Senior .NET Full-Stack Engineer – Modernization & SaaS

Transit Technologies; United States; On-site; USD 140,000 - 190,000; Full time

Job summary

Transit Technologies is seeking a Senior Full Stack Developer to design, build, modernize, and support enterprise web and SaaS applications. You will work across the full software lifecycle, from backend services and APIs to web interfaces and data stores.

You will contribute to modernization efforts using both legacy .NET Framework 4.8.x technologies and modern .NET 6/8, while maintaining security, performance, and maintainability across critical systems.

Qualifications

• 6+ years of professional software development with full stack responsibilities.
• Strong experience with C#, ASP.NET Web Forms, MVC, Web API on .NET Framework 4.8.x.
• Professional experience with modern .NET (NET 6/NET 8).
• Strong SQL development with SQL Server and PostgreSQL.
• Experience designing, building, consuming, and securing RESTful APIs.
• Experience with Git-based source control, pull requests, code reviews, automated testing, and CI/CD practices.
• Working knowledge of application security, authentication, authorization, secure coding, and software quality practices.
• Ability to own features from design through production and delivery.

Responsibilities

• Design, develop, test, and maintain enterprise web and SaaS applications using C#, ASP.NET, and the Microsoft .NET ecosystem.
• Modernize existing applications while contributing to modernization using .NET 6 and .NET 8.
• Design and build scalable backend services, reusable business logic, domain components, and secure RESTful APIs.
• Optimize SQL queries, stored procedures, relational data models, and data access components.
• Collaborate with Product, QA, DevOps, Support, and other Engineering team members.
• Build automated unit, integration, and regression tests and contribute to CI/CD.
• Mentor other developers and raise technical standards across the team.

Skills

Full stack development

C#

ASP.NET

SQL

RESTful APIs

CI/CD

Security

Problem solving

Ownership

Communication

Tools

Git

GitHub

Azure DevOps

Jenkins

SonarQube

CI/CD tooling

Job description

Transit Technologies is seeking a Senior Full Stack Developer to design, build, modernize, and support enterprise web and SaaS applications. You will work across the full software lifecycle, from backend services and APIs to web interfaces and data stores.

You will contribute to modernization efforts using both legacy .NET Framework 4.8.x technologies and modern .NET 6/8, while maintaining security, performance, and maintainability across critical systems.