Senior Test Automation Engineer – UI, API & .NET

• Seattle, Washington
• Information Technology

Position: Senior Test Automation Engineer – UI, API & .NET

Company: Global Airline Manufacture

Location: Seattle, Washington, USA

Work Arrangement: Onsite x4 days a week Friday remote

Employment Type: C2C OK. Must be US Citizen or Green Card. No Visa. Contract to Hire.

Start Date: Immediate Availability

Background Check: Mandatory

Primary Technologies: Playwright, Cypress, .NET, C#, NUnit, JavaScript, REST APIs, Azure Dev Ops, Jenkins, Git Hub Actions, Git, and AI-Assisted Testing

The Senior Test Automation Engineer will design, build, implement, and maintain comprehensive automated testing solutions covering user interfaces, REST APIs, and supporting data layers. The primary performance challenge is to create reliable, maintainable automation frameworks that improve test coverage, accelerate defect identification, and support consistent software delivery.

This is a hands‑on engineering role requiring demonstrated experience developing automation frameworks from scratch rather than relying exclusively on existing test suites. The engineer will use Playwright or Cypress for UI automation, .NET/C# with NUnit for API automation, and appropriate validation techniques to test functionality and content across application layers.

The position also requires experience integrating automation into CI/CD pipelines using Azure Dev Ops, Jenkins, or Git Hub Actions. The engineer will configure test execution using dotnet, implement NUnit/TRX reporting, support environment-specific configuration and parallel execution, and maintain automated test code through disciplined Git branching, pull requests, and code reviews.

The engineer will operate in an Agile/Scrum environment and use approved AI tools to accelerate test development, improve script stability, and support debugging and analysis.

Build the automated quality‑engineering capabilities that help development teams deliver dependable software. Your work will strengthen confidence in application functionality, API behavior, and content accuracy by providing reliable automated validation across multiple technology layers.

This opportunity is well suited to an engineer who enjoys writing code, designing frameworks, troubleshooting difficult automation problems, and improving software quality through practical engineering solutions. The position offers meaningful technical ownership, visible delivery outcomes, and the opportunity to combine Playwright or Cypress, C#/NUnit, CI/CD, and AI‑assisted testing into a cohesive automation capability.

• UI Automation Engineering: Strong hands‑on experience developing and maintaining UI automation using Playwright or Cypress. Candidates should demonstrate the ability to write reliable tests, troubleshoot failures, and structure automation for long‑term maintainability.
• API Automation with .NET/C# and NUnit: Demonstrated experience writing API automation using .NET/C# with NUnit, including REST API testing, HTTP status‑code validation, response‑content validation, and debugging API failures.
• Framework Development: Proven ability to design and build automation frameworks from scratch, including reusable components, test organization, configuration management, reporting, and maintainable test architecture.
• Programming Capability: Strong practical programming skills in C# and/or JavaScript, with sufficient C# proficiency to implement the required .NET/NUnit API automation.
• End-to-End Test Strategy: Experience designing testing approaches that cover UI, API, and data layers, including the selection of appropriate validation techniques and management of cross‑layer dependencies.
• Content Validation and Test Isolation: Hands‑on experience using API‑based…