Senior Software Engineer - AI Platform

Senior Software Engineer – AI Platform - London, or Paris - Hybrid - £100-200k The Opportunity My client is a fast-growing AI technology company building infrastructure that helps enable the next generation of advanced AI systems. They are developing interactive digital environments where AI agents can navigate software, complete tasks, learn from failure and improve through experience. These environments generate the experiential data required to train increasingly capable AI models. They are looking for a Senior Software Engineer to join the team and help design and build the foundational platform supporting their simulation and data-generation systems. This is a highly hands-on engineering role with significant ownership. You’ll be working on technically challenging problems where requirements are not always fully defined, so you’ll need to be comfortable understanding the problem, deciding what needs to be built and taking it through to production. What You’ll Be Doing Design, build and own core systems supporting AI simulation and data generationBuild scalable APIs, backend services and robust data persistence layersDevelop infrastructure for capturing, processing and managing large volumes of experiential dataWork across distributed workflows, automation and complex data pipelinesTranslate ambitious and sometimes ambiguous requirements into practical engineering solutionsImprove reliability, testing, monitoring and deployment practicesWork closely with AI-focused engineers to productionise new capabilitiesOwn meaningful technical problems from initial concept through to productionMake pragmatic engineering decisions balancing speed, reliability and long-term maintainability What We’re Looking For You’ll be an experienced, hands-on software engineer who is comfortable taking ownership of complex technical problems. Ideally, you’ll have: Strong experience building and operating production software systemsExcellent system-design fundamentalsExperience across backend, platform, infrastructure or data-intensive engineeringStrong proficiency in at least one typed programming languageExperience with AWS, GCP or another major cloud platformExposure to Infrastructure as Code and modern deployment practicesEvidence of personally owning significant projects, platforms or systemsThe ability to work effectively where requirements are evolving or ambiguousA pragmatic and collaborative approach to engineeringThe initiative and perseverance required within a fast-moving technology environment Technology The primary stack includes TypeScript and Node.js, although direct commercial experience with this exact stack isn't essential. Strong engineers coming from Go, Java, Kotlin, Rust, C#, C++, Scala or other typed programming ecosystems are also encouraged to apply. Particularly Interesting Experience Any of the following would be advantageous: Distributed systems or high-volume data processingDocker, Kubernetes or TerraformDeveloper platforms, internal tooling or developer-experience productsApplications involving LLMs or AI agentsAutomated testing, evaluation or engineering feedback loopsEarly-stage startup or rapidly scaling technology environmentsMentoring engineers or helping raise engineering standards The Environment This role will suit an engineer who enjoys building new systems rather than simply maintaining mature ones. You should be comfortable operating where the answer isn't immediately obvious and prefer owning outcomes rather than simply completing tickets. You'll be joining an ambitious, fast-moving engineering environment with a high level of autonomy and the opportunity to influence foundational technical decisions while the platform is still evolving. The role also offers the opportunity to work on technology contributing directly to the development of advanced AI systems, alongside a competitive package and meaningful equity. Senior Software Engineer – AI Platform - London, or Paris - Hybrid - £100-200k