Episode Details

Summary 
In this episode of the Data Engineering Podcast, Lucas Thelosen and Drew Gilson, co-founders of Gravity, discuss their vision for agentic analytics in the enterprise, enabled by semantic layers and broader context engineering. They share their journey from Looker and Google to building Orion, an AI analyst that combines data semantics with rich business context to deliver trustworthy and actionable insights. Lucas and Drew explain how Orion uses governed, role-specific "custom agents" to drive analysis, recommendations, and proactive preparation for meetings, while maintaining accuracy, lineage transparency, and human-in-the-loop feedback. The conversation covers evolving views on semantic layers, agent memory, retrieval, and operating across messy data, multiple warehouses, and external context like documents and weather. They emphasize the importance of trust, governance, and the path to AI coworkers that act as reliable colleagues. Lucas and Drew also share field stories from public companies where Orion has surfaced board-level issues, accelerated executive prep with last-minute research, and revealed how BI investments are actually used, highlighting a shift from static dashboards to dynamic, dialog-driven decisions. They stress the need for accessible (non-proprietary) models, managing context and technical debt over time, and focusing on business actions - not just metrics - to unlock real ROI. 


Announcements 

• Hello and welcome to the Data Engineering Podcast, the show about modern data management
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• Your host is Tobias Macey and today I'm interviewing Lucas Thelosen and Drew Gilson about the application of semantic layers to context engineering for agentic analytics

Interview
 

• Introduction
• How did you get involved in the area of data management?
• Can you start by digging into the practical elements of what is involved in the creation and maintenance of a "semantic layer"?
• How does the semantic layer relate to and differ from the physical schema of a data warehouse?
• In generative AI and agentic systems the latest term of art is "context engineering". How does a semantic layer factor into the context management for an agentic analyst?
• What are some of the ways that LLMs/agents can help to populate the semantic layer?
• What are the cases where you want to guard against hallucinations by keeping a human in the loop?
• Beyond a physical semantic layer, what are the other elements of context that you rely on for guiding the activities of your agents?
• What are some utilities that you have found helpful for bootstrapping the structural guidelines for an existing warehouse environment?
• What are the most interesting, innovative, or unexpected ways that you have seen Orion used?
• What are the most interesting, unexpected, or challenging lessons that you have learned while working on Orion?
• When is Orion the