Principal Software Engineer – Software Supply Chain Security

Location: United Kingdom (Remote)

Salary: £135,000 – £145,000 + Equity

Benefits: 35 Days Annual Leave, 8% Matched Pension, Private Healthcare, Private Dental, Vision & Physio, Income Protection, Life Insurance, EV Vehicle Scheme, High Performance Home Office Setup.

The Opportunity

Runtime is partnering with a fast-growing, well-funded SaaS company building mission-critical infrastructure for software supply chain security. They help engineering teams manage artifacts and secure their pipelines at scale – trusted by organisations shipping software to millions of developers worldwide. Backed by top-tier investors and on a clear growth trajectory, this is a company solving a problem that’s rapidly becoming non-negotiable for every serious engineering org.

We’re hiring a Principal Software Engineer to help set technical direction for their trust and security platform – a high-leverage, hands-on role for someone who wants real architectural ownership, not just a senior title.

The Role

You’ll lead the technical direction of the systems that turn security data into policy, trust, and visibility for customers – the pipelines and platform that let engineering teams ship with confidence, knowing exactly what’s in their software and where it came from. You’ll own key architecture decisions, set the technical bar across the team, and act as a multiplier through mentorship and design leadership.

What you’ll do

• Own the architecture of core policy and data-pipeline systems that power the platform’s security capabilities
• Design for high-fidelity data ingestion feeding automated policy enforcement, at global scale
• Set the standard for reliability, performance, and engineering rigor across the team
• Drive technical decisions, not just implement them — shape direction alongside product and leadership
• Mentor senior engineers through code review, design docs, and hands-on guidance
• Represent engineering in high-stakes conversations with customers and partners

What they’re looking for

• 8+ years building, testing, and operating complex distributed systems in production, with demonstrated Staff/Principal-level technical leadership
• Strong experience with Python (Django preferred); Golang or Rust a plus
• Deep AWS experience (Lambda, ECS, Postgres, Kafka, Terraform, and similar)
• Familiarity with supply chain security concepts – vulnerability scanning, policy-as-code.
• Comfort setting direction under ambiguity in a fast-moving, still-being-defined problem space
• Excellent communicator, able to bridge technical and non-technical stakeholders