Staff+ Application Security Engineer - M&A

Title: Staff+ Application Security Engineer - M&A Location: Remote-Friendly (Travel-Required) | San Francisco, CA | Seattle, WA | New York City, NY

About the role

Anthropic's Application Security team secures the systems that build, serve, and increasingly are Claude — and as Anthropic's footprint grows, that mandate now extends to companies and codebases we bring in from outside. This role establishes that function.

You'll own security due diligence and secure integration for Anthropic's acquisitions — assessing a target's security posture pre-close, writing the security risk readout for leadership, and after close, bringing acquired systems up to Anthropic's bar. Security has been part of every deal to date, but this is the first dedicated role for it: you'll formalize the playbook, the risk model, and the tooling, and make them repeatable.

This is an AppSec role first. You'll be an active member of the Application Security team — same rituals, same on-run rotation, same tooling, working alongside engineers securing Anthropic's own agentic product surfaces. The expectation is the same too: we use Claude as our primary tool, and you're expected to automate the repeatable parts of diligence and integration as you go, so each acquisition is easier than the last. When deal flow is quiet, you'll pick up core AppSec project work; when it's active, M&A is your priority.

We're upfront that the center of gravity here is M&A rather than core product security. It's burstier, more assessment-heavy, and operates on confidential, time-sensitive work. If you like parachuting into an unfamiliar codebase under time pressure and turning it into a clear risk picture for leadership, this is that job.

Key responsibilities

• Lead pre-close security due diligence on prospective acquisitions — coordinate external penetration testing, threat-model the target's architecture, assess security controls, and deliver the security risk readout for leadership ahead of close and integration planning
• Drive post-close security integration — stand up static and dynamic analysis coverage on acquired codebases, track high- and critical-severity remediation to closure, fold acquired assets into bug bounty scope, and onboard repositories to Anthropic's automated vulnerability remediation and reporting systems
• Coordinate adjacent security engineering teams (supply chain, cloud, corporate security, detection & response) on their portions of each integration
• Work across a wide set of stakeholders on every deal — corporate development, legal, security leadership, and the engineering teams inheriting acquired systems internally; engineering and security counterparts at the target company externally — translating between them and keeping the security workstream legible to all of them
• Formalize and scale Anthropic's M&A security playbook — risk-scoring model, diligence runbook, integration checklist — and turn as much of it as possible into Claude-powered tooling rather than manual process
• Share the team's operational on-run rotation (bug bounty escalations, launch consults, incident response), swapping out during periods of active deal work
• Contribute to core AppSec projects between deals — secure design reviews, threat modeling for agentic systems, and the team's security automation roadmap

Minimum qualifications

• Hands-on application and infrastructure security experience, including cloud and containerized environments
• Demonstrated ability to rapidly assess an unfamiliar codebase or architecture and produce a clear, prioritized risk assessment for a non-security audience
• Production-quality coding ability in at least one of Python, Go, Rust, or TypeScript
• Practical threat-modeling and vulnerability-identification skills — you've found and reasoned about real bugs in real systems
• Comfort operating with high autonomy, ambiguity, and tightly-held confidential context
• Clear written and verbal communication across varied audiences — executives, legal and corporate development partners, and engineering counterparts at an acquired company

Preferred qualifications

• 7+ years in application security, security consulting, or security architecture
• Prior M&A security due diligence, third-party security assessment, or technical due diligence experience
• Experience standing up or scaling SAST/DAST, bug bounty, or vulnerability management coverage across multiple codebases
• Track record of building security automation or tooling rather than relying solely on manual review
• Familiarity with using LLMs as a core part of your security workflow
• Experience securing agentic, code-execution, or LLM-integrated systems

Representative projects

• Point Anthropic's internal LLM-driven code analysis and AI-assisted scanning at an acquired repository nobody here has seen, and turn the output into a prioritized remediation plan in days rather than weeks
• Design the risk-scoring framework Anthropic uses to compare security posture across acquisitions of different shapes and sizes
• Build the automation that onboards an acquired codebase to Anthropic's vulnerability dashboard, dependency auto-patching, and bounty scope without a human running a checklist
• Write the security risk memo for a live deal and present it to corporate development and security leadership