Senior Full Stack Engineer

Full Stack Engineers: Let 250+ Companies Compete For You

Fonzi is an AI recruiting company.

No job boards. No recruiter spam. Companies request to interview you and submit salary bids upfront.

Every week, hiring managers at 250+ pre-vetted startups in NYC and San Francisco review a curated group of engineers. They're reading profiles optimized by our team to surface what matters: what you've built, how you think about systems, and whether you're the kind of engineer who ships.

Companies on Fonzi are Applied AI startups, Frontier labs, Hypergrowth startups, PE firms starting lean AI teams and more. They're backed by investors like A16z, Sequoia Capital, General Catalyst, Y Combinator and more.

How It Works

• 5-minute application
• We reach out, learn what you're building and what excites you, and optimize your profile
• Hiring managers review the cohort and request interviews with candidates they want
• Companies submit competing salary bids directly to you
• You only interview where you're genuinely interested
• Completely free. We have an iMessage agent + humans in the loop you can text anytime w/ questions or requests to help handle scheduling and coordination

Who We're Looking For

The full stack engineers who do best on Fonzi:

• Have shipped complete features end-to-end: data model, API and a UI real users depend on
• Are strong in a modern stack (TypeScript, React, Node or Python, Postgres) and pick up new ones fast
• Have built product features on top of LLMs, or are actively building with them
• Care about the product and the user, not just closing tickets
• Thrive in startup environments where the problem is ambiguous and the team is small
• Have 2-8 years of experience, ideally with experience at at least one high-growth company

What You'll Build

The companies on Fonzi are working on:

• AI-native web apps where the LLM experience is the core product
• Customer-facing workflows and dashboards across healthcare, fintech, legal and logistics
• Agent-driven and real-time interfaces that turn complex AI output into something usable
• APIs, integrations and data models that scale from MVP to enterprise
• Products serving real customers today, where one engineer owns a feature from schema to screen

Compensation

• $160,000 to $275,000+ base salary depending on experience and role. Many positions include meaningful equity at pre-seed through Series B stage companies.

The Interview Process (Typical)

• Screening conversation looking for communication skills, cultural fit and product sense
• Technical deep-dive on how you'd build a feature end-to-end, from data model to UI
• Coding or pairing session building a realistic full stack feature

If you love owning features from database to UI and you're building with AI every day, we want to hear from you.