Senior Payments Engineer — Acquiring & Payment Processing

Overview

Senior Payments Engineer responsible for owning and scaling Sezzle’s acquiring and payment-processing backend systems.

What you'll do

• Design and build backend services in Go that integrate with payment processors, gateways, and card networks.
• Own end-to-end money movement flows including authorization, capture, settlement, refunds, reconciliation, and disputes/chargebacks.
• Build idempotent, fault-tolerant, auditable transaction processing in a distributed architecture.
• Operate within PCI DSS scope including tokenization and secure payment data handling, plus 3DS/SCA flows where applicable.
• Instrument and monitor payment health such as authorization/decline rates, latency, and settlement accuracy.
• Use AI tooling (Claude and equivalent LLMs) as part of daily workflow; mentor engineers and help raise team standards.

What you'll need

• 8+ years of experience for this senior development role.
• 7+ years of backend or full-stack engineering experience with meaningful time in payments/fintech/money-movement systems.
• Backend engineering experience integrating with payment processors/gateways/acquiring systems.
• Experience with distributed/cloud architectures using transactional outbox and/or queuing tools like Kafka, SQS, or RabbitMQ.
• Strong Go preference, or comparable experience in Python building REST APIs.
• Hands-on use of Claude or equivalent LLM tools is required.
• Bachelor’s degree in Computer Science, Engineering, or related field.

Details

• Location: Argentina (Remote).