Platform Engineer in London

About Saturn

Saturn is a Series A, Y Combinator-backed startup building the AI-native operating system for the £100B+ financial advice industry. We believe advice will always be human, and we build technology that makes human advisers extraordinary. Advisers currently lose up to 70% of their time to administration and compliance. Saturn automates this, giving advisers back their most precious resource so they can focus on what they do best: serving clients. We are compliant by design, trusted by 500+ firms and 3,000+ advisers across the UK. Our engineers are early and founding team members from Cred, Postman, Gojek, and Slice. We are a small team that orbits together, moves with purpose, and holds a high bar.

About The Role

We are focused on deepening Saturn’s position as the indispensable OS for advice firms and building the infrastructure foundation that will power the next phase of scale. That means moving from fast and working to fast, working, and bulletproof. As a Platform Engineer at Saturn, you are a backend engineer with strong fundamentals who builds the systems that everything else depends on. You design and own core financial services infrastructure: data pipelines, integrations with back-office and adviser platforms, and the reliable, secure services that underpin Saturn’s compliance and workflow engine. You think in systems, obsess over correctness and reliability, and are energised by the challenge of building infrastructure that has to be right every time.

What You Will Do

• Design, build, and maintain scalable backend infrastructure and internal platforms in Go, TypeScript and Python, the foundation Saturn’s adviser-facing products run on.
• Own reliability, performance, and observability of Saturn’s core services: data ingestion pipelines, AI/LLM infrastructure, compliance automation engines, and user-facing APIs.
• Build highly reliable, fault-tolerant services that handle sensitive financial data with the correctness and auditability that a regulated environment demands.
• Manage and scale Saturn’s AI infrastructure: LLM API integrations, ML pipelines, prompt management systems, and the proprietary compliance rule engine from our ATEB acquisition.
• Integrate with third-party financial platforms, back-office systems, and data providers, building robust, well-tested connectors that form Saturn’s system of record.
• Contribute to architectural decisions as Saturn scales across the UK market and expands internationally, with a particular focus on system correctness, data integrity, and security.
• Bring strong engineering fundamentals to every problem: well-tested, maintainable code, clear data models, and systems that degrade gracefully under pressure.
• Maintain strong documentation and champion operational excellence across the engineering culture.

What You Will Need

• 3–4 years of experience building backend systems in production, ideally in fintech, payments, or other data-critical environments.
• Strong hands-on experience with Go and TypeScript.
• Solid understanding of cloud infrastructure (AWS preferred) and how to deploy and operate backend services reliably at scale.
• Experience designing systems that handle sensitive financial or regulated data, with a strong appreciation for data integrity, auditability, and correctness.
• Strong grasp of distributed systems, event-driven architecture, and building fault-tolerant services that have to work every time.
• Experience building integrations with third-party APIs, financial platforms, or back-office systems is a strong plus.
• Strong systems-level thinking: you understand how changes ripple across a complex, integrated platform.
• Clear communicator who writes well, asks sharp questions, and collaborates effectively across disciplines.
• Prior fintech, regtech, or regulated industry experience is a strong plus.

Our Values

We care deeply about the culture we build. We hire people who are obsessed with doing great work, who seek truth over comfort, who earn trust rather than assume it, and who succeed and fail as one team.

What We Offer

• Competitive salary benchmarked to your experience and the London market.
• Equity / stock options, a genuine stake in Saturn’s success.
• On-site in our London office.
• Work on genuinely hard infrastructure challenges at the intersection of fintech, regulation, and AI.
• High ownership and autonomy, you are building the foundation of a company with a path to 50x revenue growth.
• A tight-knit, ambitious team that cares deeply about engineering quality and each other.