Braintrust

Braintrust

Application Security Engineer

San Francisco

Sponsorship not specifiedDetected 76 days ago
JavaScriptPythonData EngineeringLLMsResearch

About the role

  • We're looking for an Application Security Engineer who lives in the code.

Responsibilities

  • Drive secure design across the platform: lead threat models for new features, review architecture proposals, and partner with product and backend engineers to ship features that are secure by default
  • Build the paved road: authn/authz primitives, RBAC and tenancy isolation patterns, secret handling, safe data pipelines, and sandboxed code execution for user-supplied JavaScript and Python snippets
  • Own our SAST, DAST, SCA, and secret-scanning tooling end-to-end, keeping signal-to-noise high enough that engineers actually fix what you ship
  • Partner with our open source maintainers on the security of libraries that get embedded inside customer applications
  • Track record of building secure-by-default libraries, frameworks, or services that other engineers actually adopt

Requirements

  • 5+ years in application security, product security, or backend engineering with a security focus - you've shipped real code and reviewed a lot of it
  • Deep knowledge of common web and API vulnerability classes and the architectural patterns that prevent them - not just OWASP Top 10 trivia
  • Hands-on experience with authn/authz design, multi-tenant data isolation, and secrets/key management at scale

Nice to have

  • prior experience with LLM red-teaming, agent sandbox research, or shipping security-focused open source libraries
  • A clear point of view on AI/LLM security - prompt injection, agent abuse, tool-use sandboxing, model proxy threats - and ideally hands-on experience defending against them
  • Daily user of agentic coding tools and excited to push the frontier of how AppSec gets done with them

Skills

  • prompt injection, agent sandbox escapes, tool-use abuse, and the new attack surface that comes with LLM-native applications.

Compensation

  • Competitive salary and equity

Benefits

  • Medical, dental, and vision insurance
  • Flexible time off
  • Competitive salary and equity

Company info

  • Braintrust is the AI observability platform.
  • By connecting evals and observability in one workflow, Braintrust gives builders the visibility to understand how AI behaves in production and the tools to improve it.
  • Teams at Notion, Stripe, and Vercel use Braintrust to compare models, test prompts, and catch regressions - turning production data into better AI with every release.
  • Lead AI-specific security work: prompt injection defenses, model proxy abuse detection, agent and tool-use sandboxing, data-exfiltration controls in multimodal pipelines, and security for the eval workflows our customers run

Equal opportunity

  • Braintrust is an equal opportunity employer.
  • All applicants will be considered for employment without attention to race, color, religion, sex, sexual orientation, gender identity, national origin, veteran or disability status.

This listing is sourced directly from Braintrust's careers page and normalized into a canonical job model.