Java full stack developer Jobs in Langen

Stellenbeschreibung

Intro Hello, we’re PHONT , a startup from Frankfurt on a mission to make subtitles feel as rich as spoken dialogue. Our AI-driven platform captures tone, emotion, and tempo, then paints those cues straight onto the screen—so every viewer, everywhere, can sense the full story while watching subtitled content. We’re now looking for a full-stack engineer to own the UI layer and the glue that binds it to our audio-analysis engine. You’ll spearhead code-migration from experimental prototypes to a robust production stack, shaping the product architecture as decisively as the visuals themselves. Tasks Lead the migration of our existing front-end prototypes into a production-grade Next.js 14 codebase. Design a type-safe API layer (tRPC / GraphQL or REST) that talks fluently to our Python audio-analysis backend—optimizing for low-latency, real-time data streaming. Collaborate with design and machine-learning teams to prototype emotion-driven animations in the browser, shipping quick experiments and folding lessons back into the core code. Establish CI / CD pipelines, automated testing (Playwright + Vitest), and infrastructure-as-code practices. Mentor junior contributors in coding standards that balance creative freedom with software development . Optionally : Implement responsive, accessible, and emotionally-aware subtitle components using React and motion libraries (Framer Motion or GSAP). Requirements Hands-on experience shipping full stack React / Next.js apps in a startup or similar setting—comfortable with ambiguity, rapid iteration, and wearing many hats. Demonstrated success migrating prototypes into coherent component libraries, with an eye for progressive refactor over rewrites. Solid command of TypeScript, modern state-management paradigms (Zustand, React Query, or Redux Toolkit), and CSS-in-JS or utility-first frameworks. Fluent in HTTP fundamentals, WebSockets, and crafting secure, performant data contracts between front- and back-end. A portfolio that shows both coding skills and visual flair —we want to see side-projects, generative art, or anything that proves you care about pixels. Startup mindset : you default to action, validate assumptions with lightweight experiments, and know when "good enough today” beats "perfect next month.” Nice-to-haves : Familiarity with audio / video pipelines, Web Audio API, or FFmpeg. Experience with cloud platforms (AWS, Azure) for building scalable, high-performance web apps Contributions to open-source design-systems or creative-coding libraries (Three.js, p5.js). Experience with media encoding, MediaRecorder, and WebGL. 2+ years of full stack engineering experience. Benefits Ownership from day one with significant influence on architecture, design language, and product roadmap. A culture that prizes both build / design quality and rapid MVP testing. Flexible hours and remote-friendly workflow, with an office space in Frankfurt. Next to a base salary the option for virtual shares to participate directly of success. (Time-)Budget for conferences, hardware, and experimental side-projects in the realm of human–computer expression and creativeness. Closing Our goal at PHONT is To Bring Subtitles to Life . If you thrill at the idea of turning audio sentiment into living, breathing UI - we can’t wait to see what you’ll build. Write Send us your form-less application, with projects that you built in the past, your GitHub handle, and optionally a breakdown of the boldest migration, creative-coding, or full stack application you’ve pulled off. Let’s create the next generation of subtitles together!