Lead Engineer

Definely Ltd.
London
About the role

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 Staff Engineer to guide two 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.

What you'll do:

Team Leadership & Mentorship
  • 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
Technical Excellence
  • 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 OfficeJS limitations.
Product Development
  • 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
Quality & Documentation
  • 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
Problem Solving & Innovation
  • 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.
What you'll bring:
  • Minimum 5 years of hands-on, product-focused experience with React development
  • Proven leadership experience in software development teams
  • Expert-level proficiency in React, TypeScript, 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 optimize React apps (prevent useless re-rendering, memoization, 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.
We'll be lucky if you have:
  • Knowledge of Microsoft Office Add-in guidelines and Office Store submission processes
  • Background in LegalTech or professional services software
  • Previous experience working with in-browser text editors, specially if you were part of optimization efforts to make the experience snappier.
  • Experience in product-focused or startup environments.
  • Exposure to other AI-powered developer tools and workflows.
What we offer:
  • Competitive Salary
  • Annual bonus: Recognising and rewarding the results you deliver, aligned with overall company success.
  • Equity: We want everyone to share in Definely's success, so you'll receive stock options as part of your package.
  • Hybrid flexibility: We come in on Tuesdays and Thursdays, with the flexibility to work remotely the rest of the week.
  • Learning and Development: Annual budget of £750 to spend on your learning, growth, and development
  • Time Off : Enjoy 25 days of holiday per year, plus UK bank holidays, to recharge and unwind.
  • Private Healthcare : Access to Vitality healthcare, including dental and optical.
  • Enhanced Parental Leave: We support working parents with generous parental leave policies that go far beyond statutory requirements
  • Workplace Nursery Scheme : Saving working parents lots of money through our salary sacrifice scheme!
  • Cycle to Work Scheme : Save on a new bike and accessories while promoting a healthier, more sustainable commute.
About Definely

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 LegalTech 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, growth and success.

Recognised in the top 25 of Deloitte's prestigious UK Technology Fast50 in 2023 and backed by Microsoft, Google and Octopus Ventures, we're trusted by leading law firms and in-house legal teams, including A&O Shearman, Dentons, Deloitte, and Barclays, to streamline their workflows and mitigate risks.

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 [email protected] and we will send your our privacy policy.

If you have any concerns about how your data is being processed, please do not hesitate to contact us.
Posted 2025-10-15

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