Real-world insights from the trenches of senior engineering no fluff, no gatekeeping, just hard-earned truths
Introduction
Let’s be honest: the internet is overflowing with feel-good developer advice. “Write clean code.” “Use version control.” Cool story, bro. But what happens when you’re neck-deep in a spaghetti codebase with legacy bugs older than your GitHub account? That’s where real lessons begin.
I was lucky and unlucky enough to work under a principal engineer who didn’t sugarcoat anything. Think senior dev meets Jedi master, minus the lightsaber and plus a ton of passive-aggressive code reviews. He didn’t just teach me how to write better code he rewired how I think as a developer.
This isn’t another list of beginner tips. These are 15 survival rules forged in production fires, architecture wars, and “why the hell is this breaking at midnight” moments. Some are about mindset, others about code, but all of them stuck with me long after I stopped reporting to that engineer.
Let’s dive in. Your future self will thank you.
Or at least not curse your commit messages.
1. Respect the blueprint even if you think it’s trash
Early in my dev journey, I looked at old system designs the same way a gamer looks at lag: rage first, understand later. I’d open a codebase, spot an “obviously wrong” pattern, and immediately start planning how to “fix” it. Rookie move.
Then the principal engineer told me this:
“If the system is still running and making money, maybe the code isn’t dumb. Maybe you just don’t get it yet.”
Oof.
Here’s the thing: most systems weren’t designed for you. They evolved. Someone patched things under pressure, someone else rewrote half of it during a migration, and another dev duct-taped a feature at 3 A.M. because a VP wanted it live yesterday. That mess? It’s still production gold. Learn to read it before trying to rewrite it.
It’s easy to disrespect legacy code. It’s harder and far more valuable to understand why it’s built the way it is.
Lesson: Before refactoring, study the architecture. Talk to the person who wrote it. Check the commit history. Try to understand the business logic behind it.
Your job isn’t just to write code. It’s to not break what’s already working.
3. Don’t chase ‘clever’ chase clarity
Let’s talk about that time I wrote a piece of code so “elegant” it looked like it belonged in an academic journal. It was recursive, map-reduced, one-liner magic.
It also broke on every third edge case, no one understood it (including me a week later), and my principal engineer left a one-line review:
“This is clever. That’s not a compliment.”
Ouch. But also… fair.
See, junior devs often think being clever means being senior. But in reality, clarity is king. You want code that your future self or teammate can glance at and grok without an espresso IV drip.
Think about the dev who will come after you. They won’t remember your genius only your variable names. They’ll curse your ternary chains, not praise your “elegant lambda wizardry.”
Clean, boring, readable code wins. Every. Time.
Lesson:
If you need a comment to explain what a line does, the code probably sucks. Make it obvious. Self-documenting logic is the goal.
Real quote from my mentor:
“Write code like the person maintaining it next is a sleep-deprived intern with a deadline.”
4. Always leave the codebase better than you found it
Here’s a rule that sounds small but scales like crazy:
“If you touch the code, clean it up.”
No, I’m not saying rewrite the whole module because your linter flinched. I’m saying fix the formatting, rename that cursed variable (tempData123), delete the unused import, or extract that repeated logic into a function. Small wins, big impact.
Think of it like the Boy Scout Rule for devs: leave the campsite cleaner than you found it. Because if every engineer does that even once a day the whole codebase starts to feel breathable again. Less “haunted house,” more “tidy cottage.”
One of my first real PRs was a bug fix. But before merging, the principal engineer added a comment:
“Good fix. Now rename that variable that made you cry earlier.”
He was right. If you hate something in the code, fix it. Future-you (and your teammates) will silently thank you during the next refactor sprint.
Lesson:
Refactoring isn’t just a feature of sprints it’s a part of your daily hygiene. Leave the code a little less chaotic than you found it.
5. Ask better questions, get better answers
Ever walk up to a senior dev and blurt out:
“It’s not working. Can you help?”
And they just blink at you like you forgot how speech works?
Yeah. Same.
One of the most underrated dev skills is asking good questions. I’m talking about the kind that shows you’ve thought, debugged, poked, logged, and cried before asking for help.
