Bloom is the app that builds mobile apps. We're unlocking a creator economy for software.

About Bloom

Bloom is a YC X25 startup building the first AI app builder that lets anyone build full-stack native apps directly from their phone, publish them to the App Store, and even airdrop apps to friends. We raised $3.4M from YC and the best angels from Expo, Convex, Hugging Face and more.
Our mission is to unlock the creator economy for software — making app development as easy as talking to your phone.

We’re a small, ambitious team in Zurich, working at the intersection of AI, code generation, design systems, and developer tooling.
You’ll be joining us at one of the most exciting moments in our journey — right after product-market fit is taking shape and with a ton of open technical problems to solve.

🧠 What You’ll Work On

You’ll work on real problems that sit at the intersection of AI, code generation, and mobile creation. Depending on your background and interests, you could:

Build and improve AI systems that can design, code, and ship complete mobile apps.
Develop and scale backend infrastructure that powers thousands of app builds every week.
Create beautiful, intuitive tools that make complex software creation feel effortless.
Build internal systems, dashboards, and agents that help us move faster as a team.
Explore new approaches to app deployment, testing, and instant sharing.

You’ll ship code that thousands of builders will use every week — and see your work go live in production within days.

🌱 About You

Core Traits

You love to build — weekends, hackathons, side projects.
You have high agency and curiosity; you move fast and learn faster.
You care about the experience of people trying to build apps for the first time.
You’re fluent in TypeScript and comfortable across the stack.

Bonus Points

Experience with React Native / Expo / Swift / Kotlin / Convex / AI SDK
Interest in RAG, fine-tuning, or evals
You’ve built something cool — even better if you’ve tried Bloom.

🧩 Example Open Problems

How do we build the world’s most reliable AI coding agent?
How can we imbue design taste into generative systems?
How do we make AI-generated apps fast, secure, and App Store-ready?
How can users share apps like content — instantly, with friends or coworkers?

🚀 Why intern at Bloom

Build with a YC-backed founding team shipping daily from Zurich.
Work on technology that’s changing how humans create software forever.
Mentorship from the most talented engineers across YC and ETH networks.
Potential to transition into a full-time role upon graduation.
🌍 Location

Bloom HQ is in Zurich, one of Europe’s most exciting tech hubs — home to ETH, a vibrant AI startup scene, and surrounded by nature, mountains and lakes. Spend your week building awesome things for thousands of users, and spend weekends outdoors or exploring Europe!

How to apply

Apply here through our YC job description. Tell us why this role speaks to you, in whichever format you feel more comfortable with.
Share something you’ve built, shipped, or led. No need to be humble about things you are proud of.
Link to your GitHub, portfolio, or anything you’ve built.
Link to your socials (X, LinkedIn, website, whatever shows off your vibe).

Interview process

Talk to David (CEO)
Talk to Sirian (CPO)
Take-home challenge

We let users create full-stack apps by speaking into their phone. We handle codegen, version control, deployment and sharing of the apps through App Clips.