Sixuan Li s a Senior Business Intelligence Engineer at Amazon, where he leads FlexLabs — the experimentation and causal inference platform serving millions of Amazon Flex delivery partners. His work focuses on the engineering and statistical infrastructure that enables large-scale companies to validate whether AI and operational interventions truly create business value, rather than appear to do so. Sean specializes in causal inference at scale, synthetic control methods, Bayesian experimentation, randomization design under network effects, and multi-agent AI systems for experiment automation. He has built production systems combining LLM-based agentic workflows with rigorous statistical estimation — bridging the gap between frontier AI capability and trustworthy enterprise deployment. ...