Principal Software Engineer, Global Public Sector (AI)

Location: London, UK; travel to client sites may be required.

Company

Scale AI develops reliable AI systems, high-quality training data, and full-stack technologies for enterprises and governments building and deploying AI applications.

What you will do

• Take on the hardest technical problems across public-sector programmes and unblock projects with unclear paths forward.
• Lead early client engagements by scoping problems, shaping proofs of concept, and defining focused approaches to demonstrate value.
• Build AI agents, evaluation pipelines, data systems, and knowledge systems; take the strongest prototypes into production.
• Define secure, cohesive, and reusable technology architectures across clients and contribute reusable capabilities to the core platform.
• Mentor engineers through pairing, design reviews, and code reviews while raising engineering standards.
• Partner with Directors, VPs, and client executives on high-stakes technical and business trade-offs, including travel to client sites.

Requirements

• Bachelor’s degree in Computer Science, Mathematics, or a related quantitative field, or equivalent practical experience.
• 10+ years of post-graduation engineering experience with proficiency in Python, TypeScript/JavaScript, Java, or C++.
• 5+ years applying AI/ML in production, including generative or agentic AI applications, RAG systems, or evaluation pipelines.
• Strong problem-solving ability and experience taking ambiguous early-stage problems from a blank page through prototype and production.
• Deep expertise in system design and architecture, including cloud-based machine learning tools and platforms such as AWS, GCP, or Azure.
• Experience mentoring engineers and raising the technical bar of a team or organisation.
• Comfort working directly with client engineering teams and senior executives.
• Excellent written and verbal communication skills for cross-functional collaboration.

Nice to have

• Forward-deployed engineering experience.
• Startup experience, particularly as a founding engineer.
• Experience building and deploying large-scale AI solutions.
• Experience delivering technology programmes for governments or regulated industries.
• Experience deploying solutions on-premises or in customer-controlled environments.
• Current or previous UK government security clearance, such as SC or DV.

Culture & Benefits

• Work in a rapidly expanding Global Public Sector team focused on AI applications for public services.
• Contribute to an inclusive and equal-opportunity workplace committed to reasonable accommodations.
• Work involves close collaboration with industry leaders, governments, and public-sector organisations.
• Candidates must wait 90 days before being reconsidered for the same role.