Boosting Spring Boot + React.js Performance in Production

🚀 How I Solved a Real Spring Boot + React.js Performance Issue This was one of those situations where nothing was technically broken no errors, no outages but users kept saying the same thing: “The application feels slow.” In dev and QA, everything looked fine. The problem only showed up in production, under real traffic and real usage patterns. That’s usually a signal that the issue isn’t obvious and definitely not isolated to one layer. I started by looking at the system as a whole. On the Spring Boot backend, I traced requests during peak usage and noticed thread pools getting saturated and a few APIs doing more work than necessary. Some database queries were returning large datasets when the UI only needed a subset. Tightening queries, adding pagination, and tuning thread and connection pools brought response times back under control. On the React frontend, the slowdown wasn’t React itself. It came from how state was handled. Certain components were re-rendering more often than needed, and large responses were being processed repeatedly. Simplifying state flow and loading heavier parts of the UI only when required made the interface noticeably smoother. The biggest improvement came from treating frontend and backend as one system, not two separate problems. After the changes: Page load times improved API response times stayed consistent during peak hours No additional infrastructure was required The takeaway for me was simple: Performance issues usually come from small, reasonable decisions adding up over time. Solving them means understanding how the application behaves in production and fixing root causes not just reacting to symptoms. #SpringBoot #ReactJS #Java #FullStackDevelopment #ProductionEngineering #SoftwareEngineering

🚀 How I Solved a Real Spring Boot + React.js Performance Issue In one of our production Java full-stack applications, users started reporting slow page loads and a laggy UI especially when the data volume increased. There were no errors. No outages. But the experience clearly wasn’t smooth. The application worked fine in lower environments. The problem only showed up with real users and real data. I looked at the system end to end instead of blaming one side. On the Spring Boot backend, some APIs were returning more data than the UI actually needed. As traffic grew, this extra work caused delays. We optimized queries, added pagination, and tuned thread and connection pool settings to make responses more consistent. On the React frontend, the issue came from state handling. Certain components were re-rendering too often, and large responses were being processed repeatedly. Simplifying state flow and loading heavy UI parts only when required improved responsiveness. Once both sides were fixed together: Page load times improved UI felt smoother even with larger datasets No additional infrastructure was needed Key takeaway: Performance issues usually aren’t caused by one big mistake. They come from small things adding up over time. Solving them means understanding how the application behaves in production and fixing the real causes not just the symptoms. #SpringBoot #ReactJS #Java #FullStackDevelopment #ProductionExperience #SoftwareEngineering

React can feel confusing for Spring Boot developers — and there’s a reason for that. Coming from a structured backend world, React’s flexibility can initially feel chaotic. In this article, I share how I reframed my thinking, mapped familiar Spring concepts to React, and stopped fighting the library. 📘 How React Confuses Spring Boot Developers — and How to Get Past It https://lnkd.in/dEP9vu5b If you’re a backend developer exploring React, this might help make things click.

💭 It started as a “simple Spring Boot project”… I was initially planning to build a basic Spring Boot application just to practice backend concepts. Then I thought: Why not make a URL shortener? After implementing the basics, I felt it was… too simple. So I asked ChatGPT 👀: “How can I enhance my URL shortener?” That’s when things got interesting. I decided to take it a step further and built Linkify — a full-stack URL shortener with a proper dashboard. What I added next: A React-based dashboard to manage shortened links Expiry date support for each short URL Click tracking & analytics Clean UI with real-time data from a Spring Boot backend 🛠 Tech Stack: Frontend: React.js Backend: Spring Boot Architecture: REST APIs This project reminded me that small ideas can evolve into real, production-style applications if you keep asking “what more can I build?” 📌 Note: The project is not on GitHub yet, but I’ll be sharing the repository link shortly after final cleanup and documentation. Would love to hear: 👉 What’s the one feature you would add to a URL shortener? #SpringBoot #ReactJS #FullStackDevelopment #Java #WebDevelopment #SideProjects #LearningByBuilding

🚀 How I Solved a Real Spring Boot + React.js Performance Issue This was a case where nothing was broken, but users kept saying: “The app feels slow.” In dev and QA, everything worked fine. In production, under real usage, screens were slow and APIs took longer during peak hours. I didn’t assume the problem was only backend or frontend. On the Spring Boot side, I found APIs returning more data than needed and threads getting busy under load. Cleaning up queries, adding pagination, and tuning thread and connection pools helped stabilize response times. On the React side, some components were re-rendering too often, and large responses were being processed repeatedly. Simplifying state handling and loading heavier UI parts only when needed made the UI smoother. Once both sides were fixed together: Pages loaded faster API responses stayed consistent No extra infrastructure was added Simple takeaway: Performance issues usually come from small things adding up over time. The fix isn’t a single change it’s understanding how the system behaves in production and addressing the real causes. #SpringBoot #ReactJS #Java #FullStackDevelopment #ProductionExperience

