Software Development Engineer in Test; SDET II

Software Development Engineer in Test (SDET)

Location: Los Angeles, CA

Schedule: Hybrid Schedule (M/F remote, T/W/TH in-office)

Magnite cultivates an environment of continuous growth and collaboration. Our work impacts what millions read, watch, and buy. Magnite (NASDAQ: MGNI) is the world’s largest independent sell-side advertising platform. Publishers use our technology to monetize their content across all screens and formats including CTV / streaming, online video, display, and audio. Our tech fuels billions of transactions per day.

We are looking for a Software Development Engineer in Test (SDET) to help ensure the quality, reliability, and scalability of our systems and services. In this role, you will design, build, and maintain automated testing solutions while working closely with software engineers, product managers, and other stakeholders. You’ll play a key role in improving test coverage, catching issues early, and enabling teams to ship high-quality software with confidence.

• Design, develop, and maintain automated test frameworks for multiple systems, services, and APIs
• Write reliable, maintainable automated tests (functional, integration, regression, and end-to-end)
• Collaborate with software engineers to embed testing best practices throughout the development lifecycle
• Participate in requirements and design reviews to provide a quality and testability perspective
• Execute and maintain test plans for complex, distributed systems
• Investigate, troubleshoot, and clearly document defects and test failures
• Improve CI/CD pipelines by integrating automated tests and quality gates
• Continuously evaluate and improve testing tools, frameworks, and processes

• Experience as an SDET, QA Engineer with strong automation focus, or Software Engineer with test ownership
• Strong programming skills in one or more languages (e.g., Java, Python, JavaScript, C#, or similar)
• Hands-on experience with test automation frameworks and tools (e.g., Selenium, Playwright, Cypress, REST-assured, pytest, etc.)
• Experience testing APIs, services, and distributed systems
• Solid understanding of software development fundamentals, data structures, and debugging
• Familiarity with CI/CD systems and version control (e.g., Git)
• Ability to work across multiple systems and collaborate effectively with cross-functional teams
• Strong communication skills and a proactive approach to quality

• Experience with cloud platforms (AWS, GCP, Azure)
• Experience with performance, load, or reliability testing
• Knowledge of containerization and orchestration tools (Docker, Kubernetes)
• Experience working in Agile/Scrum environments

• Comprehensive Healthcare Coverage from Day One
• Generous Time Off
• Holiday Breaks and Quarterly Wellness Days
• Equity and Employee Stock Purchase Plan
• Family-Focused Benefits and Parental Leave
• 401k Retirement Savings Plan with Employer Match
• Disability and Life Insurance
• Cell Phone Subsidy
• Fitness and Wellness Reimbursement

Magnite’s hybrid schedule includes two remote days (Monday and Friday) and three on-site days (Tuesday–Thursday). Our offices provide catered lunches, beverages, snacks, training and development, and office events. We strive to maintain a healthy work/life integration for all employees so you can bring your best every day.

• Community Service and Volunteer Events
• Company-Matched Charitable Contributions
• Wellness Coach and Mental Health Support
• Career Development Initiatives and a Career Growth Framework
• Culture and Inclusion Programs
• Bonusly Peer-to-Peer Recognition Program

The world s leading agencies and brands trust our platform to access brand-safe, high-quality ad inventory and execute billions of advertising transactions each month. Anchored in New York City, Los Angeles, Denver, London, and Sydney, Magnite has offices across North America, EMEA, LATAM, and APAC.

In CA, the base salary range for this position is: $120,000 - $130,000 in addition to an annual variable bonus based on performance and company equity (NASDAQ: MGNI).

For Los Angeles-based applicants: Qualified applications with arrest or conviction records will…