José Peixoto’s Post

One of the biggest mistakes I made early in my backend career? I underestimated logging and observability. When I started building APIs with Java and Spring Boot, my focus was mostly on: • Writing business logic • Making the API work • Connecting to the database Everything seemed fine… until something broke in production. And then the real problem started. No useful logs. No clear error messages. No way to trace what actually happened. Debugging production issues felt like trying to solve a puzzle with missing pieces. That experience taught me something important: If you can’t observe your system, you can’t reliably run it. Today when building backend services, I always think about observability from the beginning: ✔ Structured logging ✔ Meaningful error messages ✔ Correlation IDs for tracing requests ✔ Monitoring metrics (latency, error rates) ✔ Alerts for critical failures These things might not feel important when you're writing the first version of an API. But they make a huge difference when your system is running in production. Clean code is important. But observable systems are maintainable systems. Curious to hear from other developers 👇 What’s one backend mistake that taught you an important lesson? #BackendDevelopment #Java #SoftwareEngineering #SpringBoot #DevLessons

📂 Understanding #Spring_Boot_ProjectStructure Today I explored the basic project structure of a Spring Boot application, and it made backend development feel much more organized 🚀 Here’s the simple breakdown 👇 📁 src/main/java This is where we write the main Java code: ✔ Controllers ✔ Services ✔ Models ✔ Repositories 📁 src/main/resources This folder contains important resources like: ✔ application.properties → configuration settings ✔ static → HTML, CSS, JS files ✔ templates → Thymeleaf templates 📄 pom.xml This file contains all the project dependencies and Maven build configuration. 💡 What I learned: A clean project structure makes development easier, scalable, and beginner-friendly. Understanding folders is the first step to building real Spring Boot applications 💻✨ Excited to dive deeper into controllers and REST APIs next 🚀 #SpringBoot #Java #BackendDevelopment #LearningJourney #ProjectStructure #DeveloperLife 10000 Coders

SOLID Principles in Java – Explained Simply When building scalable and maintainable software, following good design principles is essential. One of the most important concepts in Object-Oriented Programming is SOLID Principles. SOLID is a set of five design principles that help developers write clean, flexible, and maintainable code. Let’s understand them in a simple way. 1️⃣ Single Responsibility Principle (SRP) A class should have only one responsibility or one reason to change. Bad example: A class that handles database operations + business logic + logging. Good approach: Split them into separate classes. Example: OrderService → Business logic OrderRepository → Database operations LoggerService → Logging This makes the code easier to maintain and test. 2️⃣ Open/Closed Principle (OCP) Software entities should be open for extension but closed for modification. Instead of modifying existing code, we should extend it using new classes. Example: Add a new payment method by creating a new class rather than modifying existing logic. 3️⃣ Liskov Substitution Principle (LSP) Objects of a superclass should be replaceable with objects of its subclass without breaking the application. Example: If Bird is a parent class, any subclass like Sparrow should work correctly wherever Bird is used. 4️⃣ Interface Segregation Principle (ISP) Clients should not be forced to depend on interfaces they do not use. Instead of creating large interfaces, split them into smaller, specific ones. Example: Vehicle Driveable Flyable This keeps interfaces clean and focused. 5️⃣ Dependency Inversion Principle (DIP) High-level modules should not depend on low-level modules. Both should depend on abstractions (interfaces). In Spring Boot, this is achieved using Dependency Injection. Example: @Autowired private PaymentService paymentService; This makes the system loosely coupled and easier to maintain. Why SOLID Principles Matter Following SOLID principles helps to: ✔ Improve code readability ✔ Reduce tight coupling ✔ Make applications easier to scale ✔ Improve maintainability These principles are widely used in Java, Spring Boot, and enterprise applications. Tech Stack I work with: Java | Spring Boot | REST APIs | PostgreSQL | React #Java #SpringBoot #SOLIDPrinciples #CleanCode #SoftwareEngineering #BackendDevelopment

💡 The Magic Behind Spring: Annotations!!!!! When I first started learning Spring Framework, everything felt… complicated. XML configurations, long setups, and too much wiring. It felt like building a house by manually connecting every wire. Then I discovered Annotations and everything changed. 1. Suddenly, my code became smarter. 2. My configurations became cleaner. 3. And development became faster. Instead of writing pages of configuration, I could simply say: 👉 @Component – “Hey Spring, manage this class.” 👉 @Autowired – “Please inject the dependency for me.” 👉 @RestController – “This class handles web requests.” It felt like having a conversation with the framework instead of commanding it. Why are annotations so important? Because they: Reduce boilerplate code Improve readability Enable dependency injection effortlessly Make applications more scalable and maintainable 📌 In simple words: Annotations are the language through which developers communicate with Spring. And once you understand them, Spring doesn’t feel complex anymore it feels powerful. 🚀 Still learning, still exploring… but every small concept like this makes the journey exciting. #SpringBoot #Java #LearningJourney #BackendDevelopment #WomenInTech #knowledgeshare

