AfterQuery

Staff Platform Engineer - Applied AI

AfterQuery

San FranciscoFullTime$300k – $400kPosted May 27, 2026

Job description

ABOUT AFTERQUERY After. Query https://www.afterquery.com/ 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, After. Query has grown well over a $100M revenue run rate.

We're based in San Francisco and backed by leading investors including Altos Ventures, Box. Group, and Y Combinator and angels from Google Deep. Mind, OpenAI, Anthropic, Meta Superintelligence Labs, and Microsoft AI. WHY APPLY Massive Opportunity: We were one of the fastest-growing YC companies in our batch, and we believe we can become one of the fastest-growing YC companies of all time.

Founding Impact: You will own and architect core infrastructure systems that power our platform from the ground up. Equity & Growth: Competitive salary and meaningful equity. As we scale, you’ll have the opportunity to shape the engineering organization and lead major technical initiatives. Strong Team: Our founding team has experience from Citadel Securities, Meta, Google, Silver Lake, and Morgan Stanley — work alongside world-class engineers and researchers.

OVERVIEW

As a Staff Platform Engineer

  • Applied AI, 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.

RESPONSIBILITIES

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