Senior Full-Stack Engineer (C#/.NET & React)

Cognativ; United States; Remote; USD 140,000 - 200,000; Full time

Job summary

Cognativ is seeking a senior full-stack engineer to design robust C#/.NET back-ends and modern React/Next.js UIs. You will own domain modeling, API design, and asynchronous processing within an Azure-based, modular monolith.

You'll contribute across the stack, ensure testability and maintainability, and mentor other engineers while delivering customer- and operations-facing applications.

Qualifications

• 8+ years of professional software development experience.
• Strong backend design in C#/.NET (ASP.NET Core).
• 4+ years building production front-end apps with React/Next.js.
• Experience with relational DBs and ORMs (EF Core).
• Proficient TypeScript and monorepo package usage.
• Cloud infra experience (Azure preferred).
• Experience with OAuth2/OIDC authentication.
• Solid automated testing discipline (unit/integration/contract).
• Full-stack development across API, UI, and data models.
• Collaborate on API contracts and shared TS types.

Responsibilities

• Design and build clean, testable backend architecture (Clean Architecture).
• Develop and maintain multiple Next.js/React apps for internal and external users.
• Build and maintain asynchronous background processing services and message-queue coordination.
• Model relational data and implement data access with EF Core/PostgreSQL.
• Collaborate on API contracts and shared TypeScript types for front-end teams.
• Mentor engineers and participate in code reviews and design discussions.

Skills

C# / .NET

ASP.NET Core

React

Next.js

TypeScript

Azure

OAuth2 / OIDC

CI/CD

Unit & integration testing

Domain-driven design

Education

Bachelor's degree in Computer Science

Tools

EF Core

PostgreSQL

SQL

Azure DevOps

Message Queues

Blob Storage

Job description

Cognativ is seeking a senior full-stack engineer to design robust C#/.NET back-ends and modern React/Next.js UIs. You will own domain modeling, API design, and asynchronous processing within an Azure-based, modular monolith.

You'll contribute across the stack, ensure testability and maintainability, and mentor other engineers while delivering customer- and operations-facing applications.