Livekit
Research Engineer (Reinforcement Learning)
North America, Remote. Posted 2 months ago
The role
You will build post-training for agents running over voice and text channels. This includes building environments, owning the synthetic data pipeline, and running training experiments.
What you will do
- Build the environments and verifiers our models train against
- Own the synthetic data pipeline, from generation through the quality gates
- Run training experiments end to end, and explain what moved the model
- Build the evaluations a release has to clear
- Choose and adapt open-weight base models for our tasks
- Make trained behavior hold up for voice and text agents alike
- Ship models into production and keep improving them on real usage
Required qualifications
- A strong Python engineer
- Have carried a model from raw data through to production
- Treat data as the product: coverage, diversity, leakage
- Assume a model will exploit a weak reward, and design against it
- Comfortable with GPUs and honest about their limits
- Know when to train, and when not to
- Comfortable working collaboratively in a remote environment
Nice to have
- Experience with post-training: fine-tuning, reward design, or reinforcement learning such as GRPO
- RL and fine-tuning frameworks such as TRL, verl, or OpenRLHF, or a training loop you wrote yourself
- Fast rollouts with vLLM or SGLang, multi-GPU training with FSDP
- Training tool-using or multi-turn agents
- Execution sandboxes, verifiers, eval harnesses, or tooling other engineers depend on
- Open-weight families such as Qwen or Llama, LoRA and similar
Benefits
- The opportunity to shape the brand of a fast-growing developer platform
- Collaboration with a small, senior team that deeply values craft and creativity
- Competitive salary and equity package
- Health, dental, and vision benefits
- Flexible vacation policy
About the company
LiveKit is building the infrastructure layer for the voice-driven era of computing. Their platform powers voice AI applications for companies like OpenAI, xAI, Salesforce, Coursera, and Spotify.