Senior Backend Engineer – Product Team - £100 000 plus equity

You'd thrive on building distributed systems that matter. Not the kind that serve AI cat photos and videos, we're talking about the kind that protect countries from escalating cyber warfare.

You're about to optimise for national security, working at the rare intersection of AI and cybersecurity, building distributed systems that NATO countries depend on to defend against malicious threats.

What You'll Build

You'll design the core backend services powering large-scale binary analysis systems that process 200,000 binaries daily — and then scale that to millions and beyond. UK and US defence organisations are already using what you'll build out further and deeper.

The technical challenges are the kind most engineers may never encounter: distributed systems across hundreds of nodes and thousands of CPUs, PostgreSQL databases with 500 million entries where traditional queries break down, and air-gapped deployments in private clouds for classified defence customers.

You'll work with custom transformer AI models that fundamentally understand software at the binary level, using Python, FastAPI, Celery, Redis, RabbitMQ, PostgreSQL, and Kubernetes to transform cutting-edge AI research into production systems that process hundreds of gigabytes of data daily.

You'll Be Responsible For

• Designing backend services and APIs that handle hundreds of gigabytes of data daily
• Building asynchronous processing pipelines for high-throughput, data-intensive workloads
• Solving distributed systems challenges: eventual consistency, failure modes, and performance bottlenecks at scale
• Partnering with AI researchers and security specialists to "productionise" cutting-edge deep analysis capabilities
• Contributing to system architecture decisions that shape the platform's future

Who You Are

You have 5+ years building distributed, cloud-native systems in production. You understand asynchronous Python, message queues, and how to make databases perform when they hit hundreds of millions of rows. You thrive on autonomy, taking high-level problems and delivering working solutions without hand-holding.

Must-haves: Strong Python with async frameworks (FastAPI or similar), experience with Celery/Redis/RabbitMQ, PostgreSQL expertise, Kubernetes operations, ability to obtain UK security clearance (SC level).

What's On Offer

• Salary: £100,000 + share options in a growing AI cybersecurity company
• Benefits: Top-tier private healthcare, pension, training budget, conference attendance, extra birthday leave
• Flexibility: Hybrid - 3 days a week in King's Cross + 30 days work-from-anywhere per year
• Progression: Opportunities to grow into principal architect or engineering manager roles as the company doubles in size

If you're back in your skills as a problem solver who wants your work to directly contribute to national security (NATO members), this could be your role.

Note: Security Clearance will be required, a minimum of 3 to 5 years of UK residency is required. Applications from outside of UK will not be reviewed. 

Email mark@seekr.inc with the email titled "Secure me that role" with your CV to get to the front of the Q.