My principal engineer gave me a checklist that changed my life:
- What were you expecting to happen?
- What actually happened?
- What did the logs say?
- What did you try already?
The moment I started asking “What changed since the last successful run?” instead of “Why is this broken?” I started getting better answers. More importantly, I started solving more things myself.
Also: don’t underestimate the power of explaining your problem out loud. Rubber duck debugging isn’t a meme it’s a weapon.
Lesson:
Debugging is part communication, part investigation. Be specific. Be detailed. And yes, talk to your rubber duck (or your coffee mug, no judgment).
Bonus Tip: Name your rubber duck something dramatic like “Debugger Prime.” Makes the process feel cooler.
6. Log like the next person is blind
Imagine you’re on-call at 2 a.m. Production is on fire. And the logs just say:
“Error: Something went wrong.”
Thanks, Sherlock. Super helpful.
Logging isn’t about you it’s about the poor soul (probably future-you) who will be digging through the chaos trying to figure out why the system is coughing up blood.
My principal engineer’s golden rule?
“Write logs like the next person debugging this has no context and zero patience.”
A good log message is clear, specific, and ideally answers the question: what, where, and why something happened. Use structured logging. Include IDs. Timestamps. Don’t log sensitive data (unless you like emails from Legal).
Bad log:
[WARN] Unexpected result.
Good log:
[WARN] Order service returned null for orderId=89423 during status update
See the difference?
And please, don’t log just because you can. Noise is as bad as silence. Think signal-to-noise ratio.
Lesson:
Logs are your lifeline in production. Make them useful, or don’t bother writing them.
Bonus Tip: If your log messages read like a bad fortune cookie, rewrite them.
7. Learn your tools like they’re your weapons
Every dev has a toolkit IDE, terminal, Git, debugger, browser dev tools, maybe some Vim sorcery or Emmet shortcuts. But not every dev masters their tools.
There’s a difference between using VS Code and making it your sidekick in battle.
My principal engineer used shortcuts like a concert pianist. Watching him navigate files, jump to definitions, batch rename variables, or stage chunks in Git was… beautiful. Like watching a hacker in a heist movie. Meanwhile, I was still copy-pasting file paths like a medieval scribe.
He told me this:
“A carpenter doesn’t blame the hammer. They sharpen it.”
Boom.
Learn the shortcuts. Customize your terminal. Install useful extensions. Understand how your linter works. Read the damn Git docs (no, really). These things save time, reduce errors, and make you look like you actually know what you’re doing.
Here are a few examples:
-
VS Code:
Ctrl+Pto jump to files,Ctrl+Shift+Lfor multi-cursor editing -
Git:
git add -p,git log --graph --oneline --all -
Terminal: Learn
grep,awk,jqyou’ll feel like Neo
Lesson:
Treat your tools like weapons. The sharper they are, the faster you move. Don’t just “kind of know them” master them.
8. Own your failures and your merges
There’s a moment in every dev’s life when you push a change… and suddenly the app explodes in staging. Or worse production.
Maybe it was a missing await.
Maybe it was a console.log left in a loop.
Maybe it was you thought rebasing was safe.
Whatever it was, it’s now a team problem. And you have two choices:
- Try to quietly fix it and hope no one notices
- Or say, “Yep, that one’s on me here’s how I’m fixing it”
Guess which one earns you long-term respect?
My principal engineer caught one of my borked merges during a release freeze. Instead of yelling, he said:
“Everyone screws up. Owning it is senior-level behavior. Hiding it is junior.”
I never forgot that. Transparency matters. So does learning from the screw-up, writing a postmortem (even if it’s just a Slack message), and figuring out how to not repeat it.
And here’s the kicker: you’re going to mess up again. Just do it better next time.
Lesson:
Accountability makes you trustworthy. The best devs I’ve worked with weren’t perfect they were honest.
Pro move: If you roll back a deploy, don’t just say “it’s fixed.” Say what happened, why it broke, and how it won’t happen again.
9. Think like a product owner
If you’ve ever shipped a feature thinking, “My job’s done, the code works,” then congrats you’ve earned a visit from the ghost of product feedback.
