Your Job Isn’t Just Writing Code. It’s Proving It Works
Hands-on technology leader with 10+ years building scalable, mission-critical systems at Goldman Sachs, Brevan Howard and fast-growing fintechs. Expert in cloud-native architectures, distributed data pipelines and high-throughput systems; experienced in migrating legacy platforms and designing AI-enabled services. Proven track record delivering reliable platforms that process millions of transactions daily.
Software development isn’t about churning out lines of code and hoping they work. Anyone can generate code, even AI does that now. What separates the pros from the amateurs is this:
✅ Your job is this: Deliver code you have personally verified works
No ifs, no maybes, no “let reviewers find the bugs.”
😬 The Problem Today
We’ve all seen it: a huge AI-generated pull request lands with no evidence that it actually works. Someone else, usually a reviewer or maintainer, has to chase down bugs, figure out if it even runs, and fix it. That’s not teamwork, that’s dumping your mess on someone else.
That used to be forgivable. Today? There’s no excuse.
🧠 Real Software Engineering = Proof
A real engineer doesn’t just hope code works. They prove it. There are two essential steps every time:
1️⃣ Manual testing first
You must see your code do the right thing yourself.
Run it
Try it
Break it
If you haven’t seen it actually work with your own eyes, it might as well be imaginary.
A smart trick: capture a terminal log or short screen recording that shows your change working and include that in your pull request.
2️⃣ Then write an automated test
Tests are your safety net, they prove your change still works tomorrow, next month, and after someone else touches it.
Modern tools make this easier than ever. Skip this only if you love bugs.
Manual testing + automated tests = Proof.
🤖 Even If AI Wrote the Code
Yes, modern coding assistants like Claude Code and Codex CLI can write and test code for you. But that doesn’t mean you can trust them blindly.
You still need to:
Teach the tool to show it tested the code.
Understand the test results.
Add proper automated tests to your repo yourself.
In other words: AI assists, you’re responsible.
💡 Why This Matters
Submitting unproven code:
Wastes reviewers’ time
Introduces hidden bugs
Shifts the real work to someone else
Proving your code works:
Saves time
Builds trust
Makes you a stronger engineer
It’s not optional. It’s the real definition of professional software development in an AI-augmented world.
🔥 TL;DR: The New Rules of Quality Code
✔ Run your code yourself
✔ Show it works
✔ Add automated tests
✔ Don’t submit anything unless it’s proven
Treat your evidence of working code like gold. Anyone can write lines you prove results.
Source: https://simonwillison.net/2025/Dec/18/code-proven-to-work/