Founding Software Engineer

About the company

Our client is a fast-growing consumer software company.

The role

Raydar is recruiting for this role on behalf of our client. Own the design and delivery of application and backend features for a widely used consumer product, working side by side with company leadership. The work centers on applied AI systems and the infrastructure behind them, in a compact, in-person environment.

What you'll do

- Build and refine the core AI agent framework, covering tool use, memory, prompting, retrieval and evaluation.

- Take features from architecture through launch and ongoing iteration across the user-facing app and backend services.

- Partner directly with the founders to shape a simple, polished user experience.

- Extend agent capabilities with sandboxed tooling and backend and database infrastructure designed to scale.

- Help deploy and tune GPU infrastructure, including fine-tuning and serving open-source language models.

- Weigh tradeoffs between speed, spend, stability, data protection and usability when making technical decisions.

- Contribute to future product initiatives as the company grows.

Requirements

What we're looking for

- Solid engineering background across the full stack or on the backend.

- Hands-on experience building an agentic system that goes beyond simple LLM SDK calls, including tool calling, memory and system prompts.

- Practical experience with open-source language models, such as serving, fine-tuning or evaluation.

- A history of building and shipping your own product, whether a startup, side project or open-source work, with measurable results such as users, revenue or adoption.

- A public code portfolio showing personal projects and recent, steady activity.

- Clear, effective communication.

- Comfort taking ownership of whatever needs attention in a lean team.

- Willingness to work an intense early-stage schedule, up to 7 days a week with 5 in the office.

Bonus points

- Founding or early engineer experience at an applied AI or consumer startup.

- Strong consumer product instincts.

- Open-source contributions.

- A long coding history that predates AI coding tools.

Benefits

Compensation and benefits

- Base salary: USD 150,000 to 250,000 per year

- Equity

Location and work model

- New York, NY, United States

- On-site, 5 days per week in the office

- Full-time