Staff Software Engineer

Location: London

Employment Type: Full time

Location Type: Hybrid

Department: Technology

About the role

We’re looking for a high‑calibre Staff Software Engineer to help shape how we build and scale our products at Definely. We’re looking for someone who is highly product‑minded, intellectually curious, and motivated by solving meaningful user problems. In this role, you’ll operate across the stack, shaping both the user experience and the underlying systems, while helping define how we design, build, and scale our platform. You’ll work closely with product, design, and engineering leadership to shape both what we build and how we build it. As a Staff Engineer, you’ll drive technical and product decisions, raise the bar for quality, and play a key role in evolving our architecture as we scale.

What you’ll do:

• Lead the development of product features end-to‑end, from problem shaping with product and design through to backend implementation, frontend delivery, and iteration.
• Design and build scalable, reliable systems that power AI‑driven features and workflows.
• Translate complex AI capabilities into intuitive, performant, and trustworthy product experiences.
• Work across the stack using TypeScript and Python, contributing to both user‑facing applications and backend systems.
• Drive improvements in performance, reliability, and overall product quality across the stack.
• Contribute to technical strategy and architectural decisions across the engineering team.
• Collaborate closely with design to deliver high‑quality user experiences, while ensuring strong underlying system design.
• Raise the bar for engineering standards, including code quality, testing, and observability.
• Mentor and support other engineers, helping to elevate technical capability across the team.

What you’ll bring:

• Significant experience building and scaling complex, user‑facing products across the stack.
• Strong experience with modern frontend development (React, TypeScript) and solid backend experience (e.g. Python or similar).
• Ability to design and reason about distributed systems, APIs, and data flows.
• Strong product mindset, you think in terms of user problems and outcomes, not just implementation.
• Experience working closely with product and design to shape solutions, not just deliver them.
• Ability to take ownership of ambiguous problems and drive them through to impact.
• Experience contributing to or leading architectural decisions across systems.
• Strong communication skills and ability to influence across teams.

We'll be lucky if you:

• Have led or significantly shaped architecture in a scaling product.
• Have experience building AI‑powered or data‑heavy user experiences.
• Enjoy working in product‑driven, fast‑paced environments.
• Care deeply about usability, performance, and craft in development.
• Have experience mentoring or acting as a technical leader across teams.

What we can offer you:

• Competitive salary & annual bonus based on performance.
• Equity in Definely.
• Quarterly team socials + holiday parties.
• Hybrid working + 1 month “work from anywhere”.
• 25 days holiday + bank holidays.
• Take your birthday off.
• £750 annual learning & development budget.
• Private healthcare (incl. dental & optical).
• Enhanced parental leave + Workplace Nursery salary sacrifice scheme.
• Additional perks: Cycle to Work, Top‑quality equipment.

About Definely

At Definely, we’re building the Review layer for legal work in the age of AI. As AI transforms how contracts are drafted, the challenge is no longer just generation, it’s verification. Lawyers remain accountable for what goes out the door, but the volume and complexity of AI‑generated work is pushing traditional review to its limits. Definely gives lawyers a structured way to understand and verify complex agreements, modelling contracts as systems of definitions, cross‑references, and dependencies, surfacing hidden risks and making review more rigorous and defensible. Trusted by leading law firms and global enterprises, including A&O Shearman, Slaughter and May, BP, and Barclays, we integrate directly into the tools lawyers already use. We recently raised our Series B and are backed by Microsoft, Google, and Octopus Ventures. This is a rare opportunity to shape a new category at the moment it becomes essential.

Data Privacy Notice

By submitting your application, you agree that DEFEYENE LEGAL SOLUTIONS LIMITED ('Definely') may collect, process, and store your personal data as part of our recruitment process. We will use the information you provide to assess your qualifications for the role you are applying for and to communicate with you regarding your application. Your personal data will be stored for up to 12 months, after which it will be securely deleted unless we have another lawful basis to retain it. You have the right to access, correct, or request the deletion of your data at any time. For more details on how we handle your personal data and your rights, please send us an email to people@definely.com and we will send you our privacy policy. If you have any concerns about how your data is being processed, please do not hesitate to contact us.