Principal Software Engineer

About this role

### Description

About the Role

IAA is seeking a highly experienced Principal Engineer to join the Seller Applications organization. This role is responsible for setting technical direction and driving modernization for mission-critical seller experiences that enable consignors, insurance partners, and fleet sellers to list, manage, and transact vehicles through IAA’s marketplaces. You will lead the evolution of legacy systems into modern, cloud-native applications across the Azure ecosystem, raise engineering quality and reliability through strong architecture and testing practices, and serve as a trusted technical advisor to senior leaders across the Line of Business.

Key Responsibilities

• Own the technical strategy and architecture for the Seller Applications portfolio, aligning platform direction with product outcomes, operational excellence, and long-term cost strategy.
• Lead application modernization initiatives, including migration from legacy .NET Framework to modern .NET, and front-end modernization where applicable (e.g., React).
• Partner with Product, Architecture, and peer engineering leaders to define domain boundaries and decompose monoliths into well-defined services, APIs, and workflows.
• Define enterprise-grade patterns for data access and persistence (ORMs/repository patterns, schema migrations, data integrity), including modernization/migration to PostgreSQL where appropriate.
• Design for resilience and scale: establish standards for fault tolerance (timeouts, retries, idempotency), performance, capacity planning, and graceful degradation for high-volume seller workflows.
• Embed observability by default using OpenTelemetry (metrics, logs, traces) and drive measurable improvements in SLOs, incident reduction, and mean time to recovery.
• Provide strategic vision for testing practices across the portfolio, including automation strategy, quality gates, and continuous improvement of test tooling and pipelines.
• Drive the overall ...