Principal Software Engineer, Product Security

SentiLink stops more than 150,000 fraud attempts and verifies more than 3 million identities every day to protect both institutions and consumers. The problems we work on are challenging, and solving them takes deep domain expertise, rigorous analysis, and a willingness to dig into the details. At SentiLink, you'll work alongside smart, highly collaborative colleagues who respect each other's time and judgment, take ownership, and follow through on their commitments. Together, we do truly meaningful work protecting the identities of innocent consumers and flagging the fraudsters attempting to exploit them. We're well capitalized and growing quickly. We already serve 13 of the top 15 U.S. banks, we're expanding into new markets, and we're backed by Craft Ventures, Andreessen Horowitz, NYCA, and Max Levchin. We've been named to the Forbes Fintech 50 and as a 2026 FICO Industry Vanguard Decision Award Winner. We were also the first company to go live with the electronic Consent Based Social Security Number Verification (eCBSV) service, and we've testified before the U.S. Congress on the future of identity. We want SentiLink to be the best place you've ever worked. We offer generous benefits and support a range of working arrangements, from fully remote to in-office. We are a digital-first company with strong collaboration across the U.S. and India, and we meet in person regularly to build relationships. We have offices in Austin, San Francisco, New York City, Seattle (Bellevue), Los Angeles, and Chicago in the U.S., and in Gurugram (Delhi) and Bengaluru in India. Role We’re looking for a Principal Software Engineer, Product Security to lead and elevate security across SentiLink’s infrastructure, applications, and internal systems. This is a highly technical, hands-on role focused on building scalable security foundations while enabling the business to move quickly and safely. You will partner closely with Engineering, Infrastructure, Product, Legal, and Compliance teams to design secure systems, improve detection and response capabilities, strengthen cloud security posture, and reduce organizational risk. You’ll help shape long-term security strategy while remaining deeply involved in technical implementation and operational execution. This role is best suited for someone who combines strong technical depth with practical judgment and thrives in fast-moving, high-ownership environments. Responsibilities Design and build internal security tooling from scratch, including agent-based security tooling, code analysis tooling, dynamic scanning, and security assessment toolsIdentify vulnerabilities across SentiLink's AWS-based stack, including application code, cloud service configurations, and integrations between the twoDevelop AI-assisted and agent-based tooling to scale offensive security testing beyond what a small team can do manuallyBuild and maintain security automation that improves detection, response, and remediation across the organizationConduct hands-on penetration testing and vulnerability research against SentiLink's infrastructure and applicationsPartner with engineering teams to remediate findings and embed security into the development process without slowing them downParticipate in the security on-call rotation, including incident response and regular response testingContribute to threat modeling and security design reviews for new systems, with a focus on cloud integrations and identity flowsStay current on offensive security techniques, AI-assisted security tooling, and emerging attack patterns relevant to fintech and identity verification Requirements 8+ years of experience in security engineering, software engineering with a security focus, or closely related rolesProficient in at least one systems language (Go, Rust, C++) and at least one higher-level language (Python, TypeScript)Proven ability to design and ship production software end-to-endDeep AWS infrastructure expertise, including IAM, EKS, RDS, networking, and managed servicesDemonstrated ability to identify security misconfigurations and vulnerabilities across cloud architectures, application code, and the integrations between themExperience conducting or building tooling for penetration testing, vulnerability assessment, or red team activitiesTrack record of building security automation and tooling from scratchComfortable operating independently on ambiguous problems without heavy process or oversightStrong communication skills and the ability to partner with engineers who are not security specialists Nice To Have Experience building or deploying LLM-based agents or AI-assisted security toolingPrior experience at a security product company (Wiz, Snyk, Datadog, etc.) or other security-forward engineering orgPrior fintech, identity, or fraud detection experienceIndustry certifications (OSCP, OSCE, GPEN, GXPN)Experience with detection engineering or SIEM platformsPublished security research, CVEs, or open source security tooling contributionsExperience supporting compliance frameworks (FedRAMP, SOC 2, PCI DSS) without it being their primary focus Compensation $220k-280k/year + equity + benefits Perks Employer paid group health insurance for you and your dependents401(k) plan with employer match (or equivalent for non US-based roles)Flexible paid time offRegular company-wide in-person eventsHome office stipend, and more! 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