Software Development Engineer in Test; SDET – ML & LLM Systems

Position: Software Development Engineer in Test (SDET) – ML & LLM Systems

Make your mark at Comcast -- a Fortune 30 global media and technology company. From the connectivity and platforms we provide, to the content and experiences we create, we reach hundreds of millions of customers, viewers, and guests worldwide. Become part of our award-winning technology team that turns big ideas into cutting-edge products, platforms, and solutions that our customers love. We create space to innovate, and we recognize, reward, and invest in your ideas, while ensuring you can proudly bring your authentic self to the workplace.

Join us. You’ll do the best work of your career right here at Comcast. (In most cases, Comcast prefers to have employees on-site collaborating unless the team has been designated as virtual due to the nature of their work. If a position is listed with both office locations and virtual offerings, Comcast may be willing to consider candidates who live greater than 100 miles from the office for the remote option.)

Job Summary

This team operates at the forefront of applied machine learning, focusing on niche and highly specialized technologies such as NLP pipelines, large language model (LLM) evaluations, and ML quality frameworks. Unlike teams that primarily train or consume models, this group specializes in evaluating, validating, and measuring LLM behavior, playing a critical role in ensuring model reliability, performance, and responsible deployment.
Engineers on the team gain deep, market‑relevant expertise by continuously adapting to rapidly evolving LLM architectures, evaluation metrics, and benchmarks. The work is fast‑moving, highly technical, and offers exposure to cutting‑edge challenges that few teams encounter, making it an exciting environment for engineers who want to stay ahead of the curve in the LLM and AI evaluation space

Job Description

Key Responsibilities

• Partner with product owners, engineers, and internal stakeholders to understand product functionality, technical requirements, and quality expectations; analyze testing needs and define appropriate automation strategies.
• Design, develop, and maintain robust automated test code using software engineering best practices, ensuring reusability, reliability, and scalability.
• Develop and enhance automated test suites for functional, regression, and performance testing across machine learning models, NLP systems, and supporting backend services.
• Execute automated and manual tests as part of build validation to ensure expected behavior and maintain release quality.
• Design and implement robust test strategies and automation frameworks
  to support evolving services, workflows, and ML model testing requirements.
• Develop and maintain automated validation pipelines
  for data ingestion, data quality checks, schema validation, and anomaly detection across large-scale datasets.
• Perform model validation and verification
  , including accuracy benchmarking, regression testing, drift detection, and reproducibility checks before and after deployment.
• Investigate failing tests, diagnose root causes, and implement fixes to improve test stability and confidence.
• Review automation code contributed by peers, providing constructive feedback aligned with internal coding and quality standards.
• Coordinate QA and production build deployments in collaboration with engineering and infrastructure teams.
• Support triage and resolution of integration and production issues to ensure system reliability and rapid recovery.
• Communicate clearly and effectively with team members and leadership regarding risks, test results, priorities, and quality improvements.
• Collaborate with engineering, product, and leadership partners to continuously improve test coverage, automation effectiveness, and end‑to‑end customer experience.
• Stay current with emerging test tools, frameworks, and industry trends, and help evolve internal testing practices.
• Contribute to additional team initiatives and responsibilities as business needs evolve.
• Regular, consistent and punctual attendance. Must be able to work nights and weekends, variable schedule(s) and overtime as necessary.

Must Have

Skills:

• 2+ years of industry experience as a Software Development Engineer in Test (SDET).
• S…