Principal Software Engineer

Principal Software Engineer (Data Platforms / APIs) London | Full-time | High-Scale Data Infrastructure We’re working with a global digital asset and market data group operating at the intersection of financial markets, crypto, and institutional-grade data platforms . This business powers real-time market data, indices, and analytics used by institutional clients worldwide. The engineering challenge is non-trivial: billions of requests per month , always-on systems, and zero tolerance for downtime or inaccurate data. They’re now hiring a Principal Software Engineer to own the technical direction across their core data platforms and APIs . This is a senior, hands-on IC leadership role . You’ll set architectural direction, solve problems, and raise the technical bar across teams. What You’ll Be Doing: Owning and driving the long-term technical roadmap across high-scale data services (REST APIs, streaming, WebSockets, client-facing platforms) Designing and evolving resilient, high-throughput distributed systems operating 24/7 Acting as the technical escalation point for complex, cross-team challenges (resiliency, uptime, architectural change at scale) Mentoring senior engineers on architecture, trade-offs, and operational best practice Leading platform-wide improvements in observability, testing strategy, and developer tooling Making pragmatic build vs buy decisions for core data and infrastructure components What You’ll Bring: 8+ years’ backend engineering experience, with time operating at Staff or Principal level Deep experience designing, building, and running large-scale distributed systems Strong understanding of synchronous and asynchronous architectures (REST, streaming, event-driven systems) Experience supporting high-availability, global, always-on platforms , ideally in financial or data-heavy environments Strong production experience with Node.js or Go Solid database fundamentals (PostgreSQL, Redis, performance tuning) Strong DevSecOps mindset: CI/CD, infrastructure-as-code, monitoring, logging, tracing Ability to influence senior technical and non-technical stakeholders without formal authority Nice to have: Cloud-native architecture (Azure or GCP) Kafka or similar event-streaming platforms Kubernetes / Docker Observability tooling (Datadog, Prometheus, OpenTelemetry) Exposure to market data, financial systems, or regulated environments What’s On Offer: £150,000 – £175,000 base salary 25% Bonus of base salary Share Scheme High ownership, real technical influence, and problems that genuinely matter This is a rare opportunity for a senior engineer who wants to define architecture and own outcomes , not maintain legacy decisions. 💬 Apply via LinkedIn or message directly for a confidential conversation.