Senior Full-Stack Engineer, Cloud Platform
Description
Cyrex works with some of the world’s most demanding technology companies, from global entertainment platforms to regulated financial and healthcare infrastructure. We’re a small team, but we’ve built a client list and track record that go well beyond our size. We’re now bringing that experience into a new AI-powered product, and we’re looking for a Senior Full-Stack Engineer to own the platform around it: both the product our customers interact with and the cloud infrastructure it runs on. This is a genuinely full-stack role with meaningful infrastructure ownership. Roughly half of your work will be on the product itself: a Go backend and React frontend used directly by customers. You’ll work on the challenges that come with running a multi-tenant platform, including accounts, authentication and access, permissions, and maintaining a clear record of what happened and when. The other half is the AWS infrastructure underneath it. You’ll own infrastructure as code and help solve the operational challenges of running long-lived and asynchronous workloads reliably in production.
Some of the most interesting engineering problems sit where those two areas meet. If you’re looking for a full-stack role that stops at the API boundary, this probably isn’t it.
This is also an early role in a broader phase of growth for Cyrex. You won’t be joining a large engineering organisation with every responsibility already divided up. You’ll be helping us decide how this part of the company should be built as the product, team and customer base grow.
About You
We’re looking for an engineer who enjoys owning systems end to end, from a React component through to the IAM policy and infrastructure supporting it. You’ve built and operated production systems on AWS. Not just deployed applications to AWS, but been responsible for keeping them running and figuring out what went wrong when they didn’t. You’re comfortable treating infrastructure as code as the default way infrastructure gets created and changed. You understand asynchronous and distributed systems in practice. Queues, retries, idempotency, and recovering long-running jobs from partial failures aren’t just concepts you’ve read about, they’re problems you’ve had to solve. You write backend code with the expectation that someone else will need to understand it a year from now. You care about clear boundaries and maintainable systems, and you know what happens to a codebase when those things are ignored. You’re also comfortable building a clean, functional frontend without needing every detail handed to you by a designer, even if frontend development isn’t your favourite part of the stack. We work spec-first: meaningful changes are proposed, discussed, and agreed in writing before they’re built. If you see that as an unnecessary process to work around, we probably won’t be a good fit. If you appreciate having clarity before implementation begins, you’ll likely feel at home here. You don’t need to be a security specialist, we already have plenty of that expertise on the team. You do need to be curious about the domain and naturally rigorous in how you work. We operate in a field where systems need to be accountable for what they do, and that influences how we design and build them. The stack Backend: Go, PostgreSQL Frontend: React, TypeScript Infrastructure: AWS, infrastructure as code, containers Elsewhere at Cyrex: Python, which you may occasionally work with
Requirements
- 5+ years of experience building production software, with meaningful ownership of what you shipped.
- Strong production experience with Go. This is important: we need someone who can contribute effectively to the existing codebase from the start rather than learn Go on the job.
- Hands-on AWS experience beyond using the console, including infrastructure as code, containers, IAM, and networking.
- Experience designing and operating asynchronous and distributed systems, including handling their real-world failure modes.
- Enough frontend experience to confidently build and own a clean React interface.
- Solid working knowledge of PostgreSQL, including thoughtful schema design.
- Excellent written English. We write things down before we build them, and written communication is an important part of how decisions are made.
- Experience with multi-tenant SaaS, Python, or the security industry is useful, but none of these are requirements.
Benefits
- The opportunity to join Cyrex at an important point in its growth, as we expand the team, invest in our own products, and push further into AI-driven security testing.
- The chance to work in a fast-moving environment with the ambition to operate at the frontier of how AI is applied to real-world security testing.
- A platform early enough that your decisions will shape how it develops and scales.
- Room to grow with the company. As the product and engineering team expand, there will be opportunities to take on broader technical ownership, shape how we work and grow into technical or team leadership depending on your strengths and ambitions.
- Genuine ownership of an entire technical layer rather than a queue of isolated tickets.
- Direct access to founders and leadership, with decisions made in days rather than quarters.
- Hybrid working from Athens.
- Competitive compensation with straightforward, regular reviews.
- A small, multicultural team today, with the opportunity to play a meaningful role in what it becomes next.