AfterQuery - Security Engineer

Pushes the frontier of LLMs and AI agents through novel datasets and experimentation; builds infrastructure powering frontier data creation for agentic and hard-reasoning workflows for leading AI labs and YC companies.

Comp: $200K-$350K base (depends on experience) + $250K-$500K (4-year vesting) equity. Visa: Open to visa transfers (e.g. OPT, H1B transfers). Policy: On-site, 5 days in-office in San Francisco.

Own and build AfterQuery's security posture from the ground up while contributing to core infrastructure; protect highly sensitive AI training data and workflows across integrations with leading model labs. Founding-level role.

What you'll do

• Design and implement security infrastructure across cloud/production (GCP/AWS); build the 30/60/90 day plan from scratch

• Build programmatic, scalable solutions replacing manual security workflows, incl. incident detection, response and resolution

• Secure sensitive data flows and model interaction layers unique to AI systems

• Contribute to core infrastructure and horizontal platform work when not on security

• Integrate security checks into dev workflows without slowing shipping

Tech stack: Python, Go, TypeScript, GCP, AWS, Docker/Containers

Requirements

• 4-12 yrs security + infrastructure engineering

• Deeply technical: has built security systems, not just configured off-the-shelf tools

• Comfortable moving between security work and general engineering

• On-site 5 days SF