Senior Application Developer – Custom eCommerce

Senior Application Developer – Custom eCommerce Location: McKinney, TX – Onsite Position Type: C2H Job Overview We are looking for a Senior Application Developer with strong hands-on experience building custom B2B and B2C eCommerce applications using modern web technologies such as React.js and Next.js. This is a hands-on senior engineering role responsible for designing, developing, integrating, and supporting scalable, high-performance, end-to-end eCommerce solutions. The ideal candidate should have a strong background in custom eCommerce application development, modern frontend architectures, API-driven applications, backend integrations, and cloud platforms. The candidate will work closely with Product, UX, Mobile, Integration, Platform, and other cross-functional teams to transform business requirements into secure, scalable, performant digital experiences. Key Responsibilities Custom eCommerce Application Development Design, develop, and enhance custom B2B and B2C eCommerce applications.Build modern, scalable, high-performance web applications using React.js, Next.js, JavaScript/TypeScript, and related technologies.Develop reusable frontend components, application modules, and shared UI capabilities.Translate business and functional requirements into technical designs and production-ready implementations.Develop end-to-end features across frontend, backend services, APIs, integrations, and cloud environments.Troubleshoot, optimize, and enhance existing eCommerce applications.Frontend Architecture & UI Engineering Design and implement modern, modular UI architectures.Work with architectural patterns such as:Micro-Frontend ArchitectureMicroAppsWeb ComponentsAtomic DesignServer-Driven UIBackend-for-Frontend (BFF)Build reusable component libraries and scalable design-system capabilities.Ensure responsive, accessible, performant, and maintainable user experiences.API & Integration Development Design, develop, and integrate RESTful APIs and/or GraphQL services.Build API-driven application architectures supporting eCommerce workflows.Integrate frontend applications with backend services, third-party platforms, and enterprise systems.Collaborate with integration and platform teams to deliver cohesive end-to-end solutions.eCommerce Engineering Apply strong understanding of core eCommerce concepts and workflows.Develop solutions supporting B2B and B2C customer journeys.Work across capabilities such as product, catalog, pricing, customer, cart, checkout, order, and related eCommerce functionality.Contribute to scalable and composable eCommerce architectures.Cloud & DevOps Develop and deploy applications using cloud platforms such as Azure or AWS.Work with CI/CD pipelines and modern DevOps practices.Use Git/Bitbucket and established source-control and development workflows.Support application deployment, troubleshooting, and production releases.Performance, Security & Quality Identify and resolve application performance issues.Apply web application security best practices.Conduct code reviews and promote clean, maintainable, and reusable code.Develop and maintain appropriate unit/integration testing.Ensure solutions meet scalability, reliability, security, and performance requirements.Collaboration & Technical Leadership Collaborate with Product Owners, UX, Mobile, Integration, Platform, and other engineering teams.Participate in Agile development processes.Mentor junior and mid-level developers.Promote engineering best practices, reusable patterns, coding standards, and continuous improvement.Required Qualifications Bachelor's degree in Computer Science, Engineering, or a related field.6+ years of application development experience, preferably with B2B and/or B2C eCommerce platforms.Strong hands-on experience building custom eCommerce applications.Strong hands-on experience with React.js and Next.js.Strong JavaScript/TypeScript development experience.Experience designing and developing modular, reusable UI architectures.Experience building API-driven applications.Hands-on experience developing and integrating RESTful APIs and/or GraphQL.Strong understanding of eCommerce concepts, customer journeys, and transactional workflows.Experience with Azure and/or AWS.Experience with CI/CD, DevOps practices, and Git/Bitbucket.Strong understanding of web application security and performance optimization.Strong communication, collaboration, troubleshooting, and problem-solving skills.Experience working in an Agile environment.Preferred Qualifications Experience with PHP and Adobe Commerce/Magento.Experience with micro-frontends, MicroApps, Web Components, design systems, or shared component libraries.Experience with composable commerce and MACH architecture.Experience with Server-Driven UI and/or Backend-for-Frontend (BFF) architecture.Experience with analytics platforms such as Google Analytics or Adobe Analytics.Experience with observability and monitoring tools such as New Relic or Azure Monitor.