Software Engineer IV, Viper Engineering

Who we are looking for:

ACV Auctions is looking for a Software Engineer to join our MAX Engineering team and work on our SaaS Product, MAX Digital. The position will focus on backend development & maintenance of C#, ASP.NET features & services hosted in AWS and utilizing SQL Server.

The ideal candidate has a strong background and proven track record of architecting and designing enterprise applications in C#, ASP.NET and SQL Server, a penchant for high quality code, and a team minded approach to development.

• Develop APIs, services, background workers, and MVC web applications using C#, ASP.NET (including modern .NET), and an SQL database (SQL Server preferred; other relational databases such as PostgreSQL or MySQL are also acceptable).
• Design and build complex systems that can scale rapidly with little maintenance, with a strong focus on reliability, performance, and operational excellence.
• Design, build, and maintain Kafka-based event processing services, including consuming, deserializing, validating, persisting, and reacting to events to drive downstream workflows.
• Design and implement effective service/product interfaces, including third-party API integrations and extensible handler patterns for new integrations.
• Develop and maintain application data models, including writing and tuning complex SQL queries, optimizing indexes and performance, and designing schemas that reliably support application workflows
• Own larger, complex initiatives end-to-end—from discovery and requirements through delivery and production support—driving alignment across engineering and business stakeholders.
• Collaborate with software and production engineers to design scalable services, plan feature roll-out, and ensure high reliability and performance of our products.
• Design and develop systems across all major departments including but not limited to; data, enterprise applications, and IT.
• Lead technical design and architecture decisions across multiple systems/services, and help establish standards, patterns, and best practices.
• Modify and develop custom software patterns as needed to solve highly complex software problems, and clearly document tradeoffs and long-term maintenance implications.
• Be accountable for the overall performance of products and/or services within a defined area of focus, including diagnosing production issues and driving improvements.
• Conduct code reviews, develop high-quality documentation, and build robust test suites for your products (unit/integration testing), ensuring maintainable and well-covered code.
• Provide technical leadership through mentoring, coaching, and strong design/code review feedback, helping raise overall engineering quality.
• Develop roadmaps and prioritize technical debt to effectively plan features and work, balancing delivery with long-term platform health.
• Drive operational maturity (observability, incident response, on-call practices, reliability goals) and lead post-incident analysis with preventative action plans.
• Handle multiple competing priorities in an agile, fast-paced environment while maintaining strong engineering discipline and delivery quality.
• Perform additional duties as assigned.

• Ability to read, write, speak and understand English.
• BS degree in Computer Science or a related technical discipline or equivalent practical experience preferred
• Minimum 8 years of experience building SaaS web applications using ASP.NET, C# and JavaScript and/or Python (12+ years desirable).
• Strong experience maintaining and extending an existing codebase, adapting to pre-existing patterns and tracing the code's path of execution across services.
• Strong experience integrating 3rd-party APIs, implementing authentication & authorization and developing asynchronous data flows.
• Strong experience publishing and consuming Kafka events, including designing event contracts, building reliable event-driven workflows, and handling ordering, retries, idempotency, and failure recovery.
• Strong experience developing unit and integration-tests, and setting expectations for test strategy and coverage.
• Strong experience integrating with cloud service (AWS), specifically:…