6 Lessons From Code Reviews With a Principal Engineer
After dozens of code reviews with a Principal Engineer, I came away with lessons that changed how I think, code, and collaborate. Here are…
It wasn’t the code I wrote that leveled me up — it was the feedback I got from someone way ahead of me.
6 Lessons From Code Reviews With a Principal Engineer
After dozens of code reviews with a Principal Engineer, I came away with lessons that changed how I think, code, and collaborate. Here are six of the most impactful takeaways.
There’s nothing more humbling than submitting your code for review to a Principal Engineer – and nothing more valuable, either.
I still remember the first time I nervously clicked “Create Pull Request” on a piece of code I was proud of… only to be hit with a tsunami of comments, questions, and gentle (yet brutal) suggestions. But those early reviews shaped me into a better developer, faster than any course or certification ever could.
In this article, I’m sharing six hard-hitting lessons I learned from code reviews with a Principal Engineer – lessons that changed the way I write, think about, and ship code.
1. Clever Is the Enemy of Clear
“If you have to explain it twice, it’s too clever.”
One of my early mistakes was trying to be too smart with my code – compact one-liners, fancy patterns, overly abstract functions. It felt elegant… to me.
My reviewer? Not impressed.
They highlighted that the real test of great code isn’t how clever it looks – it’s how easily the next person can read and maintain it. In production environments, clarity beats cleverness. Every. Single. Time.
What I do now: I write for the reader, not for myself. I optimize for readability, not brilliance.
2. Small Functions, Small Wins
“If your function can’t fit on a screen, it’s doing too much.”
This one hit me hard. I used to write functions that did five things and had four nested if-else blocks.
It worked, but it was hard to reason about.
A Principal Engineer taught me the art of decomposition: break functions into smaller, single-responsibility chunks.
It makes testing easier, reuse possible, and bugs less sneaky.
What I do now: Aim for functions that do one thing well. If I can’t describe what a function does in a sentence, I refactor.
3. Comments Should Explain Why, Not What
“The code shows what it does. Comments should tell me why.”
This was a subtle but powerful mindset shift.
I used to write comments like:
# increment counter by 1
counter += 1Not helpful.
Instead, my mentor encouraged me to use comments to explain intent. Why does this function exist? Why are we skipping validation here? Why is this edge case handled differently?
What I do now: I use comments sparingly, but purposefully — to explain decisions, not describe syntax.
4. Consistency > Personal Preference
“We don’t care how you format code — we care how we do it.”
As someone who liked their tabs a certain way and named variables with a personal flair, I had to learn that in a team environment, consistency wins over creativity.
The Principal Engineer wasn’t dogmatic about their own style — they were dogmatic about the team’s style.
That’s what makes codebases maintainable.
What I do now: I follow the style guide like gospel. Linting, formatting, naming — it’s about harmony, not ego.
5. Your Code Isn’t Your Baby
“Detach emotionally. Your code isn’t you.”
This one was tough.
Early on, every critical comment felt like a personal attack. But it wasn’t.
Good code review culture is about improving the work, not criticizing the person.
Principal Engineers model this well — they’re direct, but kind.
And they expect the same maturity in return.
What I do now: I welcome feedback, defend decisions with data (not emotion), and treat reviews as collaborative conversations, not confrontations.
6. Don’t Just Fix — Learn
“Don’t just apply the change. Understand why it’s better.”
Sometimes I would mindlessly implement suggestions just to get the PR approved faster. But a Principal Engineer once paused my PR and said:
“You didn’t learn anything from this change. Let’s walk through it.”
That moment flipped a switch.
Code reviews aren’t just about approval — they’re about growth.
Every comment is a mini lesson.
What I do now: I read every comment carefully, ask questions, and internalize the reasoning behind suggestions. That’s how you level up.
Final Thoughts: Your Code Is a Reflection of Your Thinking
Code reviews can be uncomfortable, even painful. But that discomfort is a signal of growth.
Working with a Principal Engineer on reviews was like a personal bootcamp in software craftsmanship. It forced me to slow down, think deeper, and build better. If you’re lucky enough to have someone senior reviewing your work — pay attention, ask questions, and treat every comment as gold.
Because at the end of the day, better code isn’t the only outcome. You become a better engineer, too.
Have you learned a powerful lesson from code reviews?
Share it in the comments — I’d love to hear what made you a better developer.
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Let’s grow together — one pull request at a time.
