US Job Posting Template
Core
Design, build, and scale customer-facing payment APIs and critical systems for Block's payment products (Square, Cash App, Afterpay) to process worldwide payment traffic reliably and securely.
Role type
Senior IC Backend Engineer (Payments Infrastructure)
Builds
High-volume, distributed payment APIs and services
Domain
Fintech / Payments / Distributed Systems
Deliverable
production ML models | product features
Required skills
Payments domain expertise, Distributed systems design, API design & versioning, Incident response & on-call, Performance optimization, Security engineering, AI-assisted development, Technical leadership, System reliability, Automation
Preferred skills
Kotlin, Go, TypeScript, AWS, Kafka
Technologies
Kotlin, Go, TypeScript, AWS, Kafka
Responsibilities
Design and maintain scalable payment APIs with clear contracts; Lead complex projects from requirements to production; Operate critical systems and participate in on-call rotation; Improve observability, fault tolerance, and security; Use AI tools for design, implementation, and debugging while validating output; Mentor engineers through code and design reviews.
Seniority
Senior, hands-on IC