Senior Payments Engineer – Acquiring & Payment Processing

About the role

Sezzle is looking for a Senior Payments Engineer to own and scale the core acquiring and payment‑processing services. This backend‑focused role works closely with Product, Risk, Compliance and other engineering teams to deliver resilient money‑movement flows.

Key responsibilities

• Design and build Golang backend services that integrate with processors, gateways and card networks.
• Own end‑to‑end money‑movement flows including authorization, capture, settlement, refunds, reconciliation and chargeback handling.
• Implement idempotent, fault‑tolerant transaction processing using patterns such as transactional outbox and queues (Kafka, SQS, RabbitMQ).
• Operate within PCI DSS scope, handling tokenization, network tokens and 3DS/SCA flows.
• Instrument and monitor payment health metrics and drive continuous improvement.

Required profile

• 7+ years of backend or full‑stack engineering experience, with significant work on payments or fintech systems.
• Hands‑on experience integrating with payment processors or acquiring systems and deep understanding of payments fundamentals.
• Demonstrated use of Claude or equivalent large language model tools to enhance productivity.
• Strong ownership mindset, ability to mentor teammates and lead small project teams.

Required skills

• Golang (preferred) or Python for building REST APIs.
• Experience with Kafka, SQS or RabbitMQ and transactional outbox patterns.
• SQL databases (MySQL, PostgreSQL) and ORM usage.
• Observability tools such as Prometheus, New Relic or Datadog.
• DevOps experience with CI/CD pipelines, GitLab and containerized micro‑services on Kubernetes/AWS.