From Developer to Penetration Tester — My Journey and What I Learned
From Developer to Penetration Tester — My Journey and What I Learned
TLDR: I spent a decade writing software before I ever thought seriously about breaking it. The shift from developer to penetration tester wasn't a clean pivot — it was gradual, humbling, and genuinely one of the best decisions I've made. This is my honest account of how that happened, what I wish I'd known earlier, and why everything eventually led to starting Kuboid Secure Layer.
Where I Started — Ten Years of Development
I wrote my first real application at school — a basic web app that I was embarrassingly proud of. It had some authentication, no input validation, and almost certainly a handful of SQL injection vulnerabilities that I wouldn't have been able to name at the time.
That was fine, because nobody taught me otherwise. I was a self learner, I only knew about algorithms, data structures, databases, and system design. Security was an occasional footnote, never a module. I graduated, joined a development team, and spent the next decade building web applications, APIs, and backend systems across a few different industries.
I was good at it. I shipped features. I met deadlines. I wrote code that worked. And like most developers operating inside that system, I thought about security the way most people think about their money stolen — you know it matters, you assume someone is handling it, and you don't think about it until something goes wrong.
The Moment That Changed My Perspective
About four years into my career, a colleague mentioned he'd been playing CTFs — Capture The Flag competitions — in his spare time. Security challenges, basically. Find the vulnerability, exploit it, get the flag. I assumed it wasn't for me. I wasn't a "security person."
He sent me a beginner challenge anyway. I spent two hours on it before I got it. And in those two hours, I saw a web application — the kind I built professionally — from a completely different angle. Not "how do I make this work?" but "how could someone make this fail?"
That question didn't leave me alone.
I started working through platforms like HackTheBox and TryHackMe in the evenings. Then I found a bug bounty programme — a legitimate way for security researchers to find and responsibly report vulnerabilities in real applications in exchange for recognition or payment. I saw a vulnerability in action where a user could view another user's private data by changing a numeric ID in the URL.
I had written that exact pattern a dozen times in production code. Never imagined it as an attack surface.
What Development Taught Me About Security
Here's what I didn't expect: my decade as a developer wasn't a detour. It was preparation.
I already understood how applications were built — how authentication flows worked, how data was passed between frontend and backend, how APIs were structured, how databases were queried. When I started looking at applications as an attacker, that context was enormously valuable.
Most vulnerabilities don't live in exotic places. They live in the decisions developers make when they're under pressure, working with unclear requirements, or reusing patterns they learned from someone else who was also under pressure. Because I had made those decisions myself — in production, at scale — I understood intuitively why a vulnerability existed, not just that it existed. That made me significantly better at finding them, and significantly better at explaining them to the teams I was eventually testing.
The developers I worked with trusted me differently once they knew my background. I wasn't someone who had never shipped a line of production code telling them they'd done it wrong. I was someone who had done it the same way and had then learned why it mattered.
What Transferred Directly — and the Gaps I Had to Fill
The skills that transferred immediately: reading and understanding code across multiple languages, thinking systematically about application architecture, understanding business logic well enough to spot where the logic could be abused, and communicating technical findings clearly to non-technical stakeholders.
The gaps were real, though. Networking fundamentals — TCP/IP, DNS, how traffic actually moves across infrastructure — I had worked above that layer for most of my career and had to build it properly from scratch. Active Directory and Windows enterprise environments were largely foreign to me as someone who had worked predominantly in web and Linux environments. And the offensive security mindset itself — thinking adversarially, persistently, creatively — is genuinely a skill that takes time to develop. You don't just read about it and acquire it. You practice until it becomes instinctive.
I studied for cyber security and various certification which I'd describe as the most demanding and most rewarding learning experience of my professional life. It filled most of the gaps that my development background had left.
Why a Developer Background Makes a Better Security Tester
I'm biased, obviously. But I've worked alongside security professionals who came from pure security backgrounds and those who came from development, and there is a real difference in how each approaches an engagement.
A developer-turned-tester reads source code during a review the way a native speaker reads prose — quickly, with instinct, catching things that feel wrong before they can articulate why. They understand build pipelines, deployment environments, and the decisions made under deadline pressure that leave vulnerabilities behind. They think about what a feature was trying to do, which is often the key to understanding how it can be abused.
More practically: when a developer-turned-tester writes a finding report, the remediation guidance is grounded in how code actually gets written and shipped. It's specific. It's implementable. It doesn't read like it came from someone who has never opened a pull request.
What Starting Kuboid Secure Layer Means
I started Kuboid Secure Layer because I kept seeing the same gap: businesses that had invested in good technology and good people, but had no structured way to understand whether their applications and infrastructure were actually secure. Not "we ran a vulnerability scanner" secure. Actually secure.
The firms doing this work well were either too expensive for early-stage companies or were running compliance-focused engagements that produced impressive-looking reports and very little practical change. I wanted to build something different — a practice that worked closely with development teams, communicated clearly with business leadership, and focused on findings that could actually be acted on.
That's what Kuboid is. It's the company I would have wanted to work with at every stage of my development career, before I knew what I didn't know.
We're early. I'm documenting the process of building it — the clients, the engagements, the lessons — honestly and publicly. If you want to follow along, the blog is the right place to do that. If you want to understand what we actually do, the services page is a good starting point. And if you have a product or codebase you're not sure about, let's talk.
Final Thought
I don't think my path from developer to pen tester was the fastest or the most efficient. But I think the decade I spent building things made me substantially better at breaking them — and, more importantly, at helping the people who build them understand why security isn't a separate concern but a built-in one.
If you're a developer reading this and the idea of looking at applications from the other side has ever crossed your mind — start with a CTF. The curiosity it surfaces might surprise you.
Kuboid Secure Layer is a cybersecurity practice built by practitioners, for businesses that take security seriously. Learn more at www.kuboid.in or read more on our blog.