Principal Software Engineer

Kaystaff is Hiring for a client in NY - a Founding Principal Engineer with 5‑10+ years of experience to join as the 3rd or 4th engineer at an early‑stage startup building the operating system for psychotherapy practices.

You'll work directly with the co‑founders and own major product verticals end‑to‑end — from practice analytics and AI‑powered insights to EHR integrations. This is a high‑agency, high‑ownership role for someone who wants to build a company, not just ship features.

• Full‑stack product development across major verticals, from concept to production
• AI‑powered insights and analytics features that are core to the product experience
• EHR integrations connecting Kaystaff to the broader healthcare ecosystem
• Cloud infrastructure and system architecture as the team and product scale
• Engineering culture and practices as one of the company's founding technical hires

Requirements

• 5‑10+ years of experience, with a track record of building and shipping products 0 → 1
• Experience at either a high‑growth startup or a top‑tier tech company
• Full‑stack fluency across frontend and backend — specific languages/frameworks matter less than range and adaptability
• Experience with cloud infrastructure, AWS preferred
• Has built product‑facing analytics features
• Has shipped production features with real AI integration (not just used AI‑assisted tools to build)
• Strong system design skills, high agency, and genuine ownership mentality
• AI fluency — comfortable both building with AI and building AI into products

Compensation & Location

• Base salary up to $320K, depending on experience
• Equity: 0.5% – 1%
• Based in New York City; relocation bonuses available for candidates willing to move
• Visa sponsorship considered case‑by‑case