Senior Software Engineer (.NET)

Location: Santa Ana, California, United States; on-site

Company

Collectors provides grading, authentication, vaulting, and sales services for collectible trading cards, autographs, comic books, coins, video games, tickets, and memorabilia through brands including PSA, PCGS, Beckett, SGC, and Card Ladder.

What you will do

• Build and operate backend services, REST APIs, data models, and internal applications supporting grading and authentication operations.
• Design event-driven, asynchronous, and high-volume systems that move operational data reliably through the grading lifecycle.
• Work across containerized .NET applications, serverless APIs, Python background jobs, managed messaging, and cloud data stores.
• Contribute to frontend development with JavaScript, TypeScript, HTML, CSS, and Vue.js to deliver end-to-end features.
• Collaborate with Product, Technology, and Operations stakeholders to turn complex requirements into extensible technical solutions.
• Support production services through troubleshooting, on-call rotation, documentation, observability improvements, and engineering best practices.

Requirements

• Must work on-site in Santa Ana, California, United States.
• Must be legally authorized to work in the United States; employment eligibility is validated through E-Verify.
• 5+ years of software engineering experience, including substantial backend development and hands-on frontend delivery.
• 3+ years of experience with C# and .NET, RESTful APIs, service integrations, automated testing, relational databases, and data modeling.
• Experience operating production cloud services, including containers, orchestration, serverless compute, API gateways, managed messaging, and data stores.
• Experience with frontend component-based applications, CI/CD, Infrastructure as Code, monitoring, observability, Agile/Scrum, and technical documentation.

Nice to have

• Experience with AWS, Python and pytest or unittest, Apache Kafka, DynamoDB, or Vue.js.
• Experience designing distributed and asynchronous systems and optimizing high-volume workflows.
• Experience partnering directly with Product, Operations, and business teams.

Culture & Benefits

• Use AI tooling, with a preference for Claude, across software design, architecture, and implementation while maintaining responsibility for delivered quality.
• Work with a large, long-lived codebase supporting a growing global collectibles operation.
• Participate in an on-call rotation for owned services.
• Video interviews require cameras to be on; some interview stages may take place by phone.

Hiring process

• Interview stages may include video and phone interviews.
• Final stages may include an on-site interview at the company’s discretion.