Architecture vs. Speed: When is 8 classes for one task actually worth it? 🚀 As a Senior Developer, I often see a common struggle: when to keep it simple and when to build a robust architecture. In my latest video for Let’s Code Java, I took a simple console app and transformed it into a professional, service-oriented system. The result? I added 8 new classes (builders, services, exception hierarchy), but technically... I didn’t add a single new feature. Was it worth it? It depends. If you're building a prototype, this level of engineering will only slow you down. But if you’re working on a long-term enterprise project, skipping this foundation will cost you twice as much time later when you have to refactor "dirty" code. In this episode, I dive deep into: ✅ Building a Custom Exception Hierarchy that doesn't mess up your logic. ✅ Implementing a Service Layer to isolate business rules from I/O. ✅ Using the Builder Pattern to ensure object validity from the start. ✅ Preparing the ground for Spring Boot & REST API. If you want to see how to design Java applications that are ready for the real world (and why "perfect" code isn't always the goal), check out the video in the first comment. Question for my fellow devs: Where do you draw the line between "clean architecture" and "over-engineering"? Let’s discuss in the comments! 👇 #Java #SoftwareArchitecture #CleanCode #BackendDevelopment #JavaDeveloper #ProgrammingTips #SpringBoot #LetsCodeJava

Learning Backend Development the Right Way (Spring Boot + System Thinking) Today, I didn’t just write code — I focused on understanding the why behind the code. * What I built: 1. Started designing a “Create Super Admin” feature using Spring Boot 2. Structured backend using a feature-based approach (users, auth) 3. Created User Entity step-by-step * What I learned (Concepts > Code): 🔹 OOP (Object-Oriented Programming) → Class as a blueprint (User) 🔹 JPA & ORM → Mapping Java class to database using @Entity 🔹 Database Design → Primary Key using @Id 🔹 System Design Thinking → Designing structure before connecting database (Code-first approach) 🔹 Spring Boot Internals → Component Scanning, IoC Container, Auto Configuration 🔹 Clean Architecture → Feature-based folder structure instead of layer-based * Key Insight: “First design the system, then connect the database — not the other way around.” This approach is helping me think like a backend engineer, not just a coder. #SpringBoot #BackendDevelopment #Java #SystemDesign #LearningInPublic #100DaysOfCode

🚀 Entity Management Best Practices in Spring Boot When building applications, managing entities in a single module can quickly become messy and difficult to maintain. As projects grow, this approach leads to tight coupling and poor scalability. 💡 A better approach is using a Multi-Module Architecture in Spring Boot. Instead of placing everything together, we can separate responsibilities into different modules: 🔹 User Module – Handles user-related logic 🔹 Auth Module – Manages authentication and authorization 🔹 Profile Module – Handles user profile data ✅ Benefits of Multi-Module Architecture: - Better code organization - Easier maintenance and scalability - Improved separation of concerns - Cleaner and more modular project structure Adopting these best practices makes your backend architecture more robust, scalable, and developer-friendly. If you're learning Java, Spring Boot, and backend development, understanding modular architecture is a valuable skill for building real-world applications. #Java #SpringBoot #BackendDevelopment #SoftwareArchitecture #Microservices #JavaDeveloper #Coding #Programming

Here’s another trending-style LinkedIn post, this time focused on a hot topic in the Java world right now — Virtual Threads & Project Loom: Java is quietly solving one of the biggest problems in backend development: scalability without complexity. With Virtual Threads (Project Loom) now part of modern Java, building highly concurrent applications is becoming much simpler. For years, developers had to choose between: • Thread-per-request (simple but not scalable) • Reactive programming (scalable but complex) Now, Java offers a third option: 👉 Write simple, blocking-style code that still scales efficiently. In real-world microservices, this changes a lot: • Handling thousands of concurrent requests becomes more manageable • Cleaner, more readable code compared to reactive pipelines • Reduced need for complex async frameworks • Easier debugging and maintenance But it’s not just about using Virtual Threads — it’s about using them wisely. Understanding when to use them (I/O-bound workloads) vs when not to (CPU-heavy tasks) is what makes the difference. Java isn’t chasing trends — it’s solving real engineering problems in a practical way. And that’s exactly why it continues to stay relevant in modern backend systems. #Java #ProjectLoom #VirtualThreads #BackendDevelopment #Microservices #SoftwareEngineering #TechTrends

💡 One thing I’ve learned as a Backend Developer… Writing code is easy. Writing scalable and maintainable systems is where the real challenge begins. While working with Java & Spring Boot, I’ve realized: 🔹 Clean architecture matters more than quick fixes 🔹 Performance optimization is not optional at scale 🔹 Handling edge cases is what separates good code from production-ready code 🔹 Debugging teaches more than development Improving API performance and reducing response time has consistently shown me how even small backend optimizations can significantly enhance user experience 🚀 Always learning. Always improving. Curious to know — what’s one backend lesson that changed the way you write code? #BackendDevelopment #Java #SpringBoot #SoftwareEngineering #TechLearning #Developers #CodingJourney