Full Stack Web Development Internship Jobs in California

Job Summary:
Applications International Corporation is a dynamic SaaS company focused on innovative software solutions in the Environmental Health Risk and Safety industry. They are seeking a Senior Full-Stack Software Developer with strong .NET MAUI expertise to design and develop customer-facing mobile applications, while also contributing to back-end services, APIs, and web development.
Responsibilities:
• Design, develop, and enhance our customer-facing cross-platform mobile app using .NET MAUI
• Implement intuitive, responsive UI/UX consistent with iOS and Android platform standards
• Identify and resolve bugs to maintain a seamless, high-quality mobile user experience
• Manage application upgrades and keep the mobile development environment current
• Ensure ongoing compliance with Google Play Store and Apple App Store policies and guidelines
• Own the mobile app release cycle including build management and store submissions
• Design and develop scalable web application components using ASP.Net, MVC, C#, and VB.Net
• Build, maintain, and enhance back-end services, modules, and application features across our platform
• Develop and maintain Queues, Loaders, and SSIS Loaders supporting API and data workflows
• Build and maintain Reports and Dashboards across various modules of our application
• Develop, maintain, and troubleshoot our public-facing RESTful APIs
• Work directly with clients to diagnose and resolve issues encountered during API integration
• Document API changes and maintain clear, up-to-date integration guides for external partners
• Implement and enhance Single Sign-On (SSO) flows and authentication integrations
• Troubleshoot and resolve SSO-related issues reported by clients and end users
• Maintain secure, standards-compliant authentication across mobile and web surfaces
• Leverage Azure cloud services for hosting, storage, and backend infrastructure
• Contribute to and maintain CI/CD pipelines following DevOps best practices
• Participate in code reviews, architectural discussions, and sprint planning
• Mentor junior developers and actively contribute to a culture of engineering excellence
• Stay current with .NET ecosystem updates, mobile platform changes, and industry best practices
Qualifications:
Required:
• Bachelor’s degree in Computer Science, Information Technology, Software Engineering, or a related field from an accredited college or university
• 5+ years of professional full-stack software development experience
• 3+ years of hands-on mobile application development using .NET MAUI or Xamarin
• 3+ years of back-end development experience using ASP.Net, MVC, C#, and/or VB.Net
• Proven experience developing, maintaining, and supporting public-facing RESTful APIs
• Demonstrated experience with SSO implementation and identity provider integrations
• Experience with SSIS, data loaders, queues, and reporting/dashboard development
• Experience with Azure cloud services and CI/CD pipeline management
• Experience across multiple areas of the Microsoft .NET stack beyond mobile (web, data, integrations)
• Deep knowledge of the Microsoft .NET ecosystem including C#, ASP.Net, MVC, VB.Net, and .NET MAUI
• Strong understanding of object-oriented programming (OOP) principles, design patterns, and software architecture
• Knowledge of RESTful API design, development, versioning, and best practices
• Familiarity with SSO protocols such as OAuth 2.0, OpenID Connect, and SAML
• Understanding of mobile UI/UX principles and iOS/Android platform-specific design guidelines
• Knowledge of secure coding practices, scalable architecture, and performance optimization
• Familiarity with SQL Server, database design fundamentals, and data pipeline management (SSIS, Queues, Loaders)
• Understanding of CI/CD workflows, DevOps practices, and Agile/Scrum methodologies
• Proficient in .NET MAUI and Xamarin for cross-platform iOS and Android mobile development
• Skilled in full-stack web development using ASP.Net, MVC, C#, and VB.Net
• Experienced in developing, consuming, and troubleshooting RESTful APIs and third-party integrations
• Hands-on experience with Azure cloud services including hosting, storage, and authentication
• Proficient with version control tools, particularly Git
• Ability to build and maintain SSIS loaders, queues, data pipelines, and reporting dashboards
• Competent with CI/CD tooling such as Azure DevOps or GitHub Actions
• Proficient with Visual Studio and the broader Microsoft development toolchain
• Versatile, adaptable and equally comfortable writing mobile UI code and architecting a backend API
• Ability to work independently and take full ownership across the entire software development lifecycle
• Strong analytical and problem-solving skills with a detail-oriented and solution-focused mindset
• Effective written and verbal communication skills, including client-facing technical support
• Ability to collaborate within a larger engineering team while managing individual deliverables
• Capacity to mentor junior developers and contribute to a culture of continuous improvement
• Proactive in keeping current with evolving technologies, platform requirements, and compliance standards
Preferred:
• Master’s degree or post-graduate coursework in a related field
• Relevant Microsoft or Azure certifications (e.g., Azure Developer Associate, Microsoft Certified: .NET Developer)
• Prior experience with App Store and Google Play submission, compliance, and release management
• Experience working directly with external clients on technical troubleshooting and integration support
Company:
Applications International Corporation is a computer software company specializing in safety management and compliance management software. Founded in 1998, the company is headquartered in San Diego, USA, with a team of 51-200 employees. The company is currently Growth Stage.