World's Fair 2026
A Song of Types and Agents - Roberto Stagi, Ratel
Overview
This talk argues that TypeScript is increasingly becoming the dominant language for building AI applications, particularly for the application and agent layers, despite Python's continued strength in model training and infrastructure. The shift is driven by the rise of coding agents and the need to integrate AI capabilities directly into applications, a domain historically dominated by TypeScript.
Who should watch
- AI Engineers
- Product Managers
- Developers building AI-powered applications
- Those interested in the evolution of programming languages in AI
- Builders looking to integrate AI agents into their products
Key takeaways
- Python remains the primary language for AI model training, research, and GPU serving infrastructure.
- TypeScript is emerging as the preferred language for the application layer, including AI agents, due to its prevalence in web development and the rise of coding agents.
- Coding agents, such as Lava, Cloud Code, and Cursor, are increasingly built using TypeScript, driving its adoption for AI applications.
- Using TypeScript for AI agents allows for a single codebase across the agent loop, tools, backend, and UI, simplifying development compared to Python-based architectures that often require separate frontends.
- TypeScript offers consistent typing across the entire application stack, utilizing tools like Zod for schema definition, which contrasts with the potential typing boundary issues when integrating Python backends with JavaScript frontends.
- The NPM ecosystem provides a rich set of packages for authentication, payments, UI, and infrastructure, which are readily accessible when building in TypeScript.
- The AI ecosystem is rapidly growing, with tools like the Versatile AI SDK showing significant increases in adoption, further supporting TypeScript's role.
- Jeff Atwood's law, *Any application that can be written in JavaScript will eventually be written in JavaScript*, is extended to TypeScript, suggesting its eventual dominance in application development.
Notable quotes
*Python has its own application. Like I still think that the brain of the of the agent and all the of all the AI world is actually still owned by Python.*
*The application layer has been TypeScript's for pretty long time now.*
*Any application that can be written in JavaScript will eventually be written in JavaScript.*
Unofficial community note. Prefer the recording for nuance.