During November 2024, Bo Qu developed Time To First Token (TTFT) tracking for the deepset-ai/haystack-core-integrations repository, enhancing latency observability for prompt responses. Bo extended the Langfuse tracer in Python to capture and validate completion_start_time, ensuring robust handling of time formats and preventing noisy traces by skipping invalid entries. The implementation included comprehensive logging and addressed linting issues to maintain code quality and CI compliance. By focusing on integration development and thorough testing, Bo’s work enabled more precise latency analysis at the token level, supporting targeted performance optimizations and improving troubleshooting and SLA adherence for end-user prompts.