Founding AI Platform Engineer

Day One Partners; San Francisco (CA); On-site; USD 150,000 - 210,000; Full time

Benefits offered by this job

Founding-stage equity

Flexible medical benefits

Health & wellness perks

Job summary

Day One Partners seeks a Founding Product Engineer to join a stealth-to-launched startup redefining workplace communication for the AI-agent era. You’ll own major areas end to end, shape product direction, architecture, and the engineering culture with the founder and early team.

You’ll help build a fast, memory-rich messaging platform designed for humans and AI agents, with proactive orchestration, developer tooling, and sandboxed infrastructure, shipping rapidly in a high-ownership environment.

Qualifications

• 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.

Responsibilities

• Architect and ship core messaging infrastructure that is fast, reliable, and delightful to use.
• Build state-of-the-art memory and retrieval systems for persistent human-agent collaboration.
• Design and develop a proactive agent orchestration layer.
• Build the MCP/API, agent developer platform, and sandbox infrastructure used by outside developers.
• Experiment with tool use and new interaction patterns for humans and AI agents working together.
• Make foundational product and architecture decisions as an early member of the engineering team.
• Raise the bar for engineering craft, contribute to recruiting, and help shape the engineering culture.
• Dogfood the product every day and turn firsthand insights into product improvements.

Skills

Software engineering

AI-powered apps

Speed and quality

Job description

Day One Partners seeks a Founding Product Engineer to join a stealth-to-launched startup redefining workplace communication for the AI-agent era. You’ll own major areas end to end, shape product direction, architecture, and the engineering culture with the founder and early team.

You’ll help build a fast, memory-rich messaging platform designed for humans and AI agents, with proactive orchestration, developer tooling, and sandboxed infrastructure, shipping rapidly in a high-ownership environment.