Worked on the livekit/agents repository to deliver core enhancements for voice agent customization, focusing on configurability, performance, and reliability. Developed an editable system prompt feature, enabling users to tailor voice agent behavior, and integrated an 'Open in Builder' shortcut to streamline configuration and testing workflows. Upgraded the default LLM and TTS models to Sonic-3 and 4.1-mini, improving inference agent accuracy and capabilities. The work centered on backend development using Python and YAML, with an emphasis on API development to accelerate iteration and deliver faster time-to-value for customers seeking more flexible and robust voice agent solutions.