Senior Full Stack Developer React/FastAPI/Django (Frontend-Affinity) (m/f/d)

mika is revolutionizing financial management for small businesses with an AI-powered platform that combines automated accounting, proactive insights, and conversational AI. We're on a mission to make expert financial navigation and compliance accessible to every small business owner – dramatically reducing costs and bureaucratic burden. We're a small, senior team shipping fast, and every line of code we ship matters. Our stack: FastAPI & Django backend, React frontend (Material UI, react-query), PostgreSQL, AWS. We build agentic AI systems that do real accounting work. ## Tasks We need a Senior Full-Stack Developer who leans frontend – someone who makes our product _look and feel_ as good as it works under the hood. You'll own features end-to-end. That means you think through the entire user flow, edge cases, error states, and architecture _before_ you start building. You work with high autonomy and take real ownership – we trust you to make good decisions and deliver clean solutions. Concretely, you'll: * Drive **frontend improvements** – not just fixing bugs but proactively elevating UX and visual quality on a regular cadence * Build and own **complex full-stack features** in our accounting platform * Use **Claude Code, Cursor, or similar AI engineering tools** as your primary development workflow – we are a senior team where everyone writes high-quality code at a high pace, and this is only possible through the use of the latest coding tools. You'll get access to all the subscriptions you need to work efficiently * Adapt and extend our Python/FastAPI & Django backend where needed (CRUD-level changes and beyond) * Contribute to **code quality and architecture decisions** in a small senior team ## Requirements * Professional experience in software development with a proven track record of owning and delivering complex projects. * Expertise in React to build high-quality, accessible, and production-ready user interfaces. * A sharp eye for design that ensures layouts and components are implemented with pixel-perfect accuracy. * Hands-on skill with AI-assisted engineering using tools like Cursor, Claude Code, Codex, or GitHub Copilot. You have already built real things with those tools. * The ability to work across the stack by independently navigating and extending a Python/FastAPI backend. * A systems-thinking mindset to map out full features, edge cases, and failure modes before writing any code. * Fluency in English, while any knowledge of German is a welcome bonus. Nice to have: * Background in agentic AI systems or LLM-powered products. * Familiarity with B2B fintech, PostgreSQL, or German accounting standards like DATEV. ## Benefits * A small team of strong, senior engineers who respect each other's time. * Real autonomy and ownership from day one. * Work that's genuinely hard and interesting – German tax law + AI agents is not a solved problem. * Competitive salary and a product that's actually used by real customers daily. * Almost no meetings – on average 95% focus time per day. * 100% Remote option, option to work abroad and no minimum required office attendence. * Fully flexible working hours apart from Daily Standup. * Berlin location preferred but remote possible. _We welcome applications from people of all backgrounds, genders, and identities._