"The demand for .NET experts who can lead backend teams is soaring as companies modernize their services. This .NET Dev Lead role in Charlotte offers a fast\u2011track contract\u2011to\u2011hire path, letting you showcase leadership on day one. If you thrive on building robust APIs and mastering multithreaded code, this opportunity is worth your attention.\n\n# Job Summary\nWe are seeking a seasoned .NET developer to lead backend API initiatives, design and implement high\u2011performance services using .NET Core, and ensure thread\u2011safe operations through advanced synchronization techniques. The role is onsite in Charlotte and starts as a contract with the intention to convert to a permanent position.\n\n# Top 3 Critical Skills Table\n| Skill | Why it's critical | Mastery Level |\n|-------|-------------------|--------------|\n| .NET Core | Foundation for building scalable backend services in the Microsoft stack | Senior |\n| Backend/API Development | Core responsibility to design, implement and maintain Web and REST APIs | Senior |\n| Multithreading & Synchronization | Ensures high\u2011performance, thread\u2011safe operations in concurrent environments | Senior |\n\n# Interview Preparation\n1. **Explain how you would design a thread\u2011safe REST API using .NET Core.**\n *What the interviewer is looking for:* Understanding of concurrency primitives (locks, async/await, concurrent collections), ability to avoid deadlocks, and knowledge of best practices for scalable API design.\n2. **Describe the differences between `IEnumerable` and `IAsyncEnumerable` and when to use each in a Web API.**\n *What the interviewer is looking for:* Insight into synchronous vs. asynchronous streaming, memory efficiency, and real\u2011world scenarios like large data sets.\n3. **How do you handle versioning and backward compatibility for REST APIs you build?**\n *What the interviewer is looking for:* Strategies such as URL versioning, media type versioning, and graceful deprecation plans.\n4. **Walk through a situation where you had to troubleshoot a multithreading bug in production. What steps did you take?**\n *What the interviewer is looking for:* Systematic debugging approach, use of tools (e.g., Visual Studio Diagnostic Tools, logging), and root\u2011cause analysis.\n5. **What performance monitoring metrics would you implement for a high\u2011traffic .NET Core API?**\n *What the interviewer is looking for:* Knowledge of latency, throughput, error rates, CPU/memory profiling, and integration with observability platforms.\n\n# Resume Optimization\n- .NET Core\n- Backend API Development\n- Multithreading\n- Synchronization\n- Web API\n- REST API\n- C#\n- Onsite\n- Contract to Hire\n- Charlotte, NC\n\n# Application Strategy\nWhen reaching out to the recruiter, send a concise email that starts with a friendly greeting, attaches your updated resume, and clearly maps your experience to the role. Highlight your leadership in backend projects, mention specific .NET Core and multithreading achievements, and reference two or three of the key skills listed above (e.g., .NET Core, API development, synchronization). End by expressing enthusiasm for the onsite opportunity in Charlotte.\n\n# Career Roadmap\n| Current Role | Typical Experience | Core Focus | Next Position |\n|--------------|-------------------|------------|---------------|\n| .NET Dev Lead | 3\u20135 years .NET, API, multithreading | Lead backend projects, mentor junior devs | Senior .NET Architect |\n| Senior .NET Architect | 5\u20138 years, system design, cloud services | Define architecture, drive technology strategy | Engineering Manager |\n| Engineering Manager | 7\u201310 years, people management, delivery | Manage multiple teams, align tech with business | Director of Engineering |"