Senior Payments Engineer — Acquiring & Payment Processing

Overview

Senior Payments Engineer to own and scale Sezzle’s acquiring and payment-processing backend systems, integrating with processors and gateways and ensuring resilient, auditable transaction handling.

What you'll do

• Design and build backend services in Golang that integrate with payment processors, gateways, and card networks.
• Own end-to-end money-movement flows including authorization, capture, settlement, refunds, reconciliation, and chargeback/dispute handling.
• Build idempotent, fault-tolerant, auditable transaction processing using distributed architecture patterns.
• Operate within PCI DSS scope including tokenization and secure handling of payment data and 3DS/SCA flows where applicable.
• Instrument and monitor payment health such as authorization/decline rates and settlement accuracy to drive improvements.
• Use AI tooling (Claude and equivalent LLMs) as part of daily workflow for design, coding, research, testing, and documentation.
• Mentor engineers and occasionally lead small project teams to delivery.

What you'll need

• 7+ years of backend or full-stack engineering experience with meaningful time on payments, fintech, or money-movement systems.
• Strong Go experience preferred, or comparable experience building REST APIs in Python.
• Hands-on experience integrating with payment processors, gateways, or acquiring systems.
• Familiarity with payments fundamentals including authorization vs. settlement, tokenization, idempotency, reconciliation, and chargebacks/disputes.
• Experience with distributed, cloud-based architectures using patterns like transactional outboxes or queuing tools (Kafka, SQS, RabbitMQ).
• Demonstrated hands-on use of Claude or an equivalent LLM to enhance productivity, research, and communication.
• Bachelor’s degree in Computer Science, Engineering, or a related field.

Details

• Employment: Full-time.
• Work mode: Remote.