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