.NET API Developer

NET API DeveloperPennant is seeking an experienced contract software developer to design, enhance, and support web-based applications built with C# and the.NET framework. This role is well suited to an independent, delivery-focused professional who can quickly understand existing systems, identify technical issues, and contribute meaningful improvements with limited onboarding or day-to-day supervision.Primary ResponsibilitiesThe selected contractor will:Develop, maintain, test, and troubleshoot web applications and RESTful APIs using C#,.NET, ASP.NET Core, and related Microsoft technologies.Analyze existing application code, technical documentation, database objects, and integration points to implement enhancements, resolve defects, and improve reliability.Produce clean, secure, readable, and maintainable code that follows established development standards, architecture patterns, and source-control practices.Build and support API endpoints, including request validation, authentication and authorization, error handling, logging, versioning, and integration with internal or external services.Work independently to investigate complex technical issues, determine root causes, propose practical solutions, and communicate progress and risks to project stakeholders.Participate in code reviews, technical design discussions, testing, deployment planning, and change-management activities.Create and maintain technical documentation for application components, APIs, configuration settings, deployment procedures, and operational support needs.Database and Data ResponsibilitiesWhile the primary emphasis is on .NET application and API development, the contractor should also be capable of supporting the SQL Server data layer. Responsibilities may include:Developing and maintaining SQL Server database objects, including tables, views, stored procedures, functions, and indexes.Writing and optimizing T-SQL queries used by web applications, APIs, reporting processes, and data integrations.Troubleshooting data-quality, performance, concurrency, and application-to-database connectivity issues.Supporting database schema changes and data migrations in coordination with application releases.Applying secure data-access practices, including parameterized queries, least-privilege access, protection of sensitive data, and appropriate auditing.Azure Hosting and Deployment ResponsibilitiesThe contractor should be comfortable configuring and supporting applications hosted in Microsoft Azure, including the deployment and operational needs of cloud-based web applications. Relevant experience may include:Configuring and supporting Azure App Service, Azure Functions, API Management, Azure SQL Database, storage services, and related hosting components.Managing application configuration through environment-specific settings, managed identities, Azure Key Vault, and secure secrets management practices.Supporting CI/CD pipelines, preferably through Azure DevOps, GitHub Actions, or comparable tooling.Troubleshooting application availability, authentication, networking, logging, monitoring, and performance issues in Azure environments.Reviewing hosting configurations for security, scalability, resiliency, and cost-conscious operation.Required QualificationsCandidates should demonstrate:Strong hands-on experience developing web applications and APIs using C#,.NET, ASP.NET Core, and related Microsoft development tools.Experience working with RESTful API design, JSON, methods and status codes, authentication and authorization patterns, and third-party system integrations.Strong SQL Server and T-SQL skills, including database development, query optimization, and troubleshooting.Experience with Git-based source control, code review processes, issue tracking, and structured software-development practices.Familiarity with Azure-hosted application environments and cloud configuration management.The ability to work effectively with minimal supervision, manage assigned priorities, and provide clear, timely communication to both technical and nontechnical stakeholders.Strong analytical and problem-solving skills, particularly when working with unfamiliar codebases or legacy applications.Preferred QualificationsPreference may be given to candidates with experience in:Azure DevOps pipelines, release management, and infrastructure-as-code practices.Entity Framework Core, Dapper, or other .NET data-access frameworks.Microsoft Entra ID, OAuth 2.0, OpenID Connect, managed identities, and role-based access control.Azure Key Vault, Application Insights, Azure Monitor, API Management, and Azure SQL.Legacy.NET Framework applications as well as modern.NET / ASP.NET Core solutions.Secure software-development practices, vulnerability remediation, dependency management, and OWASP-aligned application security.