Founding Software Engineer Fast-growing consumer software company New York $150k to $250k USD base a year

raydar; New York (NY); On-site; USD 150,000 - 250,000; Full time

Benefits offered by this job

Equity

Competitive base salary

Job summary

Raydar is seeking a founding software engineer in New York City to own the design and delivery of core application and backend features for a widely used consumer product. You will work directly with company leadership on applied AI systems and the infrastructure behind them in a compact, in-person environment.

You will build an agentic framework, ship your own product with measurable impact, and help scale tooling and GPU infrastructure in a lean, founders-led team in NYC.

Qualifications

• Strong full-stack or backend engineering background.
• Hands-on experience building agentic systems with memory and prompts.
• Experience with open-source LLMs (serving, fine-tuning, evaluation).
• Track record shipping own product with measurable results.
• Public code portfolio demonstrating recent activity.
• Excellent communication and ownership in lean teams.

Responsibilities

• Build and refine core AI agent framework including tool use, memory, prompting, retrieval, and evaluation.
• Take features from architecture through launch and ongoing iteration across app and backend services.
• Collaborate with founders to shape a simple, polished user experience.
• Extend capabilities with sandboxed tooling and scalable backend/database infrastructure.
• 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.
• Contribute to future product initiatives as the company grows.

Skills

Full-stack engineer

Back-end

Agentic systems

Open-source LLMs

Product shipping

Public code portfolio

Effective communication

Ownership in lean teams

Job description

# Founding Software EngineerFast-growing consumer software company* LocationNew York* TypeFull-time* Posted16 October 2026Apply for this roleTalk to us firstYou apply on Workable, where Raydar manages applications.The role, as published## About the companyOur client is a fast-growing consumer software company.## The roleRaydar 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.## 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.## Location and work model* New York, NY, United States* On-site, 5 days per week in the office* Full-time## Compensation, as the posting describes it* EquityPay$150k to $250kUSD base a year