Senior .NET Backend Engineer: Scalable APIs & AI-Driven

CI&T; United States; Remote; USD 120,000 - 170,000; Full time

Benefits offered by this job

Health and dental insurance

Meal and food allowance

Childcare assistance

Paternity leave

Well-being platform (Wellhub/CI&T)

Job summary

CI&T is seeking a Senior .NET Backend Developer to design, build and evolve scalable backend services using a modern .NET stack. You will work with Product, Architecture, QA and Frontend teams in a collaborative, fast-moving environment.

Responsibilities include building RESTful APIs, applying SOLID principles, implementing secure authentication, and contributing to CI/CD, observability, and code reviews. Strong English and teamwork are required.

Qualifications

• Solid experience as a backend developer with C# and .NET (8+).
• Production-grade RESTful APIs.
• Strong OO design, SOLID, Clean Architecture.

Responsibilities

• Design, build and maintain RESTful APIs and backend services with C# and .NET 8+.
• Apply Clean Architecture, SOLID and KISS principles.
• Build event-driven integrations using messaging systems (Azure Service Bus, RabbitMQ, Kafka).
• Model and optimize PostgreSQL/SQL Server with EF Core.
• Use MongoDB when needed.
• Implement OAuth2/OIDC and JWT security.
• Write unit and integration tests (xUnit, NSubstitute, Bogus).
• Contribute to CI/CD pipelines (Azure DevOps, YAML).
• Instrument services for observability (logging, metrics, tracing).
• Review code, mentor others, and collaborate with stakeholders.

Tools

MediatR

AutoMapper

Entity Framework Core

PostgreSQL

SQL Server

MongoDB

Docker

Azure DevOps

Git

Datadog

Grafana

Application Insights

ELK

Terraform

Job description

CI&T is seeking a Senior .NET Backend Developer to design, build and evolve scalable backend services using a modern .NET stack. You will work with Product, Architecture, QA and Frontend teams in a collaborative, fast-moving environment.

Responsibilities include building RESTful APIs, applying SOLID principles, implementing secure authentication, and contributing to CI/CD, observability, and code reviews. Strong English and teamwork are required.