Software Engineer - Backend (up to £160k)

Dex; Greater London; On-site; GBP 90,000 - 135,000; Full time

Job summary

Dex is seeking a backend engineer to join a project that builds fault-tolerant systems for real-time defence intelligence. You will design and implement features for a mission-critical Rust/Python stack, focusing on reliability, latency, and robust testing in high-stakes environments.

You will work with a team that values rigorous RFC processes, code reviews, and genuine ownership of distributed systems, including edge computing and untrusted networks.

Qualifications

• Experience building backend systems in real-time or embedded contexts.
• Strong knowledge of distributed systems and fault tolerance.
• Experience with Rust or similar language is preferred.

Responsibilities

• Design and implement features for a mission-critical backend.
• Engineer for extreme conditions: intermittent connectivity and embedded systems.
• Ensure robustness through testing and benchmarking.
• Contribute to a Rust/Python-based stack and learn from open-source contributors.
• Address complex distributed systems problems with failure modes as the baseline.

Skills

Backend in Rust/Go/Java

Distributed systems

Edge computing

REST/GraphQL/gRPC

Tools

REST

GraphQL

gRPC/Protobufs

Arrow

Job description

This role is with one of Dex's trusted partner companies. We work closely with their teams to truly understand their culture, goals, and what they're looking for, so we can match you with the right opportunity and give you context about the role before you commit to a process.

The role

This company builds AI software for real-time defence intelligence. Their systems operate on semi-autonomous platforms, turning raw sensor data into actionable insights. The backend infrastructure faces extreme constraints: intermittent connectivity, embedded compute, low-bandwidth radios, and air-gapped networks where trust is never assumed. They're backed by leading investors and are one of Europe's fastest-growing companies.

You'll join a team where reliability isn't a feature, it's the product. Your code will run in high-stakes environments, directly impacting people in critical situations. This isn't about scaling typical web services; it's about engineering robust, fault-tolerant systems for the most challenging operational contexts. Expect a culture built on rigorous RFCs, code review, and a shared commitment to unblocking colleagues.

The work

• Design and implement features, algorithms, and infrastructure for a mission-critical backend.
• Engineer for extreme conditions: intermittent connectivity, resource-constrained embedded systems, and untrusted networks.
• Ensure system robustness and reliability through comprehensive testing and benchmarking.
• Contribute to a Rust and Python-based stack, with opportunities to learn from prominent open-source contributors.
• Solve complex distributed systems problems where partial degradation and failure modes are the default.

What You Bring

• Strong backend development experience in a systems language (Rust, Java, Go, C++, or similar).
• Proven ability to build and operate complex distributed systems, with a focus on failure modes.
• Deep expertise in at least one area: edge computing, latency optimization, or platform engineering.
• Familiarity with backend interface tools like REST, GraphQL, gRPC/Protocol Buffers, and Arrow.

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