Job Description

Bloom is a Y-Combinator backed startup building the future of app development. We raised $3.4M from leading U.S. investors, and are now establishing our Swiss subsidiary in Zurich, to grow our engineering team.

We are seeking a

Founding Convex Engineer

who will lay the foundation of our technical infrastructure and, depending on fit, grow into our CTO role. This role requires a

rare combination of advanced Convex, Expo, and React expertise

, with demonstrable experience in building and scaling full-stack applications in production.

Core requirements:

1. Convex expertise:

Minimum 2 years hands-on experience with Convex in production. Deep knowledge of advanced Convex modules: Real-time query subscriptions, row-level security and access control enforcement, schema evolution and database migrations, query optimization and indexing strategies. Proven ability to design and maintain complex Convex schemas at scale.

2. Expo expertise:

Minimum 2 years building and shipping production apps with Expo.
Experience with:

Expo Application Services (EAS) builds. Over-the-air (OTA) updates. Deep linking and navigation. Push notification pipelines. At least one published app in the App Store or Google Play built with Expo.

3. React/TypeScript expertise:

Demonstrated mastery of React concurrent features (Suspense, concurrent rendering). Advanced state management experience (React Query, Recoil, or equivalent). Deep knowledge of TypeScript type-safety in large-scale applications. Contributions to open-source React/TypeScript projects (with GitHub proof).

4. AI integration skills:

Practical experience with LLM-driven developer tools, including coding agents, retrieval-augmented generation (RAG), fine-tuning, and evals. Ability to design developer workflows where AI generates schemas, APIs, or UI components automatically.

5. Portfolio proof:

GitHub profile with at least two large-scale projects demonstrating Convex + Expo integration. Evidence of production deployments (live apps, OSS contributions, or technical talks/blogs).

6. Startup mindset:

Prior experience at a YC startup or as a founder. Demonstrated ability to operate with high agency in fast-paced environments. High levels of endurance.

Bonus Points

Strong background in Swift/Kotlin/React Native. Experience architecting multi-tenant mobile app backends. Contributions to Convex or Expo open-source communities. Proven record of mentoring engineers or leading small teams. Graduate of top 10 engineering schools worldwide. Hackathon winner.

What You'll Work On

Designing core Convex schemas and APIs to power an AI agent capable of generating production-grade mobile apps. Solving difficult technical challenges including schema migrations, authentication/authorization, payments, and real-time reliability across thousands of subscriptions. Building an Expo client that demonstrates seamless integration with Convex and showcases AI-assisted app creation. Developing tools that give creators insight, control, and scalability for their apps. Establishing the long-term technical architecture and engineering culture of Bloom.

Benefits

Fast growth curve Top quartile compensation Options Beautiful office 1 min from ETH Zurich Best in-class Apple hardware

How to Apply

Provide GitHub links proving Convex, Expo, and React expertise. Share evidence of published Expo apps in App Store/Google Play. Describe your experience with AI-powered developer tools. Include your thoughts on solving Bloom's open problems.

Interview Process

Vibe check with COO Advanced Convex take-home task Call with both Co-Founders
Job Type: 100%

Pay: CHF120'000.00 - CHF190'000.00 per year

Benefits:

Company pension
Ability to commute/relocate:

8001 Zurich, ZH: Reliably commute or willing to relocate with an employer-provided relocation package (Preferred)
Experience:

Convex: 2 years (Required)
Language:

English (Required)
Work Location: In person