Senior Software Engineer - .NET

About the role

About Us

At Auctane, we are united by a passion to help businesses deliver — whatever their size, wherever they are, and however they operate. We make it possible for businesses to meet the ever-changing requirements of their industry and customer expectations. Auctane products enable hundreds of thousands of businesses to annually mail and ship billions of items — over $200 billion worth — to recipients around the globe.

The Auctane family of mailing and shipping software products includes ShipStation, Stamps.com, ShipStation API, Metapack, GlobalPost, and Packlink. Our partners include Amazon, UPS, USPS, eBay, BigCommerce, Shopify, WooCommerce, and Walmart.

Our values

Win as One. Delight Customers. Deliver Great Outcomes.

About The Role

We're seeking an experienced Senior Software Engineer - .NET to join our engineering team. In this role, you'll architect and build scalable backend systems that power our applications, working across our modern tech stack to deliver robust, high-performance solutions. This position is focused on the ShipStation API brand.

This position is hybrid (3 days per week in office - Tuesday through Thursday) and is located in Austin, TX.

What will you be doing?

You'll design and implement backend services and APIs that serve millions of requests, working closely with frontend teams to create seamless user experiences. Your work will involve building new features, optimizing existing systems, and making key architectural decisions that shape our platform's future. You'll mentor other engineers, participate in code reviews, and help establish best practices across the team.

System Architecture & Design: Architect, build, and maintain scalable, robust backend services and microservices using C# and .NET.

API Development: Create and consume secure REST APIs for seamless communication between backend services and front-end/mobile applications.

Database Management: Design, query, and optimize relational databases (both SQL and NoSQL).

Code Quality & Best Practices: Conduct rigorous code reviews, enforce engineering standards, and write clean, maintainable, production-ready code.

Mentorship: Provide technical guidance, support, and mentorship to mid-level and junior developers.

DevOps & Cloud: Collaborate with the infrastructure team to configure CI/CD pipelines, deploy applications to the cloud (AWS), and maintain different environments.

Testing: Develop and maintain unit tests and integration tests to ensure application reliability.

What are we looking for?

Required Technologies:

.NET - Strong proficiency in .NET, including ASP.NET Core, Entity Framework Core, and building RESTful APIs. Experience with C# design patterns and async programming

AWS - Hands-on experience deploying and managing services on AWS, including EC2, Lambda, RDS, S3, CloudFront, SQS and API Gateway. Familiarity with infrastructure as code (Terraform, CloudFormation or CDK)

React - Some experience with front-end JavaScript component libraries such as React.

Additional Skills:

Background in DevOps practice

Strong understanding of database design (both SQL and NoSQL)

Experience with containerization (Docker) and orchestration

Knowledge of authentication/authorization patterns (OAuth, JWT)

Understanding of microservices architecture and distributed systems

Proficiency with Git and CI/CD pipelines

Experience with monitoring, logging, and performance optimization

Nice to Have

TypeScript

Experience with event-driven architectures and message queues

Knowledge of caching strategies (Redis, CDN)

Background in DevOps practices

We embrace AI-assisted development and expect our engineers to leverage these tools effectively. You should be comfortable using AI coding assistants (like GitHub Copilot, Claude, or similar tools) to accelerate development while maintaining code quality and security standards. Experience integrating AI capabilities into applications (OpenAI API, Claude API, or AWS Bedrock) is a plus. We value engineers who can critically evaluate AI-generated code, understand when to use these tools, and when human expertise is essential.

Qualifications

4+ years of backend development experience

Bachelor’s Degree in Computer Science

Proven track record of building and scaling production applications

Strong problem-solving abilities and attention to detail

Experience mentoring junior developers

Demonstrated ability to use AI tools responsibly to enhance productivity

What do we offer?

🏠 We are a hybrid company. All team members at Auctane in Austin come into the office Tuesdays, Wednesdays and Thursdays.

🛬Take the reins of your time off with our Flex Time Off policy – because work-life balance should always be in your hands!

🌅 We offer 12 paid holidays for all of our US employees!

💰401k employer matching program – because your future deserves a friendly boost!

⭐️We conduct annual merit reviews to recognize and reward your hard work and achievements.

🏟️ Company events, we work hard, play hard! We do our best every day, even at our regular team-building events.

🏢 Attractive office space in the heart of central Austin, Texas (free drinks, snacks…).

🍽Indulge in weekly catered lunches at our office – a delicious perk to fuel your work.

🏐 Health and Wellness: The well-being of our team is super important to us. Choose from different options that include medical, dental, and vision plans.

🏋🏾‍♀️Fitness center in the office with Tonal Mirrors, Pelotons, free weights, etc.

🧠Employee Assistance Program. We offer up to 8 free mental health sessions.

💪🏽We offer gym discounts to help you stay fit and healthy!

📚We offer education reimbursement to all employees, ensuring that you can pursue your educational goals while excelling in your career with us. Invest in your future and let us support your growth every step of the way.

🔗 Employee Referral Program! We reward employees helping us find top talent!

💜 An inclusive, casual and upbeat work environment. The personality and opinions of each of our team members are important and valid; we aim to offer all employees a safe environment where they can be themselves and thrive.

Additional Position Duties: (The following is a list of what all employees, except those with medical accommodation, may be regularly required to do.)

Sit for prolonged periods of time

Utilize wrist and hands for a prolonged period of time

Walk short distances

Stand for short periods

Speaking and conversing with others

Lift up to 25lbs without assistance up to chest height

Equal Opportunity Employer/Veterans/Disabled

If you are based in California, we encourage you to read this important information about the ShipStation Privacy Policy for California residents linked here.