Senior FullStack Engineer

**This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Senior FullStack Engineer based in Canada.** Join a remote-first engineering team building reliable, modern business systems and payment solutions for growing companies. As a Senior FullStack Engineer, you will develop and ship features for a prepaid card and payments platform, combining hands-on software engineering with AI-assisted development. You will use tools such as Claude Code to accelerate implementation while applying strong engineering judgment to review code, debug complex issues, and validate changes through rigorous testing. Working across backend services, frontend applications, databases, cloud infrastructure, and payment integrations, you will help ensure that financial transactions and sensitive customer data remain secure and reliable. The role emphasizes problem-solving, accountability, and delivering production-ready software rather than simply generating code. You will also benefit from dedicated learning time, paid certifications, and the flexibility of a distributed working environment. ### Accountabilities: As a Senior FullStack Engineer, you will take ownership of delivering reliable software changes across a complex payments ecosystem. You will combine AI-assisted implementation with careful code review, comprehensive testing, and a strong focus on financial accuracy, data security, and the end-user experience. - **AI-Assisted Development:** Use Claude Code as your primary development tool to plan changes, direct AI agents, review generated code, refine implementations, and deliver production-ready features. - **Code Review and Quality Assurance:** Identify incorrect, incomplete, or unsafe AI-generated code, independently assess its quality, and ensure that all changes meet engineering standards. - **Testing and Validation:** Write targeted tests that demonstrate the original issue and verify the fix, while ensuring existing user journeys continue to work correctly. - **Full-Stack Engineering:** Build and maintain backend services using C# and .NET 8–10, Azure Functions, APIs, Entity Framework Core, and Dapper. - **Frontend Development:** Develop and maintain web and mobile applications using React, React Native, TypeScript, JavaScript, and Angular. - **Database and Data Management:** Work with MySQL, SQL Server, Cosmos DB, Azure Cache for Redis, queues, and related data systems to maintain reliable data processing and access. - **API and Integration Development:** Build, troubleshoot, and maintain APIs and integrations with card processors, payment and payout partners, identity verification providers, and messaging services. - **Cloud Infrastructure and Delivery:** Work with Azure Functions, Azure App Services, Key Vault, Application Insights, Terraform, Bitbucket Pipelines, and private NuGet packages hosted through Azure Artifacts. - **Payment Reliability and Security:** Investigate edge cases involving transaction timeouts, duplicate debits, refunds, inconsistent application and server behavior, and unauthorized access to customer or card data. - **Cross-Layer Debugging:** Trace issues across frontend applications, backend services, APIs, databases, and external integrations to identify root causes and implement dependable solutions. - **Production Ownership:** Deliver tested changes, communicate progress clearly, and take responsibility for the quality, reliability, and real-world impact of your work. **Requirements:** The ideal candidate is an experienced full-stack engineer who has already incorporated AI coding agents into real-world software delivery. You should be able to understand unfamiliar codebases, independently debug problems across the application stack, and recognize risks that automated tools may overlook. Strong attention to detail is essential, particularly when working with financial transactions and sensitive customer information. - **Professional Experience:** Approximately 4–6 years of full-stack engineering experience, with strong hands-on development and debugging skills. - **AI Development Tools:** Demonstrated experience using Claude Code, Cursor, GitHub Copilot, Codex, or similar AI coding tools to ship real software. Claude Code is the primary development tool for this role. - **Backend Technologies:** Strong proficiency in C# and .NET 8–10, with experience in Azure Functions using the isolated worker model, legacy layered APIs, Entity Framework Core, and Dapper. - **Frontend Technologies:** Experience with React for web applications, React Native and TypeScript for iOS and Android, and Angular with TypeScript for partner portals. - **Testing and JavaScript Tooling:** Familiarity with Node.js and Jest, along with the ability to create meaningful automated tests and validate end-to-end user workflows. - **Databases and Messaging:** Practical experience with MySQL, SQL Server, Cosmos DB, Azure Cache for Redis, and queue-based processing. - **Cloud and DevOps:** Familiarity with Azure Functions, Azure App Services, Key Vault, Application Insights, Terraform, Bitbucket Pipelines, and Azure Artifacts for private NuGet packages. - **API and Third-Party Integrations:** Experience developing and debugging APIs and integrating external payment, payout, card-processing, identity verification, SMS, email, and push notification services. - **Code Review and Debugging:** Ability to evaluate code written by others or generated by AI, identify defects independently, and investigate problems across frontend and backend boundaries. - **Security and Data Integrity:** A careful, security-conscious approach to financial transactions, customer data, authorization, error handling, and failure scenarios. - **Problem-Solving and Ownership:** Strong analytical skills, sound technical judgment, attention to detail, and the ability to take responsibility for delivering dependable outcomes. - **Preferred Qualifications:** Experience with payments or card issuing, PCI awareness, and security review processes is an advantage. **Benefits:** - Fully remote work arrangement, with the flexibility to work from anywhere. - Flexible scheduling, allowing you to organize your workday around personal commitments while meeting delivery expectations. - Time off when needed. - A dedicated work laptop that can be configured to suit your preferences within security guidelines. - Opportunities to meet and collaborate with teammates in person during designated team gatherings. - Dedicated learning time during working hours. - Paid professional certifications to support continued technical development. - Opportunities to deepen your expertise in AI-assisted engineering, cloud infrastructure, full-stack development, and payment systems. - Salary, healthcare coverage, retirement benefits, and other specific compensation details are not provided in the job description.