Senior Software Engineer, Identity Platform

Upstart is an AI lending marketplace focused on reducing the cost and complexity of borrowing through advanced technology. The Senior Software Engineer will build and secure scalable authentication, authorization, and experimentation systems for the company’s lending products, while collaborating with Engineering, Product, and Security teams to improve identity management and user experiences.

Responsibilities:

• Design, develop, and optimize secure and scalable authentication and authorization systems
• Collaborate with cross-functional teams to improve Identity and Access Management (IAM) capabilities, including OAuth, OpenID Connect, MFA, and SSO
• Partner with Security teams to enhance security policies and standards, ensuring protection against threats and unauthorized access
• Improve Experimentation platform and Lifecycle across the Upstart Network Inc Products
• Drive best engineering practices for clean, maintainable, and efficient code
• Participate in architectural discussions, helping to shape the long-term vision of Identity Platform
• Mentor and collaborate with other engineers to elevate the team’s technical skills and knowledge
• Work on high impact initiatives that solve for making credit accessible to everyone

Requirements:

• Bachelor's degree in Computer Science, Engineering, or Mathematics, or a related field (or its equivalent) + 4 years of experience
• Strong proficiency in backend technologies (e.g., Kotlin, Java, Ruby, C#)
• Hands-on experience with authentication and authorization protocols (OAuth 2.0, OpenID Connect, SAML)
• Experience building scalable APIs using containerization technologies like Docker and Kubernetes
• Understanding of security principles, including encryption, token-based authentication, and identity federation
• Strong problem-solving and debugging skills, with an emphasis on performance optimization
• Ability to balance the needs of the business with engineering best practices and security considerations
• Passion for clean code, architecture, and continuous improvement of engineering processes
• Experience with AI Coding tools such as Cursor, Claude Code etc
• Excellent communication skills – able to translate complex technical concepts for a variety of stakeholders
• Experience working with IAM platforms and security services
• Knowledge of A/B testing, gRPC, and DevOps practices
• Experience with Keycloak, NextJS, and Ruby is a plus
• Proven ability to influence technical direction without direct authority
• Strong product and analytical mindset, capable of making trade-offs between risk, ROI, and performance
• Experience working at companies experiencing rapid growth and scaling challenges
• Strong sense of ownership and accountability for the quality and timely delivery of work
• Ability to influence and lead without direct authority