Lead Application Security Engineer

About the Role As the first dedicated security hire, you will shape application security for a growing B2B data infrastructure platform. This is a hands-on individual contributor role focused on solving high-impact security challenges in distributed systems and helping product engineering teams build securely as the company scales. What You'll Do Improve tenant isolation and authorization models, including access controls for multi-team and multi-brand use cases. Design and strengthen security architecture for compute isolation, and threat model and harden new products. Improve rate limiting, abuse detection, and granular access controls for high-throughput, internet-facing APIs. Support multi-region and multi-cloud infrastructure, including technical controls for data residency. Identify the highest-impact security risks, own your roadmap, and implement production fixes in collaboration with product engineering teams. What We're Looking For Six or more years of security engineering experience, with deep knowledge of distributed systems and recent hands-on production coding experience. Prior backend software engineering experience building production APIs, distributed systems, or data pipelines. Experience as an early security hire at a SaaS or data infrastructure company, and experience helping a venture-backed or high-growth technology company scale. Experience securing multi-tenant platforms, including tenant isolation and authorization, and systems spanning multiple cloud providers or regions. Security engineering experience that includes defensive responsibilities, plus familiarity with privacy controls such as PII handling, GDPR, or CCPA. A degree in computer science, mathematics, physics, or a related field. Relevant technologies include TypeScript, Go, AWS, Azure, and GCP. Compensation & Benefits Base salary: $220,000 to $320,000 annually. Visa sponsorship is available. Location Remote, United States.