Full Stack Software Developer (Full-time; Hybrid)

Job Title: Full Stack Software Developer

Build practical, secure software products and components that help establish Built by Mainstreet as an internal software development capability.

Mainstreet is building an internal software development capability. This role is for a practical full stack developer who wants to build real applications, support them in production, and help shape how software gets built inside a Microsoft-based financial institution. Built by Mainstreet exists to solve internal business problems with software we can understand, improve, reuse, and support ourselves. We use modern tools, including AI-assisted development, to build software faster and more accurately. This is the first dedicated software development hire in Built by Mainstreet, so the role also helps establish practical, repeatable development standards as the capability matures.

As our Full Stack Software Developer you will build, deploy, and maintain internal software applications for Mainstreet Credit Union. You will work within a primarily Microsoft technology ecosystem. C#/.NET is our preferred application development stack, with PowerShell used extensively for scripting, automation, and environment administration. You will take applications from prototype through production for tools that support member origination, lending analysis, and staff operations. You will work with business analysts, business users who create prototypes or workflow tools, Business Intelligence, and department leaders to turn real workflows into reliable, secure products that meet our data handling and access control expectations. You will work with the Technology Architect and Systems Administrator on platform patterns, security and integration approaches, Active Directory and Microsoft Entra ID integration, and production environment configuration.

Success in your first year means you have taken ownership of at least one application end to end, including code, testing, deployment, documentation, monitoring, and support. You contribute to a working application pipeline and documented deployment process. You help mature practical standards for Git-based source control, code review, automated builds and tests, CI/CD, deployment, documentation, support, and general development practices. You respond to staff-reported issues with reliable triage and resolution cadence. You leave the codebase and operating model clearer, safer, and easier to maintain.

You will not be expected to own every infrastructure, security, database, or business domain decision independently. You will work with the Technology Architect, Systems Administrator, Business Intelligence, business analysts, and business teams to make practical decisions and build reliable software within shared standards. The Technology Architect will set the overall architecture, platform patterns, engineering standards, security and integration approaches, and technical direction. You will own implementation and day-to-day software engineering within those patterns, while contributing practical feedback as the standards evolve.

Contribute to the development and improvement of Git-based source control, code review, automated build, testing, and CI/CD practices for internal application projects.

Deploy and support applications primarily within Mainstreet’s Windows Server/IIS environment, with the ability to support cloud-hosted platforms such as Azure App Service where appropriate.

Manage application secrets and configuration using approved secure mechanisms appropriate to the hosting environment, with no secrets stored in source-controlled code or configuration. This may include environment-level configuration and cloud secret-management services such as Azure Key Vault where appropriate.

Coordinate releases through dev, test, and production environments with documented rollback steps

Monitor application health, review logs via Serilog, and respond to alerts

Apply least-privilege access controls using the authentication and authorization approach appropriate to the application and hosting environment, including Active Directory, Windows Authentication, Microsoft Entra ID, security groups, and role-based authorization.

Ensure sensitive member and financial data is encrypted in transit and at rest.

Conduct or coordinate static code scanning on every change, triage and fix flagged dependencies.

Maintain audit logs for access, data changes, and key workflow events.

Support periodic security reviews and penetration testing as required by Mainstreet’s security policy.

Triage and fix production issues raised by staff or end users.

Manage database migrations safely in production in collaboration with Business Intelligence and the Technology Architect/SQL Administrator where production data design, performance, security, or operational considerations are involved.

Keep dependencies, SDKs, and packages current.

Apply critical security patches within defined service levels.

Maintain technical documentation for deployed systems, including architecture, runbooks, and environment setup.