Backend Engineer (.NET) – Mid & Senior Level en Crossbridge

Backend Engineer (.NET) – Mid & Senior Level

100% Remote | Contractor | Paid in USD | Long-Term Engagement

We are looking for Mid-Level and Senior Backend Engineers with strong experience in the Microsoft ecosystem and a solid foundation in software design principles.

This opportunity is ideal for engineers who enjoy building secure, scalable, and maintainable backend systems using modern .NET technologies. Depending on your experience level, you may focus on hands-on development or take ownership of architectural decisions and technical leadership.

What You’ll Do

• Design, develop, and maintain scalable backend services using .NET Framework (4.8+), .NET Core (3.x), and .NET 8.x with C#

• Build, optimize, and modernize RESTful APIs

• Refactor and enhance existing codebases to improve performance and reliability

• Maintain and modernize legacy systems (including WCF-based services transitioning to ASP.NET Core)

• Design and manage data access layers using EF Core or similar ORMs

• Write efficient and optimized SQL queries across relational databases

• Implement secure authentication and authorization mechanisms (OAuth 2.0, JWT, claims-based security, SSO, Active Directory)

• Collaborate with Product, QA, DevOps, and Frontend teams

• Participate in Agile ceremonies (Sprint Planning, Standups, Retrospectives)

For Senior-Level Engineers (Additional Responsibilities)

• Lead backend architecture and technical design decisions

• Define and enforce best practices in object-oriented design and clean architecture

• Mentor mid-level developers and perform advanced code reviews

• Troubleshoot complex production issues and lead root cause analysis

• Influence long-term technical direction and modernization strategies

Requirements Mid-Level

• 6+ years of professional software development experience

• 4+ years of backend development using .NET and C#

• Experience developing and maintaining RESTful APIs

• Working knowledge of EF Core or similar ORM

• Intermediate SQL skills

• Experience with ASP.NET Core or WCF

• Understanding of authentication & authorization mechanisms

• Experience with Git and Agile methodologies

• Advanced English (daily communication with US-based teams)

Senior-Level

• 8+ years of professional software development experience

• 6+ years of backend development using .NET and C#

• Strong experience with RESTful APIs and backend architecture

• Deep understanding of OOP, clean architecture, and secure system design

• Experience implementing OAuth 2.0, JWT, Active Directory, SSO, federation services

• Experience modernizing legacy systems

• Strong problem-solving skills and technical leadership experience

• Advanced English (daily communication with US-based teams)

Tech Stack

• .NET Framework 4.8+

• .NET Core (3.x) / .NET 8.x

• C#

• ASP.NET Core

• WCF

• EF Core

• SQL Server / MySQL / Oracle / PostgreSQL

• OAuth 2.0 / JWT / Active Directory

• Git / GitLab / SVN

• Agile (Scrum/Kanban)

What We Offer

• 100% remote position

• Long-term contractor engagement

• Compensation paid in USD

• Opportunity to work on enterprise-level backend systems

• Exposure to architectural discussions and modernization initiatives

• Collaborative, high-impact engineering environment

If you are a backend engineer looking for a stable, long-term remote opportunity where you can grow technically and work with enterprise-grade systems, we would love to connect with you.