Senior Full-Stack .NET Developer – AI-Forward Engineering

About the Role

We’re looking for a senior full-stack .NET developer who treats AI tooling as a core part of their engineering practice. You’ll build and maintain a multi-service technology expense management platform built on .NET 8, working across both backend microservices and modern frontend applications. You should use AI coding assistants (Cursor, GitHub Copilot, Claude, ChatGPT, or similar) fluently, critically, and responsibly, reviewing generated code with the same rigor you’d apply to a junior developer’s PR.

What You’ll Do

• Design and implement features across a distributed .NET 8 microservice platform (REST APIs, background workers, message bus handlers)
• Build and maintain modern front-end applications using React and TypeScript
• Apply Clean Architecture and CQRS patterns to backend services
• Author and evolve EF Core database migrations in a shared schema model
• Write unit, integration, and end-to-end tests
• Use AI coding tools actively for scaffolding, refactoring, code review, and exploration while maintaining quality ownership
• Participate in code review with a focus on patterns, correctness, and maintainability
• Contribute to and uphold architectural standards and shared patterns across teams

What We’re Looking For

Must-Haves

• 5+ years of professional C# / .NET development (.NET 6+ preferred)
• Strong understanding of dependency injection, async/await patterns, and service lifetime management
• Experience with front-end frameworks (React)
• Experience with message-driven architecture (Rebus, MassTransit, NServiceBus, or similar)
• Comfort working in multi-tenant SaaS environments
• Solid SQL / EF Core skills and experience with schema migrations in production systems
• Demonstrable experience using AI coding tools as a genuine productivity multiplier, with judgment to catch what they get wrong

Strong Differentiators

• Experience with technology expense management, FinOps tooling, or cloud billing APIs (Azure/AWS/GCP)
• Background in Clean Architecture / Domain-Driven Design
• Experience with spec-driven development and code generation
• Experience writing AI-assisted code at scale and helping establish team norms around it

AI Fluency – What We Actually Mean

• Use AI tools to accelerate first drafts of handlers, tests, UI components, and migrations
• Critically review AI-generated code against architectural patterns and push back when it deviates
• Leverage AI for codebase exploration, refactoring proposals, frontend+backend scaffolding, and documentation
• Stay current with evolving AI tooling and bring useful techniques back to the team

Tech Stack

• .NET 8, C#, ASP.NET Core
• React / TypeScript / Blazor (front-end)
• Message bus (Rebus, MassTransit, or similar), EF Core (SQL Server)
• Azure (App Services, Service Bus, Application Insights)
• xUnit, FluentAssertions, FakeItEasy
• Cursor / GitHub Copilot (AI-assisted development)
• Git, Azure DevOps, PowerShell

What Good Looks Like in This Role

• You reach for AI to eliminate boilerplate and then own what it produces
• You contribute well-structured backend handlers and clean, testable frontend components
• You notice when a handler or UI module is growing unwieldy and extract without being asked
• You read the patterns guide before introducing something new
• You write backend and frontend tests that describe intent, not just coverage
• You treat shared database migrations as carefully as production deployments

Calero is an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to race, religion, color, national origin, sexual orientation, gender identity, age, protected veteran status, or status as a qualified individual with a disability. 

 The salary range for this position starts at $120,000. It is important to Calero that potential candidates for this position understand that compensation depends on numerous factors including the geographic location where the role will be performed, skills required, experience, complexity, travel, and market rate. Calero aims to reward performance and attract top talent with competitive, fair pay and benefits. Please note that the top of the salary range represents exceptional, and/or senior-level positions, that meets all required qualifications. Actual offers take candidate’s knowledge, skills, abilities, and experience into account. Base Pay is just one component of the total compensation package for employees. Other rewards vary by position and location.