Block's Access team is building the next generation of authentication and permissions infrastructure to enable Cash App and Block's ecosystem to scale while serving increasingly diverse customer needs, as product innovation leads to an explosion of new use cases and requirements.
Requirements
- 5+ years building and operating production systems with demonstrated impact and technical ownership
- Experience with authentication, authorization, or identity systems
- Experience working in large codebases and breaking apart monoliths
- Background in security, fraud prevention, or trust & safety domains
- Experience building platform or infrastructure that other engineering teams depend on
- Java, Kotlin, Golang
- HTTP, JSON, gRPC, Protocol Buffers
Responsibilities
- Design and build the APIs and services that power Authentication & Permissions across Cash App and Block's ecosystem, the systems that determine who can access what, and how they prove they are who they say they are.
- Build fine-grained permissions systems that enable different roles and capabilities across various account configurations
- Build secure authentication experiences that protect customers while maintaining seamless access to their accounts
- Improve account recovery success rates, helping legitimate customers regain access while keeping bad actors out
- Consolidate authentication platforms, migrating critical flows into scalable, composable services
- Design authorization primitives that product teams across Block can use to build secure, flexible experiences
- Solve complex technical problems that directly impact both customer trust and product velocity.
Other
- Ability to think critically and analyze complex problems, weigh trade-offs, and make pragmatic decisions that balance competing priorities
- A bias toward iterative delivery. You know how to break big problems into shippable pieces and maintain momentum through ambiguity
- Comfort with complexity. Whether it's large codebases, distributed systems, or evolving requirements, you don't get overwhelmed; you get strategic
- Excellent communication skills. You can explain technical concepts clearly, build alignment across teams, and adapt your style to different audiences
- Customer empathy. You understand that behind every API call is a person trying to access their money, and that matters
