About the Role
A Y Combinator–backed EdTech startup in San Francisco is hiring a Founding Full-Stack Engineer to join its founding team. The company is building an immersive, short-form video language-learning platform — backed by science and already trusted by hundreds of thousands of learners — that helps people achieve real conversational fluency.
This is an in-person, early-stage role with meaningful equity. You'll work side-by-side with the founders every day, own large portions of the codebase, and have a direct hand in shaping product direction, engineering culture, and architecture from the ground up. The stack spans mobile, web, backend, infrastructure, and AI.
What You'll Do
- Work in-person with the founding team daily in San Francisco.
- Own broad parts of the codebase across mobile, web, backend, infrastructure, and AI.
- Ship complete end-to-end product features — from backend logic through UI to production deployment.
- Build high-performance mobile experiences in React Native.
- Implement and maintain video streaming and HLS pipelines.
- Develop AI-driven learning experiences using LLMs and audio/video models.
- Build and maintain backend services in Go.
- Design data models, schemas, and performance optimizations in PostgreSQL.
- Improve developer tooling, CI/CD pipelines, and observability.
- Influence foundational architecture, engineering culture, product direction, and UX.
- Move fast without sacrificing quality, craftsmanship, or reliability.
What We're Looking For
Dealbreakers (must-haves):
- 3+ years of professional software engineering experience delivering end-to-end features across mobile, web, and backend systems.
- Experience building backend services in Go (Golang) with PostgreSQL, including data modeling and performance optimization.
- Proven experience delivering mobile apps using React Native (Expo) or native iOS/Android development.
Required skills:
- Strong TypeScript fundamentals and solid foundations in HTML, CSS, JavaScript, and REST APIs.
- Deep knowledge of at least two compiled languages — Go plus one of Swift, Kotlin, C++, Java, or C#.
- Writes testable code with unit, integration, and end-to-end tests (mocks, pure functions).
- Experience with at least one scripting language (Python or Ruby) for tooling and automation.
- Comfortable with Unix-based systems, Git, and terminal workflows.
- Strong debugging skills using Chrome DevTools, RN profiler, or Xcode Instruments.
- Familiarity with video streaming (HLS) and building AI/LLM-driven features.
Nice to have:
- Cloud experience (AWS, GCP, Azure, or DigitalOcean).
- CI/CD experience with GitHub Actions.
- Profiling and performance optimization experience.
- Prior startup or founder experience.
- Comfortable using AI development tools (Cursor, Copilot, GPT, Claude, etc.).
- Speaks multiple languages or is actively learning a spoken language; familiarity with immersion-first language learning is a plus.
Compensation & Benefits
- Salary: $150,000 – $200,000 USD annually
- Equity: Meaningful founding-team equity package
- Visa sponsorship: Available when needed
Location
This role is fully on-site in San Francisco, CA. Candidates must be willing and able to work in person full-time. Visa sponsorship is available.