Shopify Developer for Ongoing Maintenance & API Integrations

We are a small Canadian telecommunications company looking for a reliable Shopify developer with backend/API experience to help maintain and gradually improve an existing production platform. This is not a new Shopify store build and we are not looking to rebuild our existing systems. Most work will involve understanding existing code, troubleshooting issues, making targeted improvements, and occasionally developing new functionality. We are looking for someone we can work with on an ongoing, as-needed basis. This is not a full-time position and there are no guaranteed weekly hours. Some assignments may take only a few hours, while occasional larger tasks may require more time. Our Existing Environment: Our platform includes a combination of: Shopify Shopify Horizon theme Liquid JavaScript PHP/backend application code REST APIs Webhooks Git/source control Relational database functionality A custom customer portal Customer/account integrations Linux-based backend services You do not need previous telecommunications experience. We can explain the relevant business and provisioning logic as needed. What You May Work On: Tasks may include: Troubleshooting Shopify and Liquid issues Maintaining or modifying existing Shopify theme functionality Fixing JavaScript problems Making targeted UI or customer-account improvements Working with Shopify metafields and customer data Troubleshooting Shopify webhooks Working with Shopify and third-party APIs Working with Shopify apps Working with a backend dashboard Investigating backend application issues Reviewing database information when troubleshooting Diagnosing problems using application or server logs Making small PHP/backend changes Maintaining and improving a custom customer portal Improving error handling and recovery flows Troubleshooting integrations between Shopify, backend systems, and third-party services Adding small new features to existing systems Testing changes before deployment Most assignments will be discussed and scoped individually before work begins. Existing Codebase: A significant amount of custom functionality already exists and is currently in production. We are specifically looking for someone who is comfortable inheriting and learning another developer's code. Before making significant architectural changes, we expect the developer to discuss the proposed approach with us. We need this developer to ensure that any existing and new code is properly documented. Required Experience: Applicants should have practical development experience with: Shopify Shopify Liquid JavaScript Git/source control Working with existing/custom Shopify theme code Your Shopify experience should go beyond installing apps, configuring themes, or using the visual theme editor. We need someone who has actually worked directly with Shopify code, and Shopify app development. Backend / Integration Experience: Experience with several of the following is strongly preferred: PHP REST APIs API integrations Webhooks MySQL or other relational databases Backend development Linux/Ubuntu environments Shopify APIs GraphQL Application troubleshooting and logs You do not need to be an expert in every technology listed. We would prefer a strong Shopify developer who is comfortable working with backend integrations over someone whose experience is primarily visual design. How We Work: We are a small company, so the developer will work closely with management and employees. We value someone who can independently investigate a problem, explain what they believe is happening, and recommend a practical solution while asking questions when additional business or technical context is needed. We expect: Reliable communication while actively working on a task Clear notice when something is blocked or requires additional information Reasonable estimates before beginning larger tasks Changes to be committed to company-controlled Git repositories Brief documentation or change notes for meaningful modifications Identification of files or services changed when appropriate Testing before changes are deployed to production Advance notice of expected periods of unavailability during active work Secure handling of credentials, customer information, API keys, and confidential technical information We do not expect lengthy documentation for every small change. The goal is simply to ensure that important technical knowledge and code remain accessible to the company and can be understood by another developer if necessary. Workload and Long-Term Opportunity: This is intended to be an ongoing, low-volume development relationship for now. There may be some weeks where we have several hours of work and other periods where no development work is required. We would prefer to build a relationship with one dependable developer who becomes familiar with our systems over time rather than repeatedly hiring different freelancers for individual tasks. Individual freelancers are preferred. We are also open to developers who are newer to Upwork or earlier in their careers if they can demonstrate genuine Shopify development ability and the technical skills required for the work. As we grow, there may be an opportunity to work with us on contract. Initial Paid Task: We expect to begin with a small paid assignment. This will allow both sides to become familiar with the existing codebase and determine whether the working relationship is a good fit before we provide broader or more complex responsibilities. If the initial work goes well, we would like to continue working with the same developer on future maintenance, troubleshooting, and development tasks. When Applying: Please keep your proposal concise and answer the applicable screening questions. We are more interested in relevant experience, technical ability, communication, and reliability than in receiving a long generic proposal. Please note that all work remains the property of our company. You will be required to sign an NDA.