Founded in 2018, Persona is a 250-person tech startup based in San Francisco, backed by top-tier investors. They offer flexible building blocks to help businesses fight fraud, stay compliant, and build trust among customers. As a Senior Software Engineer in Security, you'll own security-sensitive libraries and components of the production platform. Your mission will be to design, build, and maintain security libraries and systems to protect customers' accounts and data. You'll work on encrypting customer data, refining authentication and authorization components, and proposing new security features. This role requires 5+ years of security software engineering experience, a passion for security, product thinking, an innovative mindset, proactive thinking, and a collaborative spirit. You'll be based at the San Francisco headquarters, with relocation assistance available. Persona offers competitive compensation, including equity, and best-in-class benefits such as 401K matching, parental leave, unlimited PTO, and wellness stipends. The company is recognized as one of Fortune's Best Medium Workplaces, emphasizing their commitment to fostering a world-class team and valuing people above all else.