Principal Software Engineer

Principal Platform Engineer

FULLY REMOTE ACROSS UK AND IRELAND

Our client is a fast-scaling fintech building the next generation of payment infrastructure. They're merchant-first, engineering-led, and genuinely obsessive about outcomes over process. Small teams, real autonomy, hard problems.

They're hiring a Principal Platform Engineer to own the design and delivery of a suite of Model Context Protocol (MCP) servers - the trusted, governed gateway between AI agents and their core payments platform.

This is a hands-on principal role. You'll set technical direction and write production code, not just review it.

What you'll be doing:

• Owning the architecture and delivery of MCP servers that expose platform data and capabilities to AI agents and internal developer tooling
• Designing the transport and session model (Streamable HTTP), including stateful sessions for progress streaming, subscriptions, sampling, and user elicitat...