About AfterQuery
AfterQuery builds the training data and evaluation infrastructure that frontier AI labs use to make their models better. We work with the world's leading labs to design high signal datasets and run rigorous evaluations that go beyond static benchmarks. We are a small, early team (post Series A) where individual contributors have a direct impact on how the next generation of models learn and improve.
The Role
As a SWE (Environments), you will design the datasets and evaluation rubrics that directly influence how frontier models learn. You'll work hands-on with research teams at top AI labs, experimenting with data collection strategies, diagnosing model failure modes, and developing the metrics that determine whether a model is actually improving. You'll go from hypothesis to live experiment quickly, and your output will feed directly into model training runs at scale.
Day to day, you will design data slices that expose meaningful failure modes across domains like finance, code, and enterprise workflows. You will build and refine reward signals for RLHF and RLVR pipelines. You will develop quantitative frameworks for measuring dataset quality, diversity, and downstream impact on alignment and capability. You will partner with lab research teams to translate their training objectives into concrete data and evaluation specifications.
What You'll Do
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 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.
Research Scientist - Post-Training
Technical Recruiter
Senior Platform Engineer, Applied AI
Staff Platform Engineer, Applied AI
Software Engineer (Security)
Salary
$180,000 - $220,000
Location
San Francisco, United States
Experience
3+ years
Total raised
$34.0M
Last stage
Series A
Investors
No applications, no recruiter spam. Just the intro.
A few questions to make sure this role is the right shape for you. Two minutes.
I write the intro, send it to the founder, and handle the back-and-forth.
If they’re a yes, I book the chat. You show up — that’s the whole job-hunt.