--- title: "Teaching Coding Agents to do Spreadsheets - Nuno Campos, Witan Labs" url: https://daily.dev/posts/teaching-coding-agents-to-do-spreadsheets---nuno-campos-witan-labs-afufvo1ml source_url: https://www.youtube.com/watch?v=HEFSExa0xl0 type: video:youtube source: "AI Engineer" published: 2026-07-08T09:18:26.185Z updated: 2026-07-09T02:21:30.691Z tags: ["llm", "ai-agents"] reading_time: 19 upvotes: 1 comments: 0 language: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Teaching Coding Agents to do Spreadsheets - Nuno Campos, Witan Labs **[AI Engineer](https://daily.dev/sources/aidotengineer)** · 19 min read · 1 upvotes · 0 comments ## Summary A talk by Nuno Campos from Witan Labs covering 4 months of work improving coding agents for spreadsheet tasks, going from 50% to 92% accuracy on a financial analysis benchmark. Key findings include: replacing 15 individual tools with a Node.js REPL as the primary agent interface dramatically improved performance (50%→74% alone), persistent REPL state enabled shorter iterative scripts with more reasoning interleaved between steps, building high-fidelity formula and rendering engines created a reliable verification feedback loop, and deterministic evaluation outperforms LLM-as-judge where possible. Dead ends included multi-agent architectures with rigid discovery phases and various spreadsheet representations (SQL, XML, CSV, HTML). Generalizable lessons: give agents a real scripting language instead of many sequential tool calls, invest in domain-specific feedback loops, add domain knowledge to prompts, and always inspect traces to distinguish model errors from infrastructure bugs. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [The Era of Autonomous Coding Agents: Beyond Autocomplete](https://daily.dev/posts/the-era-of-autonomous-coding-agents-beyond-autocomplete-bvyjazl6p) · SitePoint · 0 upvotes · 0 comments --- Tags: [#llm](https://daily.dev/tags/llm), [#ai-agents](https://daily.dev/tags/ai-agents) [View this post on daily.dev](https://daily.dev/posts/teaching-coding-agents-to-do-spreadsheets---nuno-campos-witan-labs-afufvo1ml)