Software Engineer - Backend (up to £160k)

Dex; Greater London; On-site; GBP 80,000 - 120,000; Full time

Job summary

Dex, in partnership with a leading defence-tech company, seeks a backend-focused engineer to design and build a mission-critical backend stack. You will tackle extreme operating conditions, including intermittent connectivity and air-gapped networks, using Rust, Python, and other systems languages.

The role emphasizes reliability, testing, and robust architectural decisions in high-stakes environments. You will work with a Rust/Python-based stack, improve fault tolerance, and learn from top

Qualifications

• 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.

Responsibilities

• 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.

Skills

Rust

Java

Go

C++

Distributed systems

Edge computing

Latency optimization

Platform engineering

Tools

REST

GraphQL

gRPC/Protobuf

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.