Senior Backend Engineer (.NET)

Key Responsibilities

• API & Service Architecture: Design, build, and maintain production-grade, secure RESTful APIs and microservices managing provider hierarchies, billing accounts, and payment lifecycle events.
• Event-Driven & Webhook Systems: Implement reliable, idempotent event consumers and webhook ingestion pipelines to process asynchronous notifications (e.g., ACH NOC events, banking state changes) with zero data loss.
• Data Migration & Modeling: Design normalized relational schemas and data transformation pipelines (DTOs, ETL backfills) to seamlessly migrate complex hierarchical records across platforms.
• Enterprise Integrations: Engineer reliable interfaces with external and internal partners—including CRM case management (Salesforce), tax identification verification (SOVOS), and banking validation services (Wells Fargo).
• State Machine & Workflow Automation: Develop scalable workflow engines and business rule decision trees governing automated verification gates (Auto-Approved, Auto-Declined, Pending Review) and CSR portal operations.
• Operational Excellence: Write comprehensive unit, integration, and contract tests, contribute to architecture reviews, and maintain clear API specifications.

Required Qualifications

• 10+ years of professional experience in backend software engineering with statically typed languages (Java, C#, Go, or TypeScript/Node.js).
• RESTful API Engineering: Demonstrated mastery in designing, versioning, and documenting production REST APIs (handling deep pagination, complex DTO mappings, and high-throughput payloads).
• Relational Databases & SQL: Strong experience in relational data modeling (PostgreSQL, MySQL, or SQL Server), complex joins, foreign-key relationships, index optimization, and data migration scripting.
• Distributed Systems & Event Architecture: Hands-on experience with message brokers/event buses (e.g., Kafka, RabbitMQ, AWS SQS/SNS) and designing idempotent consumers for webhook and asynchronous event handling.
• Enterprise Integration Patterns: Proven background integrating with third-party webhooks, REST/SOAP APIs, and handling retry strategies, circuit breakers, and distributed error handling.

Preferred Qualifications

• Prior experience in FinTech, Payment Processing, or Healthcare Payer/Provider Systems (familiarity with ACH, NACHA rules, NOC codes, TIN/NPI validation, or 835 EDI transactions).
• Experience integrating with Salesforce APIs (e.g., automated Case and Contact management).
• Familiarity with secure credential handling, financial compliance, and PII/PHI data privacy standards.