Founding Software Engineer

AfterQuery is helping push the frontier of LLMs and AI Agents through novel datasets and experimentation. We work on building the most complex infrastructure that powers frontier data creation for agentic and hard reasoning workflows. We work with all 5 of the leading AI labs and are becoming the go-to partner for data infrastructure for YC companies. We have a sharp hockey stick growth rate and are extremely talent-dense, with most of our founding team coming from top IB and quant firms.

As part of AfterQuery’s engineering team, you’ll have end-to-end ownership over projects that push the frontier of AI evaluation. You’ll work on a mix of research engineering (designing novel RL environments, agentic systems, evaluation harnesses) and platform engineering (building human-in-the-loop platforms, scaling data infrastructure, designing annotator workflows).

This is not a narrow role. One week you might prototype a new RL environment from a research paper, the next you’ll be deploying distributed experiments on Kubernetes, and the week after you’ll be improving the reliability of our Next.js dashboards or building a Kafka pipeline for annotator analytics.