🚀 What is @RestController in Spring Boot? If you're building REST APIs in Spring Boot, this annotation is something you’ll use almost daily. @RestController = @Controller + @ResponseBody That’s it. But what does that actually mean? 💡 Without @RestController If you use only @Controller, Spring expects you to return a view (HTML page). 💡 With @RestController Spring directly returns JSON (or any response body) instead of a view. Now the response is: Hello World Or if returning an object: Spring automatically converts it to JSON using Jackson. ⚙️ What Happens Internally? 1. Spring scans the class 2. Maps HTTP requests via @GetMapping, @PostMapping 3. Converts return object → JSON using HttpMessageConverters 4. Sends response with proper Content-Type: application/json 🧠 When Should You Use It? ✅ REST APIs ✅ Microservices ✅ Backend for React / Angular ✅ Mobile app backend Basically, if you're building an API → use @RestController. 🚨 Common Mistake If you forget @RestController and use only @Controller, you’ll get weird errors like: “Circular view path” or Spring trying to find an HTML template Happens to everyone at least once 😅 👉 If you are preparing for Spring Boot backend interviews, connect & follow - I share short, practical backend concepts regularly. #Java #SpringBoot #Backend #Spring #BackendDevelopment

Alongside my primary frontend work, I’ve been exploring how different backend platforms handle concurrency in real-world systems. One concept that always stood out to me: How Node.js handles thousands of requests with a single thread vs How Spring Boot uses multiple threads for concurrency. Here’s my current understanding: Node.js • Single-threaded event loop for request handling • Async I/O delegated to the system, freeing the main thread • CPU-intensive work offloaded using Worker Threads or child processes → Highly efficient for I/O-heavy, real-time systems Spring Boot (Java) • Multi-threaded request processing using a thread pool • Each request handled by a JVM-managed thread • Parallel execution across CPU cores via context switching → Strong fit for CPU-intensive and enterprise-scale workloads Key takeaway: It’s not about which technology is better. It’s about choosing the right concurrency model for the problem. Expanding my backend exposure alongside ongoing frontend work. For engineers working in production, what factors usually influence the choice between Node.js and Spring Boot? #NodeJS #ExpressJs #Java #SpringBoot #Backend #SystemDesign #Concurrency #FullStack #LearningInPublic

🚀 Day 23/100 - spring-boot-starter-web When you build REST APIs or web applications in Spring Boot, this starter is the best friend 👇 ➡️ What is spring-boot-starter-web? It’s the #foundation starter for building web apps and RESTful services using Spring MVC. ➡️ What does it include? 🔹Spring MVC (controllers, request handling, REST APIs) 🔹Jackson (automatic JSON ↔ Java object conversion) 🔹Embedded Tomcat (run apps instantly with java -jar) No extra setup. No manual wiring. It just works❗ ➡️ Why developers love it ✔ Faster development ✔ Clean REST APIs ✔ Production-ready defaults Add one dependency, and get a full web stack. If you’ve used Spring Boot before, this was probably your first starter :) Next post: https://lnkd.in/dsCTCiNA Previous post: https://lnkd.in/dbNhz8af #100Days #SpringBoot #Java #RESTAPI #SpringBootStarterWeb #BackendDevelopment #WebDevelopment #SoftwareEngineering

🔗 Connecting Spring Boot with React – Simple Flow Explained This diagram explains how a React frontend communicates with a Spring Boot backend using REST APIs. 👉 Spring Boot (Backend) Exposes REST endpoints using @RestController Handles business logic and database operations Sends data in JSON format 👉 API Layer Acts as a bridge between frontend and backend Transfers data securely using HTTP methods (GET, POST, etc.) 👉 React (Frontend) Uses useEffect() and Axios to call backend APIs Receives JSON response from Spring Boot Displays data dynamically in UI components 📌 Flow Summary React ➝ Axios API Call ➝ Spring Boot Controller ➝ JSON Response ➝ React UI 💡 This architecture is commonly used in Java Full Stack applications to build scalable and maintainable systems. #SpringBoot #ReactJS #FullStackDevelopment #RESTAPI #JavaDeveloper #WebDevelopment