Staff Platform Engineer

Job Overview

AfterQuery is an applied research lab curating data solutions for foundation model development. We serve every frontier AI lab with the mission of delivering the best data to power the best models. In doing so, we can make expertise that once took a lifetime to build available to anyone who needs it. Our customers are the ones building the foundation models themselves and our work sits directly in the loop of how those systems improve.

This is a rare opportunity to join a company at a defining moment in AI. Since raising our $30M Series A at a $300M valuation, AfterQuery has grown well over a $100M revenue run rate. We're based in San Francisco and backed by leading investors including Altos Ventures, BoxGroup, and Y Combinator and angels from Google DeepMind, OpenAI, Anthropic, Meta Superintelligence Labs, and Microsoft AI.

Staff Platform Engineer - Applied AI

Location: San Francisco
Type: Full-time, On-site

We’re hiring an Staff Platform Engineer - Applied AI who’s a strong IC and manager. You’ll lead engineers, stay hands-on in the code, and drive execution across critical systems. This is an ownership role, not a coordination role.

Key Responsibilities

• Team Leadership: Manage a small group of engineers and own their output end-to-end


• Hands-on Development: Write code, review systems, and contribute directly to critical builds


• Execution: Drive projects forward quickly while maintaining a high bar for quality


• Hiring & Mentorship: Recruit, mentor, and develop engineers to raise the overall team bar


• Technical Ownership: Ensure systems are scalable, clean, and reusable


• Cross-functional Collaboration: Work closely with ops, domain experts, and customers


• 60/40 Split between building + managing engineers

Required Qualifications

• Strong background as a staff-level or higher engineer


• Experience managing or leading high-performing engineering teams (5–15 engineers)


• Proven ability to ship production systems in fast-paced environments


• Comfort operating in ambiguous, rapidly changing contexts


• Desire to remain hands-on with code and system design

Not a Fit If

• You don’t want to code anymore


• You need a lot of process or structure


• You’ve been far from the code for a while