Senior Software Engineer (.NET/C#/Azure)

OVERVIEW

OnTrac is seeking a Senior Software Engineer (.NET / C# / Azure) to join a contractor program supporting a large wholesale digital-marketplace customer. The customer is rebuilding its digital auction platform and decoupling it from a legacy auction management system, standing up a new, independent, modern auction backend purpose-built for a digital-first marketplace. Phase 1 delivers the core platform: inventory management, financial transactions, and customer management. The initiative is broad in scope and spans four or more teams. This role is ideal for a hands-on senior engineer who writes production C# on .NET Core, is comfortable on Azure and Azure DevOps, and can collaborate across teams to turn business requirements into maintainable, scalable software.

ENGAGEMENT

• Expected start: ASAP

• Location: United States, fully remote

RESPONSIBILITIES

• Implement core features for the new platform, which could include inventory management, financial transactions, and customer management

• Collaborate closely with team members, other teams, and product managers to translate business requirements into technical solutions

• Develop high-quality, maintainable, and efficient C# code within an agile development environment

• Design and implement efficient data models and database interactions

• Integrate the new system with existing platforms and third-party systems

• Conduct code reviews and provide constructive feedback to peers

• Troubleshoot and debug issues, ensuring optimal performance and reliability

• Contribute to technical documentation and best practices

REQUIRED QUALIFICATIONS

• Bachelor's degree in Computer Science, Software Engineering, or a related field

• 7+ years of experience in C# development, with a strong understanding of object-oriented programming principles

• Extensive experience with .NET Core and C#

• Familiarity with front-end development using modern frameworks, specifically React

• Experience with the Microsoft Azure cloud platform, including core services and infrastructure

• Experience creating and optimizing CI/CD pipelines, specifically within Azure DevOps

• Understanding of software architecture principles and best practices, with proficiency in applying design patterns to solve technical challenges

• Proficiency in designing and developing RESTful APIs

• Solid understanding of database systems and storage (e.g., SQL Server, PostgreSQL, NoSQL) and ORM frameworks (e.g., Entity Framework)

• Demonstrated ability to write clean, testable, and efficient code

• Strong problem-solving skills and attention to detail

• Excellent communication and collaboration skills

• Experience with agentic workflows

• Comfortable working with AI and AI-assisted development tools

USEFUL QUALIFICATIONS

• Contemporary JavaScript / TypeScript (ES2015+), React Hooks, Next.js, Nx

• Experience with a message queue such as Kafka or RabbitMQ

• Experience writing GraphQL-interfaced services

• Experience working with authentication and authorization