • More control over API responses Key takeaway: Use custom exceptions to make your API errors more meaningful and structured 👍 In the next post, we will understand validation using @Valid 🔥 #Java #SpringBoot #BackendDevelopment #RESTAPI #LearnInPublic

Define once in OpenAPI. Generate DTOs, interfaces, and docs automatically. Less boilerplate. Fewer inconsistencies. Cleaner API development. #OpenAPI #Java #SpringBoot #RESTAPI #APIDesign #BackendDevelopment #SoftwareEngineering #CodeGeneration

I didn’t realise the problem at first… everything was working. But something felt slow. While working on a feature, I noticed that for a single action, the system was making multiple API calls in the background. Each call was fast on its own. But together, they were adding up. That’s when it clicked, the issue wasn’t the API speed, it was the number of calls. So instead of calling the API again and again, I combined the data and handled it in a single request. That small change made a clear difference. The response felt quicker, and the flow became much cleaner. It was a simple fix, but a useful reminder: Sometimes performance issues are not about optimization… they’re about reducing unnecessary work. #Java #BackendDevelopment #APIDesign #Performance #FullStackDeveloper #LearningInPublic