10 lessons I learned the hard way as a software engineer

Imagine stepping into a time machine. What advice do you bring back?

Jan 25, 2025

Looking back, there’s so much I wish I’d told my younger self in tech. Not only about writing code, but about the mindset, the career, and the real life behind it. If you're starting out or stuck midway, these 10 lessons are for you. Each comes with a story, a tip, and a push you’ll actually remember.

1. Coding is important, but communication is everything.

You can write great code, but if you can't communicate, it won’t matter. Clear writing, clear thinking. This is how ideas spread and projects ship. Explain your work simply, document it well, and keep your team in sync.

Example:

Imagine you built an algorithm that’s 40% faster. Great. But if you can’t explain it clearly, no one will care. Impact only matters if others understand it.

Action Item:

Practice explaining your work in a simple way. Try writing one short paragraph like you're talking to a 5th-grade friend. By the way, this will help you in job interviews as well. Clear answers matter more than fancy words. A friend once failed the LeetCode problem but got the job by explaining their project well.
Be active in team discussions and retrospectives. Focus on being clear and concise.

2. Code reviews aren’t critiques. They’re conversations.

When I started, code reviews felt scary like people were only looking for mistakes. Now I see them as chances to learn and grow. Each comment helps me write better code.

Action Item:

Ask for specific feedback when submitting your code. For example, “I’m unsure about my error handling here. Thoughts?”

3. The best debugging tool is a break.

You know that feeling when you’ve been staring at a bug for hours, only to solve it in 10 seconds after stepping away? Yeah, that’s not a coincidence.

Example:

I spent entire afternoon on a bug which was a small mistake with a variable. A short coffee break helped me spot it fast. Sometimes stepping away solves more than staring at the screen.

Action Item:

When stuck on a bug, set a timer for 30 minutes. If you’re still stuck when it rings, take a walk, grab a coffee, or do something non-technical before coming back.

4. One bug, one fix, one lesson.

Every bug is a learning opportunity whether in code or in life. When you encounter one, don’t just patch it. Ask yourself: How did this happen? What can I do to prevent it next time?

Example:

After fixing a production issue, I also improved logging, monitoring, and tests.
That way, we can catch problems earlier next time.

Action Item:

After big bugs, review what went wrong. Use techniques like the Five Whys to find out why it happened. Write down the cause, the fix, and how to prevent it.
Add a new test for each bug to stop it from happening again. One bug, one fix, one unit test.

5. Mistakes are part of the process.

No matter how experienced you become, bugs will still find their way into your code. That’s okay. Mistakes aren’t failures; they’re feedback.

Example:

A junior engineer deleted a column from the live database by mistake. We didn’t blame them but used this incident to add better safety checks.

Action Item:

When you make a mistake, write down what happened, what you learned, and how you’ll do better next time.
Encourage a blame-free culture on your team. Focus on solutions, not blame.

6. Don’t over-engineer.

Early on, I thought great code meant handling every edge case and future feature. Now I know: simple code always wins.

Example:

I once built a complex config system for a feature that only needed two settings. Looking back, a simple approach would've been easier to build and maintain.

Action Item:

Before you start, ask: “What’s the simplest way to solve this?”
Follow YAGNI (You Aren’t Gonna Need It): don’t build features until you need them.

7. Test your code. Future you will thank you.

Writing tests can feel tedious, but they save time and catch bugs when it matters most. They give you confidence to ship and refactor. Seriously. Never refactor without them.

Example:

I built a key feature which broke in production due to missing input checks. One simple test would've caught it.

Action Item:

Set a goal to write at least one unit test for every new function, feature, bug you create.
Use code coverage tools to spot missing tests.

8. Learn the business side.

Knowing why a decision is made matters as much as knowing how to build it. Software solves real problems. It is not code for code’s sake.

Example:

I worked on a notification feature that felt useless. After release, users left so many comments that it helped them catch key updates. That changed my view of the problem.

Action Item:

Talk to product managers or join customer feedback sessions to learn user needs.
Learn basics like ROI, KPIs, and customer personas to understand your work better.

9. Efficiency is your superpower.

Small improvements grow over time. Faster typing, better tools, ChatGPT make a big difference.

Example:

By automating a weekly data-cleaning task that used to take an hour, I saved my team 50 hours per year.

Action Item:

Invest time in learning keyboard shortcuts, IDE features, and productivity tools.
Look for repetitive tasks in your workflow and script or automate them.

10. The “perfect” job doesn’t exist.

There’s no single role or company that will check every box. Focus on growth, impact, and culture over perfection.

Example:

A friend of mine switched teams or Big Tech jobs over small disagreements. But different opinions are normal and part of the process.

Action Item:

Make own list of must-haves like learning, work-life balance or big salary. Then choose roles that fit.
Think about your long-term career goals and pick roles that match them.