Founding Product Engineer

This role is for a founding product engineer who will live and work alongside the founders to build core features, shape the architecture, and own outcomes from day one; you'll join a small, fast-paced team where product judgment and rapid execution matter. The position blends hands-on full‑stack engineering with user research, design sensibility, and heavy use of AI tools to accelerate delivery and quality.

What you'll do

• Build and ship core product features end-to-end with high autonomy.
• Work side-by-side with the founders, living in a hacker house and collaborating tightly.
• Use AI tools (e.g., Cursor, Claude Code, Codex, agent workflows) as part of daily development to move faster and maintain quality.
• Talk to users constantly to find bottlenecks and ship fixes quickly.
• Propose and prototype new features, products, and internal tooling.
• Help set engineering standards, architecture, and the company pacing.
• Take deep ownership of projects, driving solutions from conception through follow-through.

What Sparkles is looking for

• 1–5 years shipping real product software is a baseline, with flexibility for exceptional candidates.
• Strong TypeScript and React skills and the ability to build full-stack product features.
• Heavy AI-tool usage as part of your real workflow, not as a novelty.
• Strong product instincts, good design taste (Figma fluency a plus), and a bias toward outcomes.
• High agency: you notice problems, propose solutions, and drive them to completion.
• Comfortable with ambiguity and moving at founder speed in a startup environment.
• Experience with realtime or collaborative systems (Cloudflare Workers, Durable Objects, service bindings) and/or building devtools, sandboxed, or safety-sensitive systems is a plus.
• Background at a strong startup or equivalent evidence of ownership, rapid output, and strong judgment.
• Awesome salary, meaningful equity, an incredible team, and a world-class product.