Exposing JPA Entities in APIs: A Risky Approach

I had an API returning correct data. But response time was too high. Issue turned out to be unnecessary data being fetched from DB. Reduced fields, optimized query. Small change, big impact. #Backend #Java #SpringBoot #Performance

🚨 One mistake that silently kills your backend performance: N+1 queries I hit this in a real project. Scenario: Fetching 100 users → each user loads orders lazily Result? 👉 101 queries instead of 1 💥 Impact: API response time jumped from 120ms → 2.5 seconds Root cause: Hibernate lazy loading without optimization ✅ Fix: - Used JOIN FETCH - Applied DTO projections 💡 Takeaway: If your API is slow and DB looks fine… Check your ORM queries. Hibernate is powerful, but not magical. #Java #SpringBoot #BackendDevelopment #SoftwareEngineering #Microservices #JPA #RESTAPI #DeveloperLife #CareerGrowth

🚀 Day 38/50 – #50DaysOfCode Today, I learned about ArrayList operations — concatenation, slicing, converting between arrays and ArrayLists, and the comparison between Array and ArrayList. Understanding these differences helps in choosing the right data structure effectively. ☕💻 #Day38 #JavaFullStack #Java #CCBP #NxtWave #LearningJourney #Consistency

🚨 Poor logging = nightmare in production I learned this the hard way. 💥 Issue: Bug reported → logs useless Why? - No context - No request IDs - Random print statements ✅ Fix: - Structured logging - Added correlation IDs - Used proper log levels 💡 Takeaway: Logs are your only visibility in production. Write logs like you’ll debug them at 2 AM. #Java #SpringBoot #BackendDevelopment #SoftwareEngineering  #Microservices #JPA #RESTAPI  #DeveloperLife #CareerGrowth

When updating data in a Spring Boot API, standard validation can be too restrictive, often requiring all fields to be sent even for minor changes. A more flexible solution is to use @Validated with validation groups. This approach allows you to define separate sets of rules. For example, you can have a "create" group that requires all fields to be present, and a "default" group that only checks the format of fields that are actually provided in the request. In your controller, you then apply the appropriate rule set: the strict rules for creating new items and the flexible rules for updating them. This allows your API to handle both full and partial updates cleanly while reusing the same data object, resulting in more efficient code. #SpringBoot #Java #API #Validation #SoftwareDevelopment

What actually happens when you hit a REST API? 🤔 Let’s break it down step by step 👇 1️⃣ Client sends HTTP request 2️⃣ Request hits DispatcherServlet 3️⃣ HandlerMapping finds the correct controller 4️⃣ Controller processes request 5️⃣ Service layer applies business logic 6️⃣ Repository interacts with DB 7️⃣ Response is returned as JSON 💡 Behind the scenes: - Jackson converts Java → JSON - Spring handles dependency injection - Exception handling via @ControllerAdvice ⚡ Real benefit: Understanding this flow helps you: ✔ Debug faster ✔ Write better APIs ✔ Optimize performance Next time you call an API, remember — a lot is happening inside 🔥 Follow for more backend deep dives 🚀 #SpringBoot #Java #RestAPI #BackendDeveloper

Doubly Linked List Implementation in Java Today I implemented a Doubly Linked List from scratch to strengthen my understanding of how data structures work internally. What I built: • Converted an array into a Doubly Linked List • Traversed and printed the list • Calculated length of the list • Implemented deletion operations: • Delete head • Delete tail Key Operations Implemented: 1. Convert Array → DLL • Created nodes dynamically • Linked each node using next and back 2. Delete Head • Move head to next node • Remove backward reference 3. Delete Tail • Traverse to last node • Disconnect last node from previous 4. Length Calculation • Traverse the list and count nodes #Java #DataStructures #DSA #BackendJourney #SoftwareDevelopment

How Spring Boot Handles Requests Internally (Deep Dive) Ever wondered what happens when you hit an API in Spring Boot? 🤔 Here’s the real flow 👇 🔹 DispatcherServlet Acts as the front controller receives all incoming requests 🔹 Handler Mapping Maps the request to the correct controller method 🔹 Controller Layer Handles request & sends response 🔹 Service Layer Contains business logic 🔹 Repository Layer Interacts with database using JPA/Hibernate 🔹 Response Handling Spring converts response into JSON using Jackson 🔹 Exception Handling Handled globally using @ControllerAdvice 💡 Understanding this flow helped me debug issues faster and design better APIs. #Java #SpringBoot #BackendDeveloper #Microservices #RESTAPI #FullStackDeveloper #LearningInPublic

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

🚨 Adding indexes blindly can hurt performance Most advice says: “Add index → query becomes fast” Not always true. 💥 Real case: Added index on a frequently updated column Result? 👉 Write performance dropped significantly Why? Indexes slow down INSERT/UPDATE operations ✅ Fix: - Indexed only read-heavy columns - Avoided over-indexing 💡 Takeaway: Indexes are powerful—but expensive. Use them where reads dominate. #Java #SpringBoot #BackendDevelopment #SoftwareEngineering  #Microservices #JPA #RESTAPI  #DeveloperLife #CareerGrowth