As devs, we love solving problems. But sometimes, we forget to ask: whose problem are we solving, and does this actually help them?
One of the biggest lessons my principal engineer hammered home was this:
“You don’t write code. You solve business problems using code.”
That hit me. Because suddenly, I wasn’t optimizing functions I was improving signup conversion. I wasn’t just patching a bug I was fixing something that stopped users from buying.
Once you start thinking like a product owner, things shift:
- You question requirements, not just implement them
- You push back on features that don’t make sense
- You propose simpler, faster solutions that still deliver the outcome
This mindset makes you dangerously valuable. It moves you from “engineer who delivers tickets” to “engineer who drives outcomes.”
Lesson:
Good devs write code that works. Great devs write code that matters.
Try this: Before you start a task, ask yourself, “What is the actual goal here?” You’ll save yourself hours and probably a sprint or two.
10. Naming is hard. do it anyway.
There’s a reason every senior dev has 10 commits named something like fix-stuff, final_final_fix, or temp-bug-bandaid. Naming things is one of the hardest problems in programming—and one of the most important.
Here’s how it usually goes:
“I’ll rename this later…”
Famous last words
Variable names like x, data1, or fooObj don’t just slow others down—they slow you down. When you're trying to debug code you wrote three sprints ago and can’t remember what res2 does... that’s naming failure.
My principal engineer had this rule:
“If it takes more than 2 seconds to guess what a name means, rename it.”
Good names are specific. They reflect intent. They remove the need for extra comments. A well-named variable or function can make a code snippet self-explanatory.
Examples:
-
data→userSubmissionPayload -
tempResult→filteredInvoicesByRegion -
doThing()→calculateNetPayAfterTax()
You’re not writing poetry. You’re writing instructions for humans and machines. Be precise.
Lesson:
Take the time to name things well. Your future self and your code reviewers will love you for it.
Bonus tip: If naming is hard, that’s a signal your function is trying to do too much. Break it up. Smaller things are easier to name.
11. Write less. think more.
In the early days of coding, I used to treat my keyboard like a machine gun spraying lines of code at problems and hoping something would hit.
Spoiler: most of it didn’t.
Then one day, during a stand-up, my principal engineer looked at my PR and said:
“This looks like you wrote first and thought later.”
Yup. Guilty.
Here’s the truth: writing more code doesn’t make you more productive. It usually just means more surface area for bugs. Real productivity comes from slowing down, understanding the problem deeply, and crafting a tight, focused solution.
Before you code:
- Draw it out
- Write pseudo-code
- Ask questions
- Think through edge cases
- Think about what happens if you’re wrong
This sounds slower. It feels slower. But it’s actually way faster long-term, because you’re not spending half a day debugging the mess you wrote in a rush.
Lesson:
Don’t treat code like a to-do list. Treat it like design. Think twice, code once.
Rule of thumb: If you’re not sure what the first line of your function should be go back and rethink the purpose of the function.
12. Learn to explain tech to non-tech people
You ever try to explain your job to someone outside tech and watch their eyes glaze over like you just started speaking Elvish?
Yeah, same.
One of the most career-defining lessons my principal engineer taught me had nothing to do with code. He said:
“If you can’t explain it simply, you don’t understand it well enough.”
Here’s the kicker: your job as a dev isn’t just to build things it’s to communicate. Whether it’s with product managers, designers, support teams, or execs, your ability to explain how and why things work makes you 10x more valuable.
Think analogies. Think storytelling. Think real-world examples.
The first time I nailed this? I explained Kafka to our marketing lead like this:
“Imagine a pizza shop. Orders go to a kitchen queue. Each chef picks the next order and makes it. Kafka is that queue, but for data instead of pizzas.”
She nodded. She got it. She actually thanked me. I almost cried.
Lesson:
Don’t gatekeep your knowledge behind jargon. Break things down. Your communication skills will take you further than your GitHub stars ever will.
Bonus: Practice writing technical blog posts, or explaining something you just built to a friend who’s not a dev. It’s a brutal but honest feedback loop.
