Staff Software Engineer

Definely

Staff Software Engineer at Definely shaping product development and scaling AI-driven solutions. Leading development across the stack while collaborating with product, design, and engineering teams.

Posted 5/11/2026full-timeLondon • 🇬🇧 United KingdomLeadWebsite

Tech Stack

Tools & technologies

Distributed SystemsPythonReactTypeScript

About the role

Key responsibilities & impact

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

Requirements

What you’ll need

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

Benefits

Comp & perks

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

ATS Keywords

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Applicant Tracking System Keywords

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Hard Skills & Tools

TypeScriptPythonReactdistributed systemsAPIsdata flowsscalable systemsAI-driven featurescode qualitytesting

Soft Skills

product mindsetcommunication skillsinfluenceownershipproblem-solvingmentoringcollaborationtechnical capabilitydesign reasoningiteration