Senior Software Engineer (Backend, Consumer Authentication Platform)

Join Affirm's Consumer Authentication Platform team as a Senior Software Engineer. In this role, you will build secure and reliable authentication experiences that connect millions of consumers with Affirm's financial products. You will lead significant technical initiatives, influence the architecture and evolution of the platform, and help deliver secure authentication capabilities. You will also collaborate with various teams, translate requirements into technical designs, and support the operations and availability of your team's artifacts.

Lead significant technical initiatives and influence the architecture and evolution of the authentication platform.

Responsibilities

• Own the technical design and delivery of significant authentication platform capabilities, leading projects from early requirements to ongoing operation.
• Collaborate with product management, Security, Fraud, Compliance, design, and analytics; participate in ideation; articulate technical constraints.
• You are proficient at making significant changes in a large codebase and have developed a suite of tools and practices that enable you and your team to do so safely, including testing strategies, migration plans, and controlled rollouts

Requirements

• Experience designing session-management, token-issuance, account-recovery, or multi-factor authentication systems. Familiarity with risk-based or adaptive authentication and the interaction between identity, security, compliance, and fraud controls
• This position requires either equivalent practical experience or a bachelor’s degree in a related field
• Your experience demonstrates that you take ownership of your growth, proactively seeking feedback from your team, manager, and stakeholders, while helping other engineers grow through mentorship and technical leadership
• Familiarity with standards and protocols such as OAuth 2.0, OpenID Connect, WebAuthn/passkeys, FIDO2, JWTs, and public-key cryptography. Knowledge of security and assurance frameworks such as the NIST Digital Identity Guidelines or PCI DSS
• You have a track record of developing highly available distributed systems using technologies like AWS, MySQL, and Kubernetes, as well as relational databases, event-driven architectures, and RPC or API frameworks
• You have 4+ years of experience designing, developing, and launching backend systems at scale using languages like Python, Kotlin, Java, or another comparable modern programming language
• You have experience defining a technical plan for the delivery of a significant feature or system component with an elegant, secure, simple, and extensible design. You write high-quality code that is easily understood and used by others
• You have strong verbal and written communication skills that support effective collaboration with our global engineering team and cross-functional partners