AfterQuery captures how experts reason and turns real-world professional work into high-quality training data for frontier foundation models. Backed by Y Combinator.
About the role
As a Software Engineer - Platform Infrastructure at AfterQuery, you will design and build the core infrastructure that powers our data generation, evaluation, and agentic systems. You will be responsible for the shared platforms that enable our engineers and research teams to run large-scale human-in-the-loop workflows, evaluation harnesses, and automated data pipelines used to train frontier AI models. This is a highly technical role with broad ownership.
What they're looking for
- Strong experience building production distributed systems or platform infrastructure
- Proficiency in Python and/or JavaScript (Node.js / Next.js) or similar backend technologies
- Experience designing and operating systems in cloud environments (GCP or AWS)
- Experience with message queues and event-driven systems (Kafka, RabbitMQ, Pub/Sub, etc.)
- Experience working with high-throughput data pipelines and asynchronous processing systems
- Strong understanding of system scalability, performance, and reliability
More about this role
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. Forbes reported that we could be YC's fastest unicorn, reportedly raising at a $3.2 billion valuation. 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.
Massive Opportunity: Forbes reported that we could be YC's fastest unicorn, reportedly raising at a $3.2 billion valuation, and we're not slowing down.
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...
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