Sarah Buchner built Trunk Tools from a career that started in carpentry

Sarah Buchner Trunk Tools is a founder story rooted in construction sites rather than a conventional software career. Buchner began working as a carpenter at 12 in Austria, then used experience across the building industry to create an AI company aimed at a costly daily problem: finding and using the right project information.

For investors watching industry-specific AI, the company’s origin helps explain its pitch. Trunk Tools is trying to make drawings, specifications, schedules and other job-site records easier for construction teams to search, connect and act on. The company announced a $40 million Series B in July 2025, bringing its total funding to $70 million.

How did Sarah Buchner go from carpenter to Trunk Tools founder?

Buchner grew up in a low-income household in a small Austrian village, according to Crunchbase News and a 2024 TechCrunch report republished by Yahoo Finance. Her father was a carpenter, and she began joining him on job sites as a child when the family needed additional income.

Her construction career continued for more than a decade. Buchner told TechCrunch that she moved from carpentry to the general-contractor side, progressing through superintendent, project manager and group leader roles. Crunchbase News reported that she later managed large European projects as a general contractor.

A fatality at a site she was running became a turning point, Buchner told Crunchbase News. She subsequently pursued a health-and-safety app for construction workers, a venture separate from and earlier than Trunk Tools. That work introduced her to software and led to doctoral research focused on construction data science and early AI, according to the publication.

Her research identified the central issue Trunk Tools would target: project information may exist, but it can be scattered among systems and buried in unstructured documents. Unstructured information is data that does not arrive in a consistent, easily searchable format, such as a mix of PDFs, drawings, spreadsheets and text-heavy specifications.

What does Trunk Tools do for construction teams?

Trunk Tools says its platform organizes project materials, including drawings, requests for information, schedules and submittals, then lets teams ask questions in plain language. It also offers AI agents, software designed to carry out parts of a workflow, such as reviewing documents for inconsistencies or linking project records to a schedule. Those are company descriptions of the product rather than independently verified performance results.

Buchner moved to California in 2019 for Stanford Graduate School of Business, founded Trunk Tools in 2021 while enrolled there and graduated in 2022, Crunchbase News reported. She said the company did not reach its first meaningful product-market fit until 2023, as advances in large language models made it more practical to work with large volumes of unstructured material.

That timing matters. Construction projects can generate millions of pages of documentation, Buchner said, and missed details can create delays, rework or unexpected costs. Trunk Tools’ bet is that AI tailored to those records can help teams spot relevant information before work proceeds.

The early fundraising process was harder because she did not match investors’ usual image of a technology founder, Buchner told Crunchbase News. Over time, she viewed her field experience as an advantage: she had done the work of many prospective customers and could speak to the operational details behind the software problem.

On July 24, 2025, Trunk Tools said Insight Partners led its $40 million Series B, with Redpoint Ventures, Innovation Endeavors, Stepstone, Liberty Mutual Strategic Ventures and Prudence participating. The New York-based company said the money would support engineering, product and go-to-market expansion.

This story draws on original reporting from Crunchbase News.