Sr. C# . NET / Back End Developer

Sr. C# / .NET Engineer (Enterprise Back End)
We are looking for a Senior C# / .NET Engineer with strong architectural and engineering skills to design, build, and maintain robust back end systems that power our core business operations. This role focuses on clean, scalable service design, reliable data access, and well-structured APIs that other teams can depend on.
You will work on ---------- applications, taking ownership of back end components from design through delivery. You'll shape how our services are structured, how they perform under load, and how securely they handle data. This is a hands-on engineering role for someone who cares about doing things the right way, not just the fast way.

What we offer for this Contractor Role overview:
* Fully remote
* 40 hrs per week commitment
* Project duration - purely based on performance
* Availability to start: we are aiming early August (ideally August 1)
* We are located in Florida, United States (EST)

Key Responsibilities
Design and build back end services and REST APIs ---------- 8 and C# 12
Implement clean, maintainable architecture using Clean Architecture, CQRS, and DDD patterns
Model and manage data access with EF Core against SQL Server
Write asynchronous, performant, and secure code following established best practices
Review code and mentor other engineers on architecture and quality
Collaborate with product, front end, and DevOps teams to deliver end-to-end features
Identify and resolve performance bottlenecks, reliability issues, and security risks

Required Skills
---------- & C#
Deep expertise ---------- 8 and C# 12
Strong experience building services with ASP.NET Core
Solid command of asynchronous programming (async/await, task-based patterns)
SaaS architecture
Database design and strong SQL skills
Data & APIs
Strong experience with EF Core (queries, migrations, change tracking, performance tuning)
Proficiency with SQL Server, including query optimization and indexing
Proven ability to design clean, well-documented REST APIs
Architecture & Design
Practical experience applying Clean Architecture principles
Hands-on experience implementing CQRS
Understanding of Domain-Driven Design (DDD) patterns and when to apply them
Engineering Best Practices
Strong focus on performance, scalability, and reliability
Security-conscious mindset (input validation, authentication/authorization, secure data handling)
Commitment to writing testable, maintainable, well-structured code

Experience & Education
7+ years of ---------- development experience
Computer Science, preferable Master's Degree in Computer Science