Top 5 Career Mistakes

Hard Lessons Every Developer Must Learn (Before It's Too Late)

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Motivation

Mistakes are the best teachers. There is nothing better than the lessons you gain from failures. Each failure brings disappointment—but it also leads to invaluable growth.

If I could, I wouldn't trade any of my failures—because they've made me a better developer. In this post, I’ll share my five biggest mistakes and how you can avoid them.

Burning Out

I used to work 60-70 hours per week for two years until I burned out. It took me another two years to recover. Never again. When you experience burnout, you lose motivation for work, creativity, and even things you once enjoyed.

Here are 5 things I do to prevent burnout:

• ✅ Ditch alcohol

• ✅ Learn to say No

• ✅ Sport 5 times per week

• ✅ 7-8 hours of sleep at night

• ✅ Mandatory rest day on Sundays

Don't forget that your health is your most important asset. A healthy person wants 1000 things. An unhealthy person wants only one thing: to be healthy.

Ignoring Test-Driven Development

Test-Driven Development (TDD) didn’t click for me from day one. At first, I saw it as a useful but non-essential practice. In retrospect, that was a mistake—I should have adopted it from the very beginning.

Now, I can’t live without TDD. It makes me a better developer in every sense. It’s the gold standard way for writing code, incorporating best practices like clean code, continuous refactoring, and confident shipping.

I don’t always write code. But when I do, I use TDD.

Avoiding Networking

In the digital age, your network is your net worth. Success is not a solo journey—it’s a team effort. Early in my career, I didn’t prioritize networking, and looking back, that was a mistake.

Opportunities don’t just come to you—you create them through networking. Many of my job offers, conference appearances, and friendships are thanks to the network I built.

Don’t forget: A handshake can open more doors than a resume ever will.

Chasing The Latest Tech

Early in my career, I was emotionally attached to my code. But I’ve since realized that code is a liability, not an asset—the only bug-free code is the one that doesn’t exist.

Frameworks and languages are just tools. True expertise comes from timeless, language-agnostic practices like:

• Extreme Programming

• Continuous Delivery

• Test-Driven Development and Test-first mindset

• Pair and Mob programming

• Clean and Pragmatic Architecture

Master these, and you’ll gain far more than by chasing the latest shiny tech.

Over-engineering

Over-engineering kills momentum. Engineers love complex solutions, but complexity isn’t a badge of honor—it’s a liability.

• If a simple function would work, don’t overcomplicate it with a Lambda or Azure Function just because you can

• If WordPress is enough for a simple static site, don’t build it with React or Angular

Future-proofing is valuable, but trying to predict every scaling issue and edge case upfront is a waste of time. Build what’s needed today, iterate when necessary, and keep shipping fast.

Conclusion

Mistakes are inevitable—but they shape us into better developers. You can build a long-lasting engineering career with a healthy lifestyle, language-agnostic skills, and Extreme Programming practices like TDD.

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• The fundamentals of Test-Driven Development

• Three real-world TDD examples in C#, TypeScript and Rust

• The two schools of testing with the five types of mocks

• How to use TDD to design high-quality software

• How to test legacy code

• Refactoring best practices

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