Senior Backend Engineer Amsterdam

Offensive Security & Agentic Attack Systems | Go, Kubernetes, Distributed Systems | €90K to €110K + stock options + unlimited time off + indefinite contract

Amsterdam
€ 110.000

Golang

Kubernetes

Kafka

Your job: Senior Backend Engineer Amsterdam

Have you been on the attacking side, through pentests, red teaming, bug bounties or serious CTF work, and do you now build backend systems yourself?
Do you want to turn that attacker's mindset into a product, instead of leaving it at the door when you open your editor?
Have you run your own code in production on Kubernetes, and do you want to do that at a scale where you actually hit the limits of the infrastructure?
Do you say yes to €90K to €110K, stock options, unlimited time off, an indefinite contract and a great office in Amsterdam?

Then this role is worth your attention.

Your future employer: offensive security where the market is still wide open

Most security budgets still go to defence: walls, alerts, detection. Only a small slice goes to looking at a company the way an attacker does, while that is exactly where many organisations are blind. Your future employer is a fast growing security scale-up that builds offensive security tooling to fill that gap, continuously showing customers how exposed they really are from the outside.

Their customers are spread across the world, and Fortune 500 companies are already on the client list. They do that with fewer than a hundred people. For you that means your work does not disappear into a large machine: what you build lands in front of security teams at some of the biggest companies in the world, and you can see the effect of it.

The company is well funded and the engineering team is about to double. That means room, not just headcount. A lot still has to be built out, and the people who join now decide how it gets built.

Your role: Senior Backend Engineer Amsterdam

They are looking for a Senior Backend Engineer who still thinks like a hacker. There is always a lot of room for your own ideas, and that is the core of the role: what else can we automate in scanning and testing, which attack paths are we not covering yet. You write an idea down, and then you build it yourself.

Right now they have the chance to work agentic AI much deeper into their systems, and that is where you can really sink your teeth in. Parts of the agentic attack system already exist, other parts still need to be integrated. The hard question is how to make agents that run multi-step attacks reliable, at scale, in production.

The data volumes are serious. The team has run into the limits of Kubernetes and the cloud vendors before. So distributed systems questions are daily work: what happens when a task runs twice, when a dependency times out halfway, when a retry is not safe, when what you know about a target quietly becomes incorrect state.

You work closely with the cloud and infra teams to get the most out of the platform, and you deploy and monitor your own code. Engineering works in guilds, and the codebase is run in an open source style, so other teams, and agents, can open pull requests and contribute. The language is Go. If you have not written much Go yet but bring the rest, you get the chance to go deep in it here.

What you bring

Real offensive security experience. Pentesting, red teaming, bug bounty, CVEs, serious CTF work: you have been on the attacking side and you can show it.
Hands-on Kubernetes experience in production. You have run real workloads on it yourself, not only deployed to it.
6+ years of professional experience, including senior backend work on distributed systems at scale
Experience operating production systems, with the battle scars to prove it
The initiative to come up with ideas, write them down and then build them

The offensive experience and the production Kubernetes experience are both hard requirements.

Nice to have, none of them a dealbreaker: