Senior Fullstack Engineer (React/Next.js) - Lead Engineer Role (m/f/d)

Hello, we are PHONT, a young startup on a mission to bring subtitles to life. We use AI to capture tone, emotion and tempo of speech, and turn those cues into animated subtitles – so every viewer can feel the story, even with the sound off. Backed by recent funding, we’re building the next generation of subtitle technology at the intersection of media and tech.

We’re looking for a Senior Fullstack Engineer with a front-end focus to join as one of our first team members. You will own our front-end codebase and the glue to our audio-analysis backend. This is a high-impact lead engineer position – ideal for someone who loves to mix cutting-edge frontend development with backend and infra.

• Lead Frontend Development: Migrate our prototype frontends into a production-grade Next.js 14 app. Design the architecture for scale and maintainability as we grow.
• Build Real-Time Features: Develop a type-safe API (tRPC/REST/GraphQL) to interface with our Python audio analysis engine, optimizing for low-latency streaming of data. Make sure subtitles and emotions appear on screen in real time.
• Creative Prototyping: Work with our design/ML team to build emotion-driven subtitle animations in the browser. Experiment quickly with libraries like Framer Motion or WebGL, and turn successful experiments into core features.
• DevOps & Quality: Set up CI/CD pipelines, automated testing, and infrastructure-as-code. Ensure we can release features confidently and continuously.
• Tech Leadership: As a lead engineer, establish coding standards and best practices. Mentor future hires or junior contributors. You’ll have significant influence on technical decisions and the product roadmap.

• Frontend Expertise: 3+ years building modern web applications with React.js, Next.js and TypeScript. You’ve built responsive, performant UIs and have an eye for good design.
• Full-Stack Know-How: Comfortable writing backend logic for APIs and working with databases. Fluent in HTTP/WebSocket fundamentals and crafting efficient data contracts between client and server.
• Creative Coding Mindset: Passion for visual polish – maybe you’ve dabbled in creative coding (Canvas, WebGL, SVG animations) or have a portfolio of visually impressive projects. You care about pixels and performance.
• Ownership & Drive: You love taking projects from 0→1. Experience migrating prototypes to production – you favor iterative improvement over big rewrites. Startup mindset (rapid testing, adaptability, “done is better than perfect”) and the strive to ship your first feature to production by end of the first week.
• Quality Focus: Write clean, maintainable code. You have used or set up CI/testing pipelines and appreciate the value of automated tests.
• Team Player: Excellent communicator, able to work closely with non-technical colleagues. You share knowledge, seek feedback, and thrive in a collaborative environment.
• Cloud deployment know-how (AWS, Azure) and infrastructure scaling.

Nice to Have

• Experience with audio/video processing (e.g. FFmpeg) or media streaming.
• Familiarity with Framer Motion, GSAP or other animation libraries.
• Contributions to design systems or creative tech libraries (e.g. Three.js, p5.js).
• German language skills (not required; our working language is English)

• Impact & Ownership: Join a core team of founders and shape a product from the ground up. Your decisions will define our tech stack and user experience.
• Competitive Salary + Equity: We offer a market-rate salary (commensurate with experience) and VSOP stock options (participate in our success). We’ll discuss a range openly to ensure we’re aligned.
• Creative Culture: We blend engineering with art. If you get excited by creative coding, generative art, or pushing the boundaries of UI, you’ll feel at home. We value design and pixel-perfection as much as robust code.
• Growth Opportunities: As an early employee, you can grow into a Lead Engineer role. You’ll mentor others and define our engineering culture.
• Flexible Work: Hybrid-friendly – work remotely or join us in our Frankfurt office. Flexible hours as long as the work gets done.
• Equipment & Learning: New MacBook Pro or Windows laptop of your choice, plus budget for conferences, courses, or creative projects in the realm of human-computer interaction.

Our Mission is to Make Subtitles Come Alive. If the idea of turning audio sentiment into living design excites you, we want to hear from you!

How we hire

1. Jump in an intro call with the team.
2. Complete the take-home exercise
3. Show us how you approach problems during two technical interviews
4. Join us for trial work lasting 2 days. We'll see how you tick and you get to meet the team and explore whether joining PHONT feels right for you.

How to Apply

No formal cover letter needed:

• Your CV or LinkedIn
• Links to projects or a portfolio/GitHub – especially any creative coding or full-stack projects you’re proud of,
• (Optional) A brief note on the boldest tech challenge or prototype you’ve built/migrated, and what you learned from it.

We review every application personally.