CAP Index is looking for a software developer with a strong backend foundation. You will design APIs and build containerized systems using modular monoliths and microservices. The role also includes some frontend development. You should have experience with C#, .NET, React, SQL Server, and PostgreSQL. You will make technical decisions with the team and help turn business needs into clear, maintainable software. You must be able to work both independently and with others. Location: This position is eligible for fully remote work; however, the Philadelphia area is preferred. You may need to travel up to 3 times a year. In this role, you will: * Build, maintain, and troubleshoot applications using current, supported versions of .NET and C#. * Build and improve containerized systems based on modular monolith and microservice designs. * Modernize existing systems while extending our current platform. * Design and maintain REST APIs, background services, and system integrations. * Build backend features with C#, ASP.NET Core, Entity Framework Core, and related tools. * Build frontend features with React, TypeScript, and related tools. * Design workflows that span user interfaces, APIs, databases, messages, and background processes. * Work with SQL Server and PostgreSQL data models, queries, migrations, and access controls. * Write code that can be tested at every layer. * Write unit tests, integration tests with Testcontainers, and end-to-end tests with Playwright. * Use Docker and Docker Compose to run applications and their dependencies locally. * Package and deploy applications as containers. * Trace and fix problems across the full system. * Work with the team to find the root cause of issues reported by users. * Automate repeated work and document important changes. * Build and maintain CI/CD workflows with GitHub Actions. * Use logs, health checks, metrics, and traces to find production issues. * Perform data analysis and reporting when needed. Education and Experience Requirements: * Bachelor’s Degree in Computer Science, Information Technology, Engineering, or a related field, or equivalent practical experience. * 5+ years of professional software development experience. * 5+ years of experience building applications with C# and .NET. * Experience with recent versions of .NET and a willingness to adopt new versions as the platform evolves. * Strong knowledge of C#, ASP.NET Core, and REST API design. * Experience building frontend applications with React and TypeScript. * Experience with Entity Framework Core or a similar data access framework. * Working knowledge of SQL Server and PostgreSQL. * Experience with Docker and containerized development. * Experience with xUnit, Testcontainers, Playwright, or similar testing tools. * Understanding of modular monoliths, microservices, messaging, and event-driven systems. * Experience with GitHub Actions and CI/CD is preferred. * Experience with infrastructure as code is preferred; Bicep experience is a plus. * Experience with Azure Container Apps and related Azure services is preferred; Kubernetes is a plus. * Ability to work independently, meet deadlines, and adapt when priorities change. * Ability to explain technical issues clearly to both technical and non-technical audiences. * Strong attention to detail.