13. Automate boring stuff, but monitor it
Every dev hits a moment when they look at a repetitive task and think:
“I should script this.”
Good. That’s how automation is born. That’s how we avoid soul death by CSV import.
But here’s what my principal engineer drilled into me:
“Automate it like a pro, but monitor it like a pessimist.”
Automation isn’t magic. It’s just fast repetition and if your logic is flawed, you’re now repeating a mistake at scale. I once wrote a cron job that quietly skipped a step in our payment pipeline. You know what happens when you skip payments?
It’s easy to feel like a hero when you slap together a bash script or webhook integration. But the real power is knowing what can go wrong and baking in logs, alerts, retries, and failsafes.
Automation without observation is just a fancy way to cause silent chaos.
Lesson:
Automate repetitive work to save your brainpower but always assume your script will fail and cover for it. You’re not lazy you’re strategically cautious.
Tip: Add alerts, logs, and clear output to your automations. If it breaks, make sure someone (preferably not a customer) finds out first.
14. Read great code like you read great books
You wouldn’t expect to write a novel without reading a few, right? Same goes for code.
One of the biggest mindset shifts I had as a developer came when my principal engineer said:
“You’ll learn more reading great code than writing bad code.”
At first, I rolled my eyes. Then I started browsing high-quality open-source repos on GitHub. Suddenly, I understood new patterns, smarter ways to organize folders, better naming conventions, more elegant tests. Stuff no tutorial ever taught me.
Reading great code gives you exposure to:
- Idiomatic patterns in real-world projects
- How pros handle edge cases, testing, and config
- The art of balancing readability with performance
And don’t just skim the files follow the commit history. See how the project evolved. Check out the PRs and review discussions. That’s where the real gold lives.
Some of my personal favs to learn from:
Lesson:
Expose yourself to well-written codebases. Don’t just code in isolation learn from the best.
Bonus exercise: Fork a popular repo and try fixing a minor issue or improving docs. It’ll humble you and teach you real fast.
15. You’re not your job title
Early in my career, I thought titles were everything.
Junior Developer. Mid-level. Senior. Tech Lead.
Each one felt like leveling up in an RPG. Like some badge of honor that would finally make me “enough.”
But titles lie. I’ve seen “senior” engineers who couldn’t write tests. I’ve seen interns ship better code than full-timers. I’ve seen quiet devs build whole systems while loud ones hogged meetings.
One day, I said something like,
“I’m just a junior, so maybe I’m wrong…”
And the principal engineer stopped me mid-sentence.“Drop the ‘just.’ You’re a developer. Own it.”
That hit different.
Your title doesn’t define your value. Your curiosity, your communication, your effort to learn and improve that’s what matters. The best devs keep learning regardless of role. The worst ones hide behind titles.
Lesson:
Detach your identity from your job title. Stay hungry, stay humble, and keep shipping value. You’re already a “real” developer.
Reminder: A title might open doors but your mindset decides how far you walk through them.
Conclusion: survive, thrive, and don’t ship on Fridays
So there you have it 15 survival lessons straight from the trenches, passed down by someone who’s burned code, built systems, mentored chaos, and lived to commit another day.
These weren’t just tips. They were mindset shifts. Culture checks. Dev philosophy. The kind of stuff that turns “someone who writes code” into someone who thinks like an engineer.
Let’s recap what made the biggest difference:
- Think systems, not syntax
- Write like someone will read it (because they will)
- Communicate like it’s your job (because it is)
- Ship with care, own your mess, and grow with grace
- Never underestimate the power of one clean log, one clear variable, or one good question
And remember:
Titles fade. Frameworks change. But curiosity? That scales infinitely.
If even one of these lessons hit you in the gut or saved you from pushing another 500-line PR without a test then mission accomplished.
Want more?
- Explore open-source projects on GitHub Trending
- Bookmark The Pragmatic Programmer
- Try writing your own dev lessons blog post. You’ll realize how much you’ve grown.
Top comments (1)
so much of this just lands for me, tbh - been on both sides of the commit shame spiral. you think the best way to keep leveling up is just reps, or something else?