Senior Product Security Engineer

At Affirm, we exist for the moments that matter—giving people a clear, predictable way to pay over time, with no hidden fees, no surprises, and no tradeoffs on what matters most. About the InfoSec team The InfoSec team protects Affirm’s systems and data from evolving threats. We manage security risk, monitor vulnerabilities, and enforce protective controls across the company. The team leads incident response, compliance, identity and access management, and employee training. Our goal is to ensure that security is built into every system and decision at Affirm. We maintain a secure, trustworthy environment so the business can operate and grow with confidence. About the role In this role, you'll help mature Affirm's insider threat program. You'll build out the controls, detection use cases, and investigative practices that make it work day to day, support insider risk investigations, and partner with Legal, HR, Privacy, and Compliance to keep the program effective, proportionate, and trusted by Affirmers. What you’ll do • Lead the build-out of key insider threat workstreams, from initial design through to day-to-day operation • Build out the program's operating mechanics, including investigative standards, playbooks, and the metrics and reporting that show whether the program is working • Support insider risk investigations alongside SIRT, bringing insider threat expertise, telemetry and evidence analysis, and written findings and risk recommendations • Partner with Legal, HR/Employee Relations, Privacy, and Compliance on case handling and escalation criteria, helping ensure the program respects employee privacy and meets legal and regulatory obligations • Threat model Affirm's highest-risk data and systems for insider risk, and partner with detection engineers to turn the results into production detections • Own and improve the controls that reduce insider risk, including data loss prevention, endpoint monitoring, secure browser and contractor access controls, SaaS posture management, and access governance, working with system owners to close gap • Automate the program's operational load with workflow automation platforms and Python, covering evidence collection, case routing, and reporting • Build and expand agentic automations that assist with insider risk triage and investigation, and define which decisions stay with a human What we look for • Deep expertise in security engineering, security operations, insider risk, or digital forensics • Track record of standing up new security capabilities where little existed before • Experience running investigations end to end, including evidence handling, log and endpoint forensics, timeline reconstruction, and written findings suitable for Legal and HR audiences Ability to write and evaluate detection logic against endpoint, identity, cloud, and SaaS telemetry in a SIEM (Splunk, Elastic, Panther, Chronicle, or similar) • Hands-on experience with insider risk tooling such as DLP, UEBA, endpoint detection and response, CASB, and access governance, with a practical sense of their strengths and limits • Working knowledge of Python for security tooling and automation • Experience building and maintaining production workflows in automation platforms such as Tines, Torq, or similar • Experience building and running agentic automations in production that assist with alert triage and investigation, such as LLM-driven enrichment, summarization, or first-pass analysis, with a clear view of where human review stays in the loop • Discretion and sound judgment handling sensitive investigations, and comfort navigating the privacy, legal, and employee-relations considerations that insider work carries • Clear written and verbal communication skills, with the ability to work across