Machine Learning Engineer, Safety and Customer Care AIActive

The opportunity

At Lyft, our purpose is to serve and connect. We aim to achieve this by cultivating a work environment where all team members belong and have the opportunity to thrive.

What you'll do

  • Post-train and adapt open-source LLMs for SCC use cases using SFT, LoRA, and: preference-tuning methods (RLHF, RLAIF, RLVR).

  • Design and build AI-powered support agents and end-to-end agents for safety: case management using LangGraph or equivalent agentic frameworks.

  • Own the evaluation data flywheel, offline and online, that defines what: "good" looks like and build benchmarks for the team to hill-climb.

  • Turn interaction feedback into training data and learning signals, closing: the data flywheel that continuously improves the models.

  • Conduct literature review and build post-training framework and lifecycle.: Curate and process human and synthetic data for SFT/LoRA/RLHF/RLAIF/RLVR, and iterate on model quality for real support and safety tasks.

  • Develop, evaluate, and productionize AI agents, designing tools, state, and: control flow in LangGraph (or equivalent) and taking them through the full agent development lifecycle.

What they're looking for

  • Build and scale evaluation frameworks, golden sets, rubric-based grading,: LLM-as-judge where appropriate, and regression testing.
  • Ship models and agents into real-time production, with the monitoring and: guardrails needed to operate them safely at millions of interactions a month.
  • Apply traditional ML (classification, ranking, gradient-boosted trees) where: it's the right tool, and partner with product, ops, and data science to scope problems and define success metrics.
  • + years of industry experience in applied ML/AI, inclusive of an MS or PhD in: Computer Science, Machine Learning, Artificial Intelligence or a related technical field.