Senior Full Stack Software Engineer | AI Startup

Senior Full Stack Software Engineer | AI Startup £80,000–£100,000 + Equity London | Hybrid (2–3 days per week with flexibility) Our client is hiring a Senior Software Engineer to help build the software platform behind a next-generation AI authentication product that's changing how people securely interact with technology. The AI doesn't rely on passwords, fingerprints or facial recognition. Instead, it learns how people naturally interact with their devices to create seamless, continuous authentication. You'll build the production systems that make this possible. What makes this different? You'll solve the engineering challenges that turn cutting-edge AI into a product customers trust: Building scalable backend servicesDesigning APIs that support AI-powered featuresDeveloping cloud-native systems on AWSRunning highly available Kubernetes workloadsBuilding intuitive web applicationsMaking AI reliable, observable and production-ready You'll work directly alongside AI Engineers, influencing architecture and making technical decisions from day one. Why engineers join startups like this Large companies have specialists for everything. Here, you'll own problems end to end. One week you might be designing backend services. The next you'll improve frontend experiences. The week after you'll be helping shape infrastructure or influencing product direction. If you enjoy variety, ownership and solving difficult engineering problems, you'll feel at home. You'll enjoy this role if you like: Building products from the ground upWorking across the full stackMaking architectural decisionsShipping software quicklySeeing the direct impact of your workCollaborating with AI EngineersSolving real engineering problems rather than maintaining legacy systems Technology Stack TypeScriptNode.jsReactAWSKubernetesDockerREST APIsCI/CD We're far more interested in great engineers than someone who has used every tool on this list. We'd love to hear from you if you have experience with: Building or supporting software platforms that power AI or Machine Learning products in productionCommercial software engineering (5+ years)TypeScript and Node.jsCloud-native applicationsAWS and/or KubernetesBuilding production softwareDesigning scalable APIsModern software architecture What you'll get £80,000–£100,000 base salaryHybrid working with flexibilityA genuinely small engineering team where your voice mattersThe opportunity to shape architecture, engineering practices and product directionThe chance to build software powering real-world AIIf you're looking for more ownership, greater technical influence and the opportunity to help build something from an early stage, we'd love to hear from you.