Software Engineer (Rust) in London

About hyperexponential (hx)

At hyperexponential, we are building the AI-powered platform that enables the world’s most critical decisions in a $7 trillion industry. Our platform brings together data, AI, and human expertise to give insurers the fastest path from submission to decision.

About the Kernel team

The Kernel team sits at the core of hx’s platform, building the execution engine that underpins how customer models are evaluated, validated, and run safely at scale. Their work directly enables hx Renew and future products to make correct, performant, and explainable decisions in high-stakes environments.

As a Software Engineer in the Kernel team, you will own meaningful parts of this critical system end to end, contributing production code, improving architecture, and partnering closely with adjacent teams to ensure the engine meets real product and customer needs.

What you’ll be doing:

• Designing and delivering backend features in the Kernel execution engine that improve correctness, performance, and reliability for customer model runs at scale.
• Strengthening a clean, modular Kernel architecture that is easy to understand, test, and safely evolve over time.
• Building automated tests and observability for complex execution scenarios, enabling faster detection, diagnosis, and resolution of production issues.
• Partnering with adjacent engineering teams to shape Kernel behaviour and interfaces, providing clear technical input and following through to delivery.
• Owning work from design through rollout and monitoring, balancing immediate product needs with long-term system sustainability.
• Demonstrating hx values by proactively identifying risks, collaborating constructively, and taking full accountability in a critical core-platform area.

What you’ll need to have done:

• Built and shipped backend systems in a polyglot production environment, working across languages such as Rust, Python, or C/C++, and choosing the right tool for the problem.
• Either used Rust in production systems, or demonstrated strong systems experience in C/C++ or Python with clear evidence of learning and adopting new languages quickly.
• Delivered backend features where correctness, performance, and resource efficiency were critical, and improved systems based on real production behaviour.
• Applied solid systems thinking around execution, concurrency, and memory or resource management in real-world backend services.
• Designed and implemented effective testing and observability that made complex backend behaviour understandable, debuggable, and safe to evolve.
• Owned work end-to-end from design through rollout, monitoring, and iteration, collaborating closely with peers and raising risks early.

You’re unlikely to thrive here if:

• You prefer highly predictable work and feel uncomfortable operating in ambiguous, evolving problem spaces.
• You optimise for shipping quickly at the expense of correctness, maintainability, or long-term system health.
• You avoid ownership of outcomes beyond your immediate code changes.

Compensation

At hx, we are committed to salary transparency. You’ll always have clarity on pay early in the process.

Benefits:

• £5,000 training and conference budget for individual and group development.
• 25 days of holiday plus 8 bank holidays (33 days total).
• Company pension scheme via Penfold.
• Mental health support and therapy via Spectrum.life.
• Individual wellbeing allowance via Juno.
• Private healthcare insurance through AXA.
• Income protection and Life Insurance.
• Cycle to Work Scheme.

Additional perks:

• Top-spec equipment (laptop, screens, adjustable desks, etc.).
• Regular remote and in-person hackathons, lunch and learns, socials, and game nights.
• Team breakfasts and lunches, snacks, drinks fridge, and a fun office at The Ministry.
• Exceptional opportunities for personal development and growth.

Interview process:

• Initial call with Talent team (30 minutes)
• Manager Interview (60 minutes)
• Technical Assessment (e.g., code review, system design) (120 minutes)
• Values Interview with Tech Leadership (60 minutes)
• Offer

Our commitment to Diversity:

hxers are at the centre of everything we build. We are committed to creating an environment where everyone can thrive, grow, and make an impact.

If you’re energised by complexity and motivated to grow, we encourage you to apply and join our global team.

Next steps:

If this opportunity resonates with you, we encourage you to apply or share it with your connections!