C# / .NET Developer (Shopify / Middleware Focus)

Demandpdx; United States; Remote; USD 100,000 - 150,000; Full time

Job summary

Demandpdx is seeking an experienced C#/.NET Developer to expand and support a middleware layer that integrates Shopify and other systems. The role may also contribute to a mobile app backend running in a PaaS environment as the provider transitions off the account.

The ideal candidate has 4–5 years of hands-on C#/.NET experience, strong API and integration skills, and the ability to work independently in a fast-paced environment. Remote work is available across the United States.

Qualifications

• : 4–5 years of hands-on experience with C# and .NET development.
• Mastery of API design and middleware architectures.
• Experience integrating Shopify or similar ecommerce APIs is a plus.
• Strong debugging, testing, and documentation habits.
• Ability to work independently in a fast-paced client environment.

Responsibilities

• Design, develop, and maintain middleware applications using C# and .NET.
• Build and maintain integrations between Shopify and external systems.
• Use GraphQL to query and manipulate data from Shopify APIs.
• Enhance and support existing middleware services in production.
• Collaborate with cross-functional teams to define scalable solutions.
• Support and potentially transition ownership of a mobile app backend (PaaS).
• Optimize performance, scalability, and reliability of applications.
• Troubleshoot and resolve complex backend and integration issues.
• Write clean, maintainable, and well-documented code.
• Participate in code reviews and follow engineering best practices.

Skills

C#

.NET

APIs

GraphQL

Shopify APIs

Cloud / PaaS

System integration

Troubleshooting

Agile development

Communication

Tools

Shopify GraphQL Admin API

Job description

Do you enjoy building scalable backend systems that power seamless digital experiences? Do you thrive in integration-heavy environments where performance, data flow, and reliability matter? Do you like working behind the scenes to ensure platforms talk to each other efficiently and securely?

As a C# / .NET Developer, you will play a key role in expanding and supporting a client’s middleware layer that integrates Shopify and other systems. You may also contribute to a mobile app backend running in a Platform-as-a-Service (PaaS) environment, as the existing provider transitions off the account.

This role requires strong backend engineering skills, experience with APIs and integrations, and the ability to work independently in a fast-paced environment.

Responsibilities

• Design, develop, and maintain middleware applications using C# and .NET.
• Build and maintain integrations between Shopify and external systems.
• Use GraphQL to query and manipulate data from Shopify APIs.
• Enhance and support existing middleware services currently in production.
• Collaborate with cross-functional teams to define, design, and implement scalable solutions.
• Support and potentially transition ownership of a mobile app backend (PaaS-based).
• Optimize application performance, scalability, and reliability.
• Troubleshoot and resolve complex backend and integration issues.
• Write clean, maintainable, and well-documented code.
• Participate in code reviews and follow engineering best practices.

Requirements

• Experience: Minimum of 4-5 years of hands-on experience with C# and .NET development.
• Backend Development: Strong experience building APIs, services, and middleware architectures.
• Shopify (Preferred): Experience working with Shopify APIs. Direct Shopify development experience is ideal.
• GraphQL: Solid experience using GraphQL to query and manipulate data (Shopify GraphQL Admin API experience is a plus).
• Cloud / PaaS: Experience working in cloud-based or PaaS environments.
• Integration Experience: Proven experience integrating third-party systems and APIs.
• Problem-Solving: Strong analytical and troubleshooting skills with the ability to resolve complex backend issues.
• Communication: Strong written and verbal communication skills. Ability to work effectively with client stakeholders and distributed teams.
• Collaboration: Experience working in an agile development environment.

Remote Work

• This position qualifies for remote work anywhere in the United States.