Staff Engineer, Software Engineer

Join to apply for the Staff React Engineer role at Definely
.

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

We are looking for a Staff Engineer to guide two mid‑senior React developers, providing architectural guidance and technical direction. You will shape product direction and product triad.

• Team Leadership & Mentorship – Lead and inspire a team of React developers, foster collaboration, mentor, promote best practices, maintain high code quality.
• Technical Excellence – Architect and develop sophisticated React applications integrated with Microsoft Word, M365, Word Online using Office.js, write clean, efficient code, drive scalable solutions, think outside of Office
  
  JS limitations.
• Product Development – Collaborate with cross‑functional teams to deliver innovative features, create exceptional UIs prioritizing UX and accessibility, optimize performance.
• Quality & Documentation – Establish testing, debugging processes, maintain documentation, implement security best practices.
• Problem Solving & Innovation – Troubleshoot complex challenges, contribute to architectural discussions, improve developer productivity via tooling and AI.

• Minimum 5 years of product‑focused React development experience.
• Proven leadership in software development teams.
• Expert proficiency in React, Type Script, JavaScript, HTML, CSS.
• Strong experience with Microsoft Office integration (Office.js, Word add‑ins).
• Experience with agentic coding assistants such as Claude Code.
• Excellent English communication skills.
• Demonstrated ability to work autonomously with clear direction to others.
• Extensive experience in remote environments.
• Passion for knowledge sharing and team growth.
• Optimization skills for React (memoization, code splitting, etc.).
• Strong grasp of Git, CI/CD pipelines.
• Excellent problem‑solving, collaboration, and communication 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.
• Experience with in‑browser text editors and performance optimization.
• Experience in product‑focused or startup environments.
• Exposure to AI‑powered developer tools and workflows.

• Competitive salary & annual bonus
• Equity in Definely
• Quarterly team socials & annual company offsite
• Hybrid working (Tues & Thurs in‑office) + 1 month “work from anywhere”
• 25 days holiday + bank holidays
• £750 annual learning & development budget
• Private healthcare (incl. dental & optical)
• Enhanced parental leave
• Additional perks:
  Cycle to Work, Workplace Nursery salary sacrifice scheme, top‑quality equipment

At Definely, we simplify how legal professionals access and understand complex information in legal documents. Trusted by a global community, our Legal Tech solutions integrate seamlessly into lawyers’ daily workflows, making drafting, reviewing, and navigating contracts faster and safer.

Joining Definely means being part of a forward‑thinking, collaborative team that prioritises innovation and people. We support growth and success for our team and customers.

Recognised in the top 25 of Deloitte’s prestigious UK Technology Fast
50 in 2023 and backed by Microsoft, Google, and Octopus Ventures, we are trusted by leading law firms and in‑house legal teams worldwide.

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  and we will send our privacy policy. If you have any concerns about how your data is being processed, please do not hesitate to contact us.