Riza introduces Custom Runtimes, a feature that enables users to execute code using any Python or JavaScript/TypeScript package dependencies, overcoming the limitations of standard libraries. This new capability allows developers to utilize packages from PyPI and npm, such as pandas for data analysis or cheerio for HTML data extraction, enhancing the versatility of applications built on Riza. Users can create Custom Runtimes either through the Riza Dashboard or via API by specifying required packages in formats like requirements.txt or package.json. Once a Custom Runtime is defined, Riza generates an immutable Runtime Revision containing the specified packages, which can then be used to run code through the Execute Code API Endpoint. Developers can update dependencies by creating new Runtime Revisions without affecting existing code, and the feature is available for all users, with the Hobby Plan offering up to ten Custom Runtimes.