Senior SDET - .NET API Automation & Azure DevOps (C#, RestSharp)

Qdex Consulting; United States; Remote; USD 120,000 - 160,000; Full time

Job summary

Qdex Consulting is seeking an experienced QA Engineer to own API test automation from code to results. You will design and build a C#/.NET API test framework using RestSharp and NUnit, and run Azure DevOps pipelines end-to-end.

You will implement design patterns, handle OAuth2 flows, pagination, and retries, and ensure failures are diagnosable. The role requires leadership in CI/CD and a focus on test reliability.

Qualifications

• 5+ years in test automation with strong hands-on C# and .NET (6+).
• Proven experience building API automation frameworks with RestSharp (or HttpClient) and NUnit/xUnit, not just adding tests to an existing one.
• Hands-on Azure DevOps: written YAML pipelines, configured agents and service connections, published test results and set up reruns.
• Clear understanding of handling flaky tests, retries and reruns in a pipeline.
• Working knowledge of Azure: Key Vault, Storage, Containers, Functions.
• Strong command of design patterns, SOLID and clean code.
• Practical use of AI tools in engineering (GitHub Copilot, Claude, OpenAI APIs).
• Clear written and spoken English; comfortable explaining results to client leadership.

Responsibilities

• Design and build API test framework in C#/.NET with RestSharp and NUnit from scratch.
• Implement design patterns (Builder, Factory, Service Object) and SOLID principles as framework grows.
• Convert high-value manual regression tests into reliable automated tests.
• Manage OAuth2, token refresh, pagination, throttling, retries and large data sets in tests.

Skills

C#/.NET

API automation

RestSharp

HttpClient

NUnit/xUnit

Azure DevOps

Design patterns/SOLID

AI tooling in engineering

English communication

Docker/Kubernetes (nice-to-have)

Tools

RestSharp

HttpClient

NUnit

xUnit

Azure DevOps

Docker

Kubernetes

Terraform/Bicep

GitHub Copilot/OpenAI APIs

Job description

Role

You'll own API test automation from the first line of code to the result on a leader's screen. That means building the framework, writing the tests, creating and running the Azure DevOps pipelines yourself, and making failures easy to diagnose and rerun. You won't wait on a DevOps team; you'll be the person who sets it up.

Responsibilities

Framework and tests

• - Design and build an API test framework in C#/.NET with RestSharp and NUnit, from scratch.
• - Apply design patterns (Builder, Factory, Service Object, Dependency Injection) and SOLID principles so the framework stays clean as it grows.
• - Turn high-value manual regression cases into reliable automated tests, starting with the areas that change most.
• - Handle real-world API behavior properly: OAuth2 and token refresh, pagination, throttling (HTTP 429), retries with backoff, and large data sets.

Pipelines you build and own (Azure DevOps)

• - Write YAML pipelines yourself: multi-stage, templated, with parameters, variable groups and environment-specific config.
• - Set up and manage build agents (Microsoft-hosted and self-hosted), service connections and secrets via Azure Key Vault.
• - Run tests on demand, on schedule or per build. Support running the full suite, a single fixture or a filtered "smart" subset chosen from what changed.
• - Run suites in parallel across agents or containers to keep run times short.
• - Publish results (TRX/JUnit) to Azure DevOps Test Plans and Test Runs, with trends visible per release.

Failures, reruns and reliability

• - Make every failure diagnosable: assertion message, stack trace, request/response logs and environment details captured per test and attached to the run.
• - Build automatic rerun of failed tests, and tell flaky tests from real defects (rerun-to-confirm, flaky-test tagging and quarantine).
• - Track flakiness and failure trends over time and fix root causes in tests, data or environments.
• - Set up notifications (Teams/email) with a clear summary of what failed and why, with no digging required.

Cloud execution

• - Containerize test suites (Docker) and run them on Azure (Container Apps Jobs, AKS or Functions) independently of the product's CI/CD when needed.
• - Manage test data and environments so runs are repeatable and isolated.

AI and reporting

• - Use AI/LLM tools to generate test cases from stories and PRs, summarize failures and produce release reports that product and engineering leaders understand at a glance.
• - Build lightweight integrations between Jira, Azure DevOps and test results for end-to-end reporting.

Preferred candidate profile

• - 5+ years in test automation with strong hands-on C# and .NET (6+).
• - Proven experience building API automation frameworks with RestSharp (or HttpClient) and NUnit/xUnit, not only adding tests to an existing one.
• - *Hands-on Azure DevOps:* you have personally written YAML pipelines, configured agents and service connections, published test results and set up reruns.
• - Clear understanding of how to handle flaky tests, retries, partial failures and reruns in a pipeline.
• - Working knowledge of Azure: Key Vault, Storage, Containers (ACR, Container Apps or AKS), Functions.
• - Strong command of design patterns, SOLID and clean code.
• - Practical use of AI tools in engineering (GitHub Copilot, Claude, OpenAI APIs or similar).
• - Clear written and spoken English; comfortable explaining results to client leadership.

Nice to have

• - Microsoft 365, Exchange, SharePoint or SaaS data-migration testing.
• - Docker and Kubernetes; Terraform or Bicep.
• - Performance testing (k6, NBomber, JMeter).
• - Jira and PractiTest integration.