Senior Fullstack Engineer- Auth Team

About the Role

As a Senior Full Stack Engineer on the Platform Team, you will develop and operate Alpaca’s authentication, authorization, and Identity Provider (IdP) systems - the systems that handle user login, access control, and secure access across our APIs, customer products, and internal tools.

We are looking for experienced engineers who are comfortable owning services end to end: API design, data modeling, deployments, and production debugging. Most of your time will be spent writing Go (backend services, gRPC/REST APIs, shared client libraries), with meaningful work in React/TypeScript for auth-related UI, and occasionally Java for identity-provider extensions. You will also work with Helm charts, analyze logs and metrics, manage deployments, and help other teams to integrate with our services.

Things You Get To Do

• Build and improve authentication-related experiences in customer and partner web applications, including login, permissions, and credential management.
• Develop and maintain the platform’s authentication, authorization, and IdP services.
• Create and evolve shared libraries and SDKs.
• Integrate with identity providers and keep login and access policies working reliably across products.
• Deploy, monitor, and troubleshoot identity services in production.
• Help modernize legacy authentication patterns as the platform evolves.
• Own work end to end, from requirements through delivery and follow-up.
• Collaborate with other engineering teams on identity and access integration.
• Maintain high code quality, write tests, and participate in code reviews.
• Help investigate incidents and bugs, including on-call rotation.

Who You Are (must-haves)

• You have 5+ years of experience writing code in strongly-typed languages, with at least one year of experience in Go.
• You have experience building web applications with React and TypeScript.
• You have worked with relational databases before - we use PostgreSQL, but we are not particularly picky about this one as long as you have a solid grasp on the fundamentals.
• You have worked at a startup before - you thrive in ambiguous environments, embrace changing priorities, know when to balance technical debt with speed, and proactively tackle whatever needs to get done without relying on pre-existing processes or documentation.
• You are not afraid of taking a task from start to finish - gathering requirements, figuring out and implementing the best technical solution, then deploying and monitoring the results.
• You have worked at least 3 years on systems at scale.

Who You Might Be (nice-to-haves)

• You know what a JWT token is, and how OpenID Connect and SAML work. Maybe you even heard about Keycloak, or have worked on authentication systems before.
• You have experience with role-based access control.
• You have built or maintained OpenAPI-driven HTTP APIs.
• You are familiar with Kubernetes and Helm.
• You have experience with Java.
• You understand how Kafka works - maybe you even worked with Redpanda before.
• You have experience with Grafana’s observability stack - Prometheus, Tempo and all the rest. You might have even written a PromQL query for a new alert once or twice.