Engineering Lead; React

Location

London

Full time

Hybrid

Technology

Following our recent $30M Series B funding, we're expanding the team to accelerate development of our legal technology products that integrate with Microsoft products through Office.js.

We're looking for a React Team Lead to guide 2 mid-senior React developers who will look to you for architectural guidance and technical direction.

As the technical side of the product Triad, your technical decisions will directly shape product direction.

• Lead and inspire a team of React developers, fostering a collaborative environment where knowledge sharing is valued and encouraged

• Mentor team members, helping them grow their skills and advance their careers

• Promote best practices and maintain high code quality standards across the team

• Architect and develop sophisticated React applications that integrate with Microsoft Word, M365, Word Online, etc. using Office.js

• Write clean, efficient, and maintainable code

• Drive technical decisions and ensure scalable, performant solutions

• Think outside of the box to workaround any Office
  
  JS limitations.

• Collaborate closely with cross-functional teams to bring innovative features to life

• Create exceptional user interfaces that prioritize user experience and accessibility

• Continuously optimize application performance and responsiveness

• Establish robust testing and debugging processes to ensure high-quality, reliable software

• Maintain comprehensive documentation for code, APIs, and system architecture

• Implement security best practices to protect user data and ensure system integrity

• Troubleshoot and resolve complex technical challenges.

• Contribute to architectural discussions and drive the evolution of our tech stack.

• Improve developer productivity through tooling, automation, and AI-assisted coding.

• Minimum 5 years of hands‑on, product‑focused experience with React development

• Proven leadership experience in software development teams

• Expert‑level proficiency in React, Type Script, JavaScript, HTML, CSS, and modern web technologies

• Strong experience with Microsoft Office integration, particularly Office.js and Word add‑ins

• Experience with agentic coding assistants such as Claude Code

• Excellent English communication skills, both written and verbal

• Demonstrated ability to work autonomously while providing clear direction to others

• Extensive experience working effectively in remote environments

• Passion for knowledge sharing and helping team members grow

• Know how to optimise React apps (prevent useless re‑rendering, memoisation, code splitting etc)

• Strong grasp of Git, version control best practices, and CI/CD pipelines.

• Excellent problem‑solving, communication, and collaboration skills.

• Ability to work effectively in a fast‑paced, agile environment.

• Knowledge of Microsoft Office Add‑in guidelines and Office Store submission processes

• Background in Legal Tech or professional services software

• Previous experience working with in‑browser text editors, specially if you were part of optimisation efforts to make the experience snappier.

• Experience in product‑focused or startup environments.

• Exposure to other AI‑powered developer tools and workflows.

At Definely, we’re on a mission to simplify the way legal professionals access and understand complex information in legal documents. Trusted by a global community of customers, our Legal Tech solutions integrate seamlessly into lawyers' daily workflows, making it easier to draft, review and navigate even the most complex contracts.

Our products provide instant access to essential information, enabling legal teams to review clauses and provisions in context, reduce risk and work more efficiently – all without disrupting their flow. At Definely, we’re dedicated to solving real challenges faced by legal professionals.

Joining Definely means becoming part of a forward‑thinking, collaborative team that prioritises innovation and people. We create a supportive environment driven by a shared commitment to connection,…