Senior .NET Backend Engineer for AI-Driven, Scalable APIs

CI&T; United States; Remote; USD 110,000 - 190,000; Full time

Benefits offered by this job

Health and dental insurance

Meal and food allowance

Childcare assistance

Extended paternity leave

Wellness partnerships

Job summary

United States Digital Space LLC is seeking a Senior .NET Backend Developer to join one of our delivery teams. You will design, build and evolve scalable backend services using a modern .NET stack, collaborating with Product, Architecture, QA and Frontend teams in a fast-paced, multicultural environment.

You will implement secure authentication, write automated tests, contribute to CI/CD pipelines and mentor junior developers to ensure quality, security and performance across services.

Qualifications

• Solid experience as a backend developer with C# and .NET, production-grade RESTful APIs.
• Strong knowledge of OO design, SOLID, patterns and Clean Architecture.
• Hands-on experience with MediatR, AutoMapper and EF Core.
• Experience with PostgreSQL/SQL Server, data modelling and query optimization.
• Experience with distributed systems and messaging (Azure Service Bus, RabbitMQ, Kafka).
• Experience using AI tools in development and AI-assisted code generation/refactoring.
• Experience with automated testing (unit/integration).
• Working knowledge of Docker and Docker Compose.
• Familiarity with observability tools (Datadog, Grafana, App Insights).
• Experience with Git, CI/CD and Azure DevOps.

Responsibilities

• Design, develop and maintain RESTful APIs and backend services using C# and .NET 8+.
• Apply Clean Architecture, SOLID and KISS to keep code modular and reusable.
• Build event-driven integrations using messaging platforms (Azure Service Bus, RabbitMQ, Kafka).
• Model and optimize relational databases (PostgreSQL, SQL Server) with EF Core.
• Work with MongoDB when needed.
• Implement secure authentication/authorization (OAuth2/OIDC, JWT).
• Write and maintain unit and integration tests (xUnit, NSubstitute, Bogus).
• Contribute to CI/CD pipelines (Azure DevOps, YAML) and GitFlow workflows.
• Instrument services for observability (logging, metrics, tracing).
• Review code for quality, security and performance; mentor teammates.
• Collaborate with stakeholders to translate requirements into pragmatic solutions.

Skills

C#

.NET 8+

REST APIs

SOLID principles

Clean Architecture

MediatR

AutoMapper

Entity Framework Core

Azure Service Bus

RabbitMQ

Kafka

Docker

Tools

Azure DevOps

Git

Docker Compose

Datadog

Grafana

Application Insights

Job description

United States Digital Space LLC is seeking a Senior .NET Backend Developer to join one of our delivery teams. You will design, build and evolve scalable backend services using a modern .NET stack, collaborating with Product, Architecture, QA and Frontend teams in a fast-paced, multicultural environment.

You will implement secure authentication, write automated tests, contribute to CI/CD pipelines and mentor junior developers to ensure quality, security and performance across services.