Senior Payments API Engineer

Block; Bay (AR); On-site; USD 185,000 - 278,000; Full time

Job summary

Block, Inc. is seeking an experienced software engineer to design, build, and scale customer-facing payment APIs and the critical systems behind them.

You will lead complex projects end to end, own testing and rollout, and help shape the team’s technical direction while maintaining production systems and on-call responsibilities. You will work across Block’s payment platforms, ensure security and reliability, and leverage AI-assisted tooling to improve quality and delivery.

Qualifications

• Experience building, maintaining, and scaling customer-facing financial or payment APIs.
• Experience designing and operating high-volume, highly available distributed systems.
• Understanding of idempotency, retries, asynchronous processing, and partial failures in payments.
• Led complex engineering projects from unclear requirements to production.
• Experience diagnosing production issues with monitoring and incident response.

Responsibilities

• Design, build, and scale customer-facing payment APIs with clear contracts and predictable behavior.
• Lead complex projects end to end, planning delivery and owning testing and rollout.
• Operate critical payment systems serving worldwide traffic and participate in on-call rotations.
• Improve performance, observability, fault tolerance, and security with automation.
• Collaborate with product and engineering partners to translate payment needs into reusable capabilities.
• Use AI-assisted tools for design, implementation, testing, and debugging with quality control.

Skills

Payment APIs

Distributed systems

Incident response

AI-assisted tools

Clear communication

Education

Bachelor's degree + 8+ years

Tools

Kotlin

Go

TypeScript

AWS

Kafka

Job description

Block, Inc. is seeking an experienced software engineer to design, build, and scale customer-facing payment APIs and the critical systems behind them.

You will lead complex projects end to end, own testing and rollout, and help shape the team’s technical direction while maintaining production systems and on-call responsibilities. You will work across Block’s payment platforms, ensure security and reliability, and leverage AI-assisted tooling to improve quality and delivery.