There is a strong emphasis on experimentation and novel datasets to push the frontier of LLMs and AI agents.
Founding Software Engineer
San Francisco · On-site$150k – $240k + EquityVisa Sponsorship Available
About this role
AfterQuery is building the next generation of AI evaluation tools. You will own end-to-end projects within a collaborative engineering team, tackling a range of tasks from research-driven prototyping to scalable production systems. This role matters because you’ll directly impact how AI capabilities are evaluated and deployed across real-world workflows.
What youll do
- Design and build scalable systems: RL environments, APIs, and human-in-the-loop platforms.
- Collaborate across research, product, and design to ship features quickly.
- Write clean, maintainable code and contribute to documentation.
- Participate in code reviews and design discussions.
- Solve real-world scalability and reliability challenges.
- Contribute to the core infrastructure powering data and evaluation for leading AI labs.
What AfterQuery is looking for
- AfterQuery requires experience with Next.js, React, and Kubernetes
- AfterQuery requires experience with DevOps practices
- AfterQuery requires willingness to be in office in SF 5 days a week (Mon - Fri) and online/remote on Sundays
- AfterQuery requires experience at S-tier VC-backed startup, reputable trading firm, big tech (MAANG/Bloomberg/etc), or founding engineer from YC or company that has raised $2.5M+
- AfterQuery requires proficiency in Python, JavaScript, and TypeScript
- AfterQuery requires 2+ years in Full-stack Software Engineering positions
- AfterQuery requires experience with Kafka, Redis, or Elasticsearch
- AfterQuery requires experience at a high-growth startup
- AfterQuery seeks strong CS fundamentals
Company at a glance
AfterQuery builds datasets and experimentation to advance frontier LLM and AI-agent workflows, constructing complex data-infrastructure for agentic and hard-reasoning tasks. It partners with five AI labs and is YC's infrastructure partner, led by teams from top banks and quant firms.
IndustryData Infrastructure and Analytics
Team Size11-50
WorkspaceOn-site
StageSeries A
Founded2025
Location
San Francisco, United States
Investors
Altos Ventures ·BoxGroup ·Latitude Capital ·Raine Ventures ·Y Combinator
Websiteafterquery.com
LinkedInLinkedIn
Culture & values
The work culture centers on solving complex, frontier-scale technical challenges in data infrastructure for agentic and hard reasoning workflows.
The company collaborates with all five leading AI labs, indicating a collaborative, cross-organizational culture.
The company is experiencing a sharp hockey-stick growth rate, suggesting a fast-paced, high-velocity work environment.
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