Founding Engineer

Please apply via - - this is an in-person NYC position only . Any applications outside of NYC will not be reviewed. The role Sunspell is a venture lab, and this is a founding engineering seat. You build and ship end-to-end across our internal operating system and the products on top of it, from prototype to production, with agents and models as a default part of your toolkit. You care how the product feels as much as whether it runs. That range is the point. Most of your time is on our own products, with the occasional studio project. What you will do Build features and infrastructure across our operating system and the products on top of it. Take prototypes to production and own their quality, performance, and reliability. Build with agents and automations as core infrastructure, not novelty. Create reusable systems and tooling that make the next build faster. Work closely with designers to ship end-to-end. What we are looking for Around three to six years shipping software, versatile across the full stack rather than siloed in one area. Strong product sense. You understand product and shipping, and you stay open to features that look unnecessary now and prove vital later. Hands‑on experience: LLMs, agents and LangGraph, RAG, vision models, and voice, including voice LLMs and voice evals. Solid engineering discipline: test‑driven development, QA, some DevOps, and security fundamentals. We work in a lean‑startup, Scrum‑style rhythm. You ship production‑ready systems, with good judgment and an eye for the details. Comfortable with early‑stage ambiguity and a bias to ship. How we build React, Tailwind, TypeScript, and Node.js, deployed on Cloudflare. Automation tooling: mostly Claude Code, plus OpenCode and Codex. We build a lot of MCP servers, and we use GitHub throughout. You do not need our exact stack on day one; strong engineers ramp fast. Bonus, not required Harness engineering and context engineering for production agents are a huge plus. We build a lot of agents, so experience designing the scaffolding, tool loops, memory, evaluations, and context systems around models is especially valuable. Three.js and particle systems. You might be a fit even if You do not have a perfect resume, a famous logo, or a specific degree. We care more about what you have built, how you think, and how fast you learn. If your ability is ahead of your title, apply anyway. First 90 days Ship meaningful features across our operating system or a product. Stand up at least one reusable system or workflow the team adopts. Where this leads The front door is not the ceiling. Strong engineers grow into leading the platform or the technical direction of a product, with a path to run one they help prove out. Logistics Location | New York, in person, full-time. Setting | Starts as a three‑month paid contract, converting to full‑time on a fit. Contract‑first for everyone. Level | Mid‑level, around three to six years shipping software. Compensation and benefits A paid three-month contract at a rate set per person, converting to full‑time on a fit. Compensation is set by level, scope, and experience. Benefits include health coverage, top‑tier equipment, & the tools you need. Full terms are in the offer. #J-18808-Ljbffr