Jo Kristian Bergum is CEO of Hornet, which builds retrieval infrastructure for AI agents. His engineering writing examines how query behavior, ranking and the interface around a search engine affect the evidence an agent can find.[2][6]
Start with Code Mode for Agentic Retrieval →
Links
Engineering articles LinkedInChief Executive Officer · Hornet
Career
Bergum’s first-person career account describes starting in enterprise search at Fast Search & Transfer and leaving in 2006. His later work includes Yahoo and the chief-scientist role documented by Vespa’s original author pages. At Hornet, he builds for agents that issue long, structured queries and may perform many searches inside one task.[3][5][4][2]
Contributions
Let code manage the evidence before it enters context
In the essay coauthored with Skip Everling, an agent writes a retrieval loop that can issue queries, deduplicate candidates, inspect fields and preserve only selected evidence. Ranking and freshness remain programmable controls inside that loop. Keeping bulky intermediate results outside the model’s conversation reduces the amount it must repeatedly read, while structured results let it decide what to inspect next. The authors emphasize that a better interface still depends on the underlying engine returning relevant documents.[6]
Hold the search engine fixed and change the harness
Bergum’s follow-up compares one tool call per model turn with a bounded Python program that can perform several retrieval steps. Both use the same model, corpus, lexical retriever and session limits. On the first one hundred BrowseComp-Plus questions, the code interface increased the share of labeled documents placed in the final curated set while reducing prompt tokens and cost. That metric measures retrieval recall, not the correctness of a final answer, and the experiment covers one model and retrieval configuration.[7]
Tools, writing & talks
Writing, research & talks
Start here
Code Mode for Agentic Retrievalhornet.devAn explanation of programmable search loops, structured results and selective context.
Read the example query-and-filter loop, then separate harness choices from ranking choices. Familiarity with search APIs helps.
Coauthor with Skip Everling[6]- The Rise and Fall of the Vector DB category: Jo Kristian Bergum (ex-Chief Scientist, Vespa)youtube.com
An interview connecting lexical search, vector retrieval and ranking for AI applications.
Interview guest[8]Original source - Code Mode vs Tool Modehornet.dev
A controlled comparison of retrieval interfaces with the engine, model and task limits held fixed.
Author[7]