AfterQuery - Security Engineer

deCircle; San Francisco (CA); On-site; USD 200,000 - 350,000; Full time

Job summary

deCircle is seeking a founding-level security and infrastructure engineer to own and build the security posture from the ground up, protecting highly sensitive AI training data and workflows across integrations with leading model labs.

You will design scalable security infrastructure and bridge security with development, contributing to core platform work as needed, all while based on-site in San Francisco.

Qualifications

• 4–12 years of security and infrastructure engineering experience.
• Deeply technical and capable of building security systems from scratch.
• Comfortable switching between security work and general software engineering.
• On-site work in San Francisco, five days a week.

Responsibilities

• Design and implement security infrastructure across cloud/production (GCP/AWS).
• Build scalable security workflows including incident detection, response, and resolution.
• Secure sensitive data flows and model interaction layers in AI systems.
• Contribute to core infrastructure and horizontal platform work when not securing.
• Integrate security checks into dev workflows without slowing shipping.

Skills

Security engineering

Infrastructure engineering

Cloud security

DevSecOps

Tools

Python

Go

TypeScript

GCP

AWS

Docker/Containers

Job description

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

• 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