The Zestimate is generated through a series of processes built using various tools, including heavy doses of R, Python, Pandas, Scikit Learn, and GraphLab Create, the graph analytics software developed by Seattle-based Dato (formerly GraphLab).

The company makes extensive use of R, including the development of a proprietary software package called ZPL that functions similar to MapReduce on Hadoop, but runs on a relational database. The company is increasing its use of Python, which Zillow data scientists say is better than R for some things, such as conducting GIS analysis.