Staff Software Engineer, Identity & Authorization

Title: Staff Software Engineer, Identity & Authorization Location: Foster City, CA Replit is the agentic software creation platform that enables anyone to build applications using natural language. With millions of users worldwide, Replit is democratizing software development by removing traditional barriers to application creation. ABOUT THE TEAM Product Platform builds and owns the shared foundations the rest of Replit is built on, spanning the full stack so every other team can ship features safely and quickly. Identity & Authorization defines how people, agents, sandboxes, and services prove who they are and what they can do. These systems protect critical product and service interactions across Replit's web product, Agent, enterprise controls, and internal services. Our work is high-leverage and horizontal: when identity and policy are clear, reliable, and easy to adopt, every other team can move faster without rebuilding security controls. We are a small, collaborative team that values curiosity and clear thinking over pedigree, and we work in the open by bringing each other the problem rather than just the request. We care more about how you reason and build than the route you took to get here. ABOUT THE ROLE As a Software Engineer, you will design, build, and operate the identity and authorization systems that protect critical interactions on Replit, including Agent acting on behalf of a user or holding their own identity. The work is guided by a few simple questions: - Can every protected request prove which workload made it, which principal it represents, and who is acting on that principal's behalf? - Can product teams express policy once and trust the same decision across web, mobile, Agent, and internal services? - Can enterprise administrators control who can access each workspace, app, connector, and Agent capability without navigating a permission maze as well as having a legible ledger of decisions? - Can Agent act for a user across long-running and durable work without receiving broad or long-lived credentials? - Are identity and authorization fast, reliable, highly available, and observable enough for the product flows that depend on them? WHAT YOU'LL DO - Design and operate central authorization interfaces with typed principals, actions, resources, decisions, explainable deny reasons, privilege attenuation, delegations, and obligations - Evolve enterprise roles, groups, app access, entitlements, and workspace policy so common cases stay simple and advanced cases remain possible - Build and operate Replit's Security Token Service and workload identity using OAuth 2.0 token exchange, JWT/OIDC, SPIFFE/SPIRE, and mTLS - Threat-model delegation, confused-deputy risks, and cross-tenant movement, then make secure, fail-closed behavior the default - Lead compatible migrations with shadow evaluation, feature gates, telemetry, and rollback plans, and own the SLOs, incidents, and operational health of the systems you ship - Partner with Agent, Connectors, Enterprise, Security, and Infrastructure teams to turn product requirements into shared platform primitives - Research and develop new innovative approaches to Authx in the Agentic world AREAS YOU MIGHT WORK IN - Authorization policy: evolve Replit's central policy decision point and migrate fragmented authorization checks to its typed contract. - Agent delegation: extend the current delegation foundation so the user is the subject and Agent is the authenticated actor, with continuous validation and dynamic permission envelopes as work runs. - Enterprise access control: evolve roles, groups, workspace policy, and app-level grants for both simple collaboration and complex organizations. - Agent and service identity and reliability: operate the token and workload-identity systems that protect service-to-service traffic. REQUIRED SKILLS AND EXPERIENCE - Experience shipping and operating security-sensitive backend or distributed systems in production, including reliability, performance, incidents, and observability - Depth in authentication, authorization, or identity systems, such as OAuth 2.0/OIDC, JWT, mTLS, Identity Federation, RBAC, ReBAC, PBAC, Zanzibar, Macaroons, Biscuits, Cedar, or policy engines. You do not need prior experience with every item - Strong understanding of multi-tenant security, least privilege, delegation, privilege attenuation, auditability, and threat modeling - Experience migrating security-sensitive systems without breaking callers. Approaches can include typed contracts, shadow evaluation, and staged enforcement - Fluent in at least one production backend stack. Our systems use TypeScript, Go, Rust, Postgres, gRPC/Protobuf, Kubernetes, Envoy, and Restate - Able to make and communicate tradeoffs across security, reliability, latency, product experience, delivery speed, and long-term maintainability If you're excited about this role but don't meet every requirement, we still encourage you to apply. Full-Time Employee Benefits Include: 💰 Competitive Salary & Equity 💹 401(k) Program with a 4% match (US Only) ⚕️ Health, Dental, Vision and Life Insurance 🩼 Short Term and Long Term Disability 🚼 Paid Parental, Medical, Caregiver Leave 🏝 Flexible Time Off (FTO) + Holidays 🚗 Commuter Benefits (In-Office & US Only) 📱 Monthly Wellness Stipend 🧑‍💻 Autonomous Work Environment 🖥 In Office Set-Up Reimbursement (In-Office Only) 🚀 Quarterly Team Gatherings ☕ In Office Amenities (In-Office Only) Want to learn more about what we are up to? - Self-driving Company - Replit Agent at Scale - AI Adoption - Build Open-Source Apps Interviewing + Culture at Replit - Operating Principles - Reasons not to work at Replit To achieve our mission of making programming more accessible around the world, we need our team to be representative of the world. We welcome your unique perspective and experiences in shaping this product. We encourage people from all kinds of backgrounds to apply, including and especially candidates from underrepresented and non-traditional backgrounds.