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10 Most Common Junior Developer Mistakes

26. 09. 2025 1 min read intermediate

We’ve all made these mistakes. Here’s how to skip them.

1. Copying from StackOverflow Without Understanding

The code works, but you don’t know why. When it breaks, you don’t know how to fix it. Always understand what you copy.

2. Over-engineering

“We need microservices, event sourcing and Kubernetes” for a TODO app. KISS — Keep It Simple.

3. Not Writing Tests

“I don’t have time for tests.” Do you have time for debugging? Tests save time, they don’t cost it.

4. Fear of Asking Questions

You spend 2 hours googling something a colleague can explain in 5 minutes. Ask questions.

5. Ignoring Error Handling

// ❌  
try { doSomething() } catch(e) {}  
// ✅  
try { doSomething() } catch(e) { logger.error(e); throw e; }

6. No Version Control Workflow

Commit often, use branches, write meaningful commit messages.

7. Tutorial Hell

Watching tutorials isn’t programming. Build your own projects. It hurts, but you learn 10× faster.

8. Premature Optimization

“I need Redis cache” for an app with 10 users. First working code, then optimization.

9. Not Learning Your Tools

Git, IDE, terminal, debugger — time invested in tools pays back multiple times.

10. Comparing Yourself to Seniors

A senior has 10 years of experience. You have 6 months. That’s OK. Focus on your own growth.

Tip

All seniors were juniors once. Mistakes are normal — what matters is learning from them.

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