Principal Software Engineer (Platform)

Principal Software Engineer, Platform

📍Remote (UK/Ireland) - Citizenship/Settled Status/ILR Required

💷Up to £90k

Imagine the marketing team, finance and ops all shipping their own software with AI. Someone has to build the platform that lets them do it safely and at scale. That’s this role.

Our client is a global payments technology company. They’re building an internal platform across AWS, Azure, GCP and their own data centres. Your users are engineers and AI agents. You’ll judge your success by how many tickets nobody needs to raise anymore.

What you’ll be doing

• Designing API first platform services for compute, networking, identity, secrets and delivery
• Building control planes that drive DNS, load balancers, firewalls and cloud through their APIs
• Building MCP servers and agent tooling with tight scoping, authentication and full audit
• Writing policy as code (OPA, Sentinel) and durable workflows in Temporal
• Building the developer portal engineers actually want to use
• Setting the engineering standards for the team. You’ll still write code every week, and you’ll own what you build in production

What you’ll bring

• Senior or lead experience building and running production services
• Expert level in C#, Java, Go or Rust, plus working TypeScript
• Strong API design: REST or gRPC, OpenAPI, OAuth 2.0 / OIDC
• Solid infrastructure knowledge: DNS, TLS, load balancing, networking, Terraform, containers
• Daily hands-on use of agentic coding tools (Claude Code, Cursor, Codex), with real shipped work to show for it
• Bonus points for Temporal, Vault, Consul, Backstage, Cloudflare Workers or custom Terraform providers

Why it’s worth a conversation

• Real ownership, without the red tape you’d get at a hyperscaler
• Fully remote, with flexible hours and no micromanagement
• Generous annual leave, private health insurance and a 5% pension
• £500 home office setup budget plus a monthly WFH allowance
• Hackathons, summer and Christmas meetups, and a paid volunteering day

You’ll need to be based in the UK or Ireland and already have the right to work there. Visa sponsorship isn’t available.

Research indicates that men will apply to a role when they only meet 50-60% of the descriptions, however, when looking at women and other minority groups, they can look for up to a 99% match in order to apply to a role. If you feel you are a fit for our role, please still apply, don’t worry if you don’t tick every single box. We’d still love to hear from you. We encourage underrepresented talent to apply to all our roles & support accessibility needs