Day One Partners · 10 hours ago
Founding Software Engineer (Accel/Index)
San Francisco Bay Area
Full-time
Onsite
Mid, Senior Level
$160K/yr - $200K/yr
3+ years expDay One Partners is a search firm that partners with venture capital firms to help build high-growth startups. They are seeking a Founding Software Engineer to architect and ship core messaging infrastructure, focusing on human-AI collaboration and building a developer platform that is user-friendly.
Staffing & Recruiting
Hiring Manager
Maxwell Feinberg
Responsibilities
Architect and ship core messaging infrastructure that feels instant, reliable, and magical
Focus on the invisible but critical layers — from retrieval and evaluations to performance optimization
Prototype new interaction patterns for how humans and AI agents work together
Build an API and developer platform that outside builders genuinely love using
Experiment with tool calling and retrieval systems to find what works in practice
Raise the bar for engineering craft, contribute to recruiting, and help define a world-class culture
Use our product daily, give direct feedback, and help turn insights into tangible improvements
Qualification
Required
3+ years of professional software engineering experience, with at least 1 year in a senior IC role
Proven experience building or scaling AI-powered applications
Ability to move fast without compromising quality
Strong product sense and attention to the small details that make great software exceptional
Company
Day One Partners
Like the startups we partner with, we're fresh, innovative, and poised for high growth.
11-50 employees
Funding
Current Stage
Early StageCompany data provided by crunchbase