Lead Asp.NET Core 8.0 Fullstack Engineer - Remote (Australian Startup)

We are seeking an experienced Lead ASP.NET Core 8.0 Fullstack Developer to join a dynamic, Australia-based medical billing startup. This is a full-time, fully remote position for candidates located in Pakistan, working from 10 am to 7 pm PK time. The role offers a competitive tax-free salary ranging from USD 1,800 to 2,000, with a maximum notice period of 2 to 4 weeks. The ideal candidate will have extensive hands-on experience and leadership skills in ASP.NET Core 8.0, Clean Architecture, SQL Server, and modern authentication frameworks, along with familiarity in Next.js and AI integrations.

Key Responsibilities
- Lead and mentor the development team while actively designing, developing, and maintaining scalable backend services using ASP.NET Core 8.0 and Clean Architecture (Onion Architecture).
- Implement data access layers with Entity Framework Core (Code First) and manage database migrations efficiently.
- Write and optimize complex SQL Server queries, stored procedures, and database schemas to ensure high performance.
- Integrate and manage authentication and authorization using Auth0 or similar identity providers.
- Develop secure, scalable RESTful APIs following industry best practices.
- Collaborate closely with frontend developers working on Next.js and coordinate with cross-functional teams.
- Integrate external AI/ML services through APIs to enhance product capabilities (preferred).
- Work with MCP Server (Model Context Protocol) as required.
- Implement unit and integration tests to ensure code quality and reliability.
- Utilize Next.js skills and contribute to AI-related integrations within the product ecosystem.

Required Qualifications
- Minimum of 10 years of professional experience in software development.
- Strong expertise in .NET 6/7/8, with a preference for .NET Core 8.0.
- Proficient in Entity Framework Core (Code First) and managing database migrations.
- Deep knowledge of SQL Server, including T-SQL, indexing strategies, and performance tuning.
- Experience with Auth0 or similar authentication and authorization frameworks.
- Solid understanding of Clean Architecture, SOLID principles, and common design patterns.
- Proven track record in building and maintaining RESTful APIs.
- Hands-on experience with Azure services such as Service Bus and Blob Storage.
- Mandatory experience with Next.js for frontend collaboration.
- Familiarity with Git, CI/CD pipelines, and Agile development methodologies.
- Willingness to learn or experience with MCP Server.
- Strong problem-solving abilities and excellent communication skills.

Preferred Qualifications and Benefits
- Experience integrating AI/ML APIs, including familiarity with Claude, Gemini models, or other voice/AI agent technologies.
- Previous experience working in startup or product-based development environments is highly desirable.
- This role offers 100% remote work with flexible collaboration hours aligned to Pakistan time.
- Competitive tax-free salary paid in USD.
- Opportunity to work with an innovative Australian startup focused on AI-enabled medical billing products.
- Exposure to cutting-edge backend, frontend, cloud, and AI technologies in a fast-paced environment.

This position is ideal for a seasoned developer who thrives in leadership roles and enjoys working with modern fullstack technologies, cloud services, and AI integrations. If you are passionate about building scalable, secure, and intelligent applications while leading a talented team, this opportunity offers a rewarding and flexible work environment.