Principal Software Engineer
Legal Tech | AI-First Platform
£110,000 – £150,000
Our client is a legal tech company building an AI-first platform that helps lawyers do better work, faster. This isn’t a “bolt-on chatbot” or a thin AI wrapper around legacy workflows — it’s a ground-up rethink of how legal work should be done in an AI-native world.
Uniquely, they operate both as a regulated law firm and a technology company. That combination creates engineering challenges you don’t see every day: high-stakes, highly regulated users; complex domain logic; and real-world consequences if things go wrong. If you enjoy building serious software for serious users, this is a rare opportunity.
The role:
As a Principal Software Engineer, you’ll play a critical role in shaping both the technical direction of the product and how the engineering team works. This is a hands-on role for someone who enjoys building, but also wants to influence architecture, standards, and long-term decisions.
You’ll work closely with designers, product managers, AI researchers, and other engineers, owning features end-to-end — from early discovery and design conversations through to production and iteration.
Some days will be deep, focused coding. Others might involve:
Reviewing and shaping technical proposals
Pairing with other engineers
Observing how real legal teams use the product
Showcasing work and sharing learnings with the wider team
You’ll have a high degree of autonomy and trust, and your decisions will directly shape a product used in real legal matters.
You will be:
Designing and building high-quality, scalable features across the stack
Owning complex problems from concept to production
Influencing architecture, patterns, and engineering best practices
Working closely with product, design, and AI teams to turn ideas into real, usable tools
Balancing speed with correctness in a regulated, high-impact environment
Helping raise the bar for engineering craft across the team
Technical experise:
You don’t need to tick every box, but strong experience in most of the following is expected:
TypeScript (modern frontend and/or backend)
Python
AWS (production experience)
Postgres
Infrastructure as Code
Experience working in complex domains, regulated environments, or AI-driven products is a plus, but not essential.
This role is likely a great fit if you:
Enjoy working across the stack and owning problems end-to-end
Care deeply about code quality, design, and long-term maintainability
Like moving quickly, with autonomy and responsibility
Want to build something that genuinely changes how an entire industry works
Are comfortable making decisions with imperfect information
This is a chance to work on genuinely novel problems at the intersection of AI, law, and product in a high-trust, low-bureaucracy engineering culture.