Senior & Staff Product Engineer - Python AI

x4 Senior & Staff Product Engineers - Python | AI-Native, Cybersecurity Start-up | £90-140K base with equity | London, 3 days I'm partnering with an ambitious, early-stage technology company operating at the intersection of AI and cybersecurity, tackling some of the most complex challenges in an industry undergoing significant transformation. They're building sophisticated, AI-powered technology to help organisations navigate an increasingly complex digital landscape, with a particular focus on automation, scalability and solving difficult technical problems. They're now looking to hire multiple exceptional Senior & Staff Product Engineers to join their growing engineering team in London. They're looking for engineers who combine deep Python expertise with exceptional product thinking, genuine end-to-end ownership and an enthusiasm for AI-native software development. x4 Senior & Staff Product Engineers - Python | AI-Native, Cybersecurity Start-up | £90-140K base with equity | London, 3 days This is genuine product engineering. You'll work on technically complex products, taking ambiguous problems, understanding what users actually need and owning solutions from idea through to production. You'll have significant autonomy over what gets built, how it's designed and the technical decisions behind it, working alongside a team of highly capable engineers. They're particularly interested in engineers operating at Tech Lead or Staff Engineer level who want to remain deeply hands-on rather than move into people management. You'll also be joining an environment that embraces AI-native engineering, where AI agents are becoming an integral part of how software is designed, developed and delivered. What you'll be doing | x4 Senior & Staff Product Engineers - Python | AI-Native, Cybersecurity Start-up | £90-140K base with equity | London, 3 days Own complex product problems end-to-end, from understanding user requirements through to production.Build and scale sophisticated backend systems and APIs using Python.Design robust relational data models and work extensively with SQL.Work closely with end users, understanding their challenges and translating them into exceptional products.Embrace AI agents and AI-assisted development to accelerate engineering productivity and solve increasingly complex problems.Make pragmatic architectural decisions around scalability, performance, security and reliability.Take ownership of production systems, improving testing, observability and developer experience.Influence technical direction, engineering standards and architecture as the company scales. What they're looking for | x4 Senior & Staff Product Engineers - Python | AI-Native, Cybersecurity Start-up | £90-140K base with equity | London, 3 days They're looking for exceptional engineers who combine deep technical expertise with genuine product thinking, ownership and an enthusiasm for AI-native software development. Senior, Tech Lead or Staff-level engineering experience, with strong technical leadership skills and a desire to remain hands-on.Deep commercial experience with Python, alongside excellent backend engineering fundamentals.Strong expertise in SQL and relational data modelling, including designing and optimising complex databases.Experience designing, building and operating high-quality production software.A genuine product engineering mindset – understanding end users, challenging assumptions and focusing on outcomes rather than simply completing tickets.Already embracing AI agents and AI-assisted development in your everyday engineering workflow, going beyond basic autocomplete.Strong architectural judgment and the ability to independently tackle complex, ambiguous engineering problems.Comfortable working across the stack when required, taking ownership beyond your immediate technical specialism.Experience in a start-up, scale-up or similarly high-ownership engineering environment.High standards around code quality, testing, security, reliability and simplicity. Particularly interesting: Engineers with experience designing authentication, authorisation or security-critical systems, including identity management, complex permissions and access control. Previous cybersecurity experience would be advantageous, but isn't essential. They're far more interested in exceptional engineers with strong product instincts who are genuinely excited about AI and the problems they're solving. The opportunity | x4 Senior & Staff Product Engineers - Python | AI-Native, Cybersecurity Start-up | £90-140K base with equity | London, 3 days £90,000–£140,000 base salaryMultiple Senior & Staff Product Engineering opportunitiesEarly-stage AI-native technology company operating in cybersecurityGenuine technical leadership without people managementAI-native engineering environment, embracing agents and modern development practicesSignificant ownership over architecture, technology and product directionLondon – Hybrid, 3 days per week in the office This should appeal to engineers who want to remain deeply hands-on, solve genuinely difficult technical and product problems, and have significant influence over both the technology and the products being built. You'll be joining an environment that embraces the future of software engineering, working on meaningful challenges where technical excellence, product thinking and ownership genuinely matter. If you're an exceptional Senior Python Engineer, Product Engineer, Tech Lead or Staff Engineer who loves building products, embraces AI-native development and wants genuine ownership, send over an updated CV and I'll be in touch if I think there could be a strong match. 🙂