Senior Software Engineer, AI Platform

Our client is a fast-growing technology company building infrastructure for the next generation of artificial intelligence. Its platform creates interactive, resettable digital environments where AI agents can explore, complete tasks, learn from failure and improve through active experience.

The company works at the intersection of software engineering, simulation infrastructure and frontier AI, collaborating closely with leading AI research organisations. Its mission is to create the training environments and data needed to develop increasingly capable AI systems.

The culture is high-trust, technically ambitious and low in bureaucracy. Curiosity, intellectual honesty, initiative, pragmatic problem-solving and a strong focus on execution are central to how the team operates.

As Senior Software Engineer, AI Platform, you will help design and build the foundational systems behind the company’s simulation and data-generation platform. This is a backend, systems and infrastructure-focused role, offering significant ownership in an early-stage, fast-moving environment.

You will architect and operate scalable APIs, backend services, data persistence layers and distributed workflows. You will develop infrastructure for capturing, processing and managing experiential data, while improving reliability, testing, monitoring, deployment and automated quality feedback loops.

Working closely with AI and curriculum engineers, you will turn ambitious or ambiguous requirements into robust production capabilities. You will lead technical design, make pragmatic architectural decisions and own meaningful systems from initial concept through delivery and operation.

The role is based in London, with an initial five weeks full-time onsite followed by a flexible hybrid model, typically around two days per week in the office.

• Senior, Staff or Principal-level backend, platform, infrastructure or systems engineering experience.
• Proven ownership of complex production systems from ambiguous problem to delivery.
• Strong system-design judgement, including architecture, interfaces, trade-offs and reliability.
• Proficiency in a typed programming language;
  Type Script/Node.js, Python, Go, Java, Kotlin or similar.
• Experience with cloud platforms such as AWS or GCP and modern deployment practices.
• Startup or scale-up experience, with initiative, technical depth and a pragmatic, low-ego approach.
• Experience with distributed systems, data-intensive workflows, Docker, Kubernetes or Terraform is advantageous.
• Ability to mentor engineers and collaborate effectively in evolving environments.

• Base salary typically £130,000–£160,000, with flexibility depending on experience and level.
• Meaningful equity participation.
• Full-time permanent employment.
• Hybrid working in London, typically around two days onsite each week.
• Initial five-week onboarding period based full-time in the office.