This role is remote, but must be in EST or CST time zones. It’s very specialized, and we need someone who has built Payment System Platforms for retail/eCommerce applications.
Candidates from large retailers such as Wal-Mart, Kroger, Sam’s Club, Home Depot, Lowe’s, etc will be highly prioritized.
Must Haves - -
10+ years of experience building payment systems
Expert level C#/ .Net 8 - must be currently hands on
Azure PaaS experience
Kafka experience (in production)
Domain Ownership
· Own the domain's architecture, technical roadmap, and key decisions
· Define domain boundaries, domain model, and shared vocabulary
· Decide which service or workflow owns each business operation
· Write ARB-ready specs and ADRs
Architecture & Design
· Design idempotent, exactly-once operations (sagas, compensation, outbox/inbox, reconciliation)
· Define API and event contracts with peer domains (OpenAPI, JSON Schema, Protobuf)
· Establish trust boundaries: who computes data, who validates it, and what consumers can rely on
Workflows & Messaging
· Build durable workflows on Temporal, including Nexus cross-domain calls
· Set versioning standards for long-running workflows (patching, build IDs, replay testing)
· Design Kafka domain events with schema governance, retries, and dead-letter queues
Payments
· Architect payment workflows across the order lifecycle: create, edit, cancel, finalize, refund
· Design multi-tender orchestration across credit/debit, EBT SNAP, and EBT WIC
· Architect processor and benefit-provider integrations: auth, capture, void, refund, reversal
· Handle gateway timeouts and unknown outcomes without double-charging or leaving ghost charges
· Ensure EBT SNAP and WIC compliance with USDA FNS and state program rules
· Lead PCI DSS scope reduction, tokenization (network tokens, DPAN), encryption, and key rotation
· Extend the domain to new tenders such as Apple Pay, Google Pay, and split tender
· Support 3P marketplace payments: multi-capture, over-capture rules, and split settlement
· Partner with Finance on reconciliation, TLOG reporting, and general-ledger accuracy
· Define payment SLOs: auth rate, capture success, refund success, and compensation failures
Reliability & Quality
· Build resilience with Polly and Temporal retry policies
· Keep payment authorization well within checkout timeout budgets across Azure and GCP
· Instrument tracing across HTTP, Kafka, and Temporal with OpenTelemetry
· Set the testing strategy: unit, contract, replay, gateway simulation, and load
Leadership
· Review production code and mentor senior engineers
· Lead feature-flagged migrations off legacy paths
· Use AI coding agents and context engineering to speed up delivery
Must-Have
· [ ] 10+ years engineering, 5+ years building payment systems
· [ ] Domain-driven design: bounded contexts, domain events, context mapping
· [ ] Expert C# / .NET 8+ and still codes
· [ ] Temporal (preferred) or similar durable workflow engine in production
· [ ] Kafka in production
· [ ] Azure PaaS: App Service, Cosmos DB, APIM, Key Vault --> Similar technology on Google Cloud Platform
· [ ] Containerization, running code in Kubernetes
· [ ] Idempotency, saga, and reconciliation patterns in production
· [ ] PCI DSS and tokenization
· [ ] OpenTelemetry or APM observability design
· [ ] Track record of aligning multiple teams on a shared architecture