Senior Backend Engineer, Portfolio team (Python)

About InvestEngineWe're a London-based fintech on a mission to make ETF investing simple and accessible. Over 150,000 clients have trusted us with over £3.5 billion in assets — and we're just getting started.We've been featured by MoneyWeek, Finder and Forbes, and we're growing fast with big ambitions.About the RoleWe're looking for a Senior Backend Engineer to join our Portfolio Team and help build the core investment products our clients use every day.The team owns portfolio creation, Managed Portfolios and related portfolio operations. This is product development work: you'll turn product ideas into reliable, well-built backend features that directly shape how clients invest.You'll write high-quality code, raise the bar through thoughtful code reviews, contribute to architecture and lead projects from requirements to production. You'll work closely with Product, frontend, QA, mobile and design in a small, autonomous team with a clear roadmap.What You'll DoDesign, develop and maintain backend services in Python 3.11 using Django / DRFBuild features for portfolio creation, Managed Portfolios and portfolio operationsLead roadmap projects end-to-end: clarify requirements with Product, propose the technical design, break down the work and ship itDesign and build RESTful APIs used by our web and mobile appsGive constructive, high-quality code reviews and help raise the team's engineering standardsTake part in architecture discussions and contribute to technical decisionsWork with MySQL and RedisIdentify and reduce technical debtCollaborate closely with Product, frontend, QA, mobile and designContribute to the evolution of our architecture and engineering practicesWhat We're Looking For5+ years of experience in backend developmentStrong Python skills and solid software engineering fundamentalsA good understanding of software architecture and service designSolid experience with relational databases and REST API designA track record of writing clean, maintainable, well-tested codeExperience leading projects or features from idea to productionThe ability to pick up new codebases and technologies quicklyStrong ownership, organisation and a collaborative working styleFamiliarity with Git, CI/CD practices and modern engineering workflowsGood written and spoken EnglishNice to HaveExperience with Django or Django REST Framework (not required, since strong fundamentals matter more than an exact framework match)Experience in fintech, investing, wealth management or another regulated industryFamiliarity with AWS and DockerExperience with RabbitMQ, Kafka or other message brokersExperience using AI-assisted development tools in your daily workContributions to open source or personal side projectsHow We WorkWe're a lean, collaborative team where engineers have real influence on architecture, technical decisions and engineering culture.The Portfolio Team is strong and autonomous. We work in two-week sprints with Product involved throughout, and we have a clear 3–6 month roadmap. You'll have the freedom to make technical decisions and own meaningful parts of the product without micromanagement or unnecessary bureaucracy.What We OfferImpact from day one: work on core investment products used by more than 150,000 clientsOwnership: lead projects and become the go-to backend owner for key areas of the Portfolio domainTechnical growth: influence architecture and technical decisionsModern tech stack: Python 3.11, Django, MySQL, Redis, AWS, GitHub, TeamCityRemote-first and flexible: work from anywhere, at your own paceUnlimited vacation: take time off when you need it, with no fixed limitsSupportive team: thoughtful, skilled colleagues who care about quality and resultsHiring ProcessHR interviewTechnical interview with the Backend teamConversation with the Portfolio team leadershipGamified cognitive assessment to understand how you think and solve problems