Debugging Technique: Restarting Services

Most developers think @Autowired is just dependency injection. It's not ❌ It's Reflection + Proxies + Runtime Wiring. Which means : ⭕ Dependencies are injected at runtime (not compile time) ⭕ You might be calling a proxy, not your actual class ⭕ Field injection hides dependencies and hurts testability ⭕ Startup time increases as your app grows The biggest surprise : 👉 this.method() can bypass Spring logic completely (broken @Transactional) Lesson : "Convenience annotations often hide real complexity." Do you still use Field Injection in production ? #SpringBoot #Java #BackendEngineering #SoftwareArchitecture

A small mistake that cost me hours of debugging  Recently, I faced an issue in backend code that looked simple at first.  But it took hours to fix because I missed one thing:   Understanding the complete flow before debugging  What I learned:   ✔ Trace the full request flow   ✔ Check logs before jumping into code   ✔ Avoid assumptions  Debugging is not about fixing fast, it’s about understanding deeply.  Have you faced similar situations?  #Java #BackendDevelopment #Debugging #SoftwareEngineering

🐛 Debugging is a Superpower Every Developer Needs Real development is not writing code… It’s fixing what breaks. One thing that helped me a lot: 👉 Don’t panic. Read the error carefully. ✔ Check logs ✔ Reproduce issue ✔ Break problem into smaller parts Most bugs are simple — we just overthink them. Great developers = great debuggers. Agree? 👇 #Debugging #Java #Developers #ProblemSolving

Debugging Mindset (From My Experience): It’s important not just to fix the issue but to understand why it happened, or it will come back. My approach includes: - Starting with logs, but not blindly trusting them - Reproducing the issue in a controlled environment - Tracing the full request flow (API → Service → DB) - Identifying the exact breaking point, not just the symptoms - Checking recent changes (deployments, configurations, data) One key learning is that most bugs are not code issues; they are often related to data, configuration, or integration problems. This shift in perspective helps move from simply “fixing bugs” to truly “understanding systems.” #Debugging #SoftwareEngineering #BackendDeveloper #Java

Most backend bugs in production aren't caused by bad code. They arise from assumptions that were never questioned during development. Common assumptions include: - "This API will always return data." - "The network will always be stable." - "No one will hit this endpoint 1000 times a minute." Defensive programming isn't pessimism; it's simply experience wearing a helmet. #BackendDevelopment #SoftwareEngineering #Java #LessonsLearned

I recently encountered an ambiguous mapping error while working on a REST API. The stack trace was overwhelming, but the message was straightforward : I had two different methods competing for the same URL and HTTP verb. The issue happened because I had two methods, createEmployee and createNewEmployee, both annotated with @PostMapping, along with @RequestMapping on the controller class. Spring couldn't determine which method to use to handle the request. To resolve this, it's essential to keep the endpoints unique or utilize different HTTP methods to maintain organization. Happy coding! #Java #SpringBoot #Programming #SoftwareEngineering #Debugging

I once thought writing code was my job. Then I faced my first production issue. The API was working fine locally. But in production, it started failing randomly. - No syntax error. - No obvious bug. - Just failures. That day I learned: Writing code is easy. Understanding failures is engineering. Now I focus more on: - Logs - Monitoring - Edge cases Because real systems don’t fail in IDEs. They fail in production. #Java #BackendDevelopment #SoftwareEngineering #Production #Learning

🐞 Debuggability should be treated as a design requirement. One thing I’ve come to value more over time is this, A system that is hard to debug is hard to own. A lot of teams think about debugging only after something breaks in production. But by then, the real design question has already been answered. If the system does not expose enough context, failure clarity, and traceability, engineers end up doing what they should not have to do during an incident, For me, debuggability is not just about “having logs.” It is about designing systems so that when something goes wrong, we can actually understand • where it failed • why it failed • how far the request got • what state the system is in • what impact it is causing • what can be done next That usually means things like: • Meaningful logs, • Correlation IDs, • Clear status transitions, • Useful error messages, • Visibility across async flows, • Enough context to trace behavior across components. Because in real systems, symptoms and causes are often far apart. The error may appear in one place, while the real issue started much earlier in another service, queue, dependency, or state transition. That is why I think debuggability is a design concern, not just a support concern. A system that works is valuable. A system that can explain itself under pressure is even better. #SoftwareEngineering #SystemDesign #BackendEngineering #ProductionEngineering #Java #SpringBoot

I once saw a piece of code that solved a complex problem in 10 lines. It was clever. Really clever. The kind of code where you read it and think “whoever wrote this really knows what they’re doing.” Then it broke in production. And it took 3 days to figure out why. Not because the logic was wrong. But because nobody - including the person who wrote it - could follow it well enough to debug it fast. That moment stuck with me. Clever code optimises for the moment you write it. Clean code optimises for the moment someone else has to read it at 2am when something is broken. I’ve seen this play out over and over in production systems: The shortcut that made sense at the time. The “it works, ship it” decision. The abstraction that was too smart for its own good. They all feel like wins in the moment. They all become someone else’s problem later. Now when I write code, I ask myself one question: “Will the next person understand this without needing to ask me?” If the answer is no - it’s not done yet. Clever is impressive. Clean is kind. #SoftwareEngineering #BackendEngineering #CleanCode #EngineeringPrinciples #Java

Ever tried to crash a party you weren’t invited to? 🎟️ In the world of Software Architecture, "Sealed Classes" act as the ultimate VIP bouncers for your code. By defining a closed set of permitted subclasses, you gain total control over your hierarchy. The "Triangle" might be a shape, but if it's not on the guest list, it’s not getting in! 🚫🔺 Why developers love this "Club": ✅ Exhaustive Checks: Your compiler knows exactly which types to expect, making your switch or when blocks foolproof. ✅ Domain Integrity: Prevents third-party developers from extending your classes in ways you never intended. ✅ Readability: It makes the relationship between classes clear and predictable at a glance. Coding isn't just about making things work; it's about setting the right boundaries to prevent future bugs. Are you using Sealed Classes to keep your domain models "exclusive," or do you prefer the open-door policy of traditional inheritance? Let’s debate in the comments! 👇 Hashtags: #SoftwareEngineering #CleanCode #ProgrammingTips #Kotlin #JavaDevelopment #Java #Programming #SoftwareEngineering #CleanCode #NullPointerException #CodingHumor #JavaDeveloper #TechTips #BillionDollarMistake #SoftwareDevelopment #BestPractices