# Anders Hejlsberg (creator of TypeScript) reacts to the 2025 Octoverse report Source: https://www.youtube.com/watch?v=GMWJceUTxuk Recap page: https://rapidrecap.app/video/GMWJceUTxuk Generated: 2025-11-10T22:02:24.216+00:00 --- ## Quick Overview TypeScript's lead architect, Anders Hejlsberg, expresses surprise and gratitude regarding TypeScript's massive growth as detailed in the 2025 Octoverse report, noting that the primary driver for the next evolution is scaling challenges, leading to the decision to port the compiler to Go for performance benefits, and he confirms that AI is currently assisting developers by automating tasks like language porting and providing deterministic outcomes, fundamentally changing the developer workflow. **Key Points:** - Hejlsberg was floored by TypeScript's growth, noting the team is grateful and that the project is certainly relevant to many people. - The current primary challenge for TypeScript is scalability, especially with the ever-growing size of user-built projects, making performance the number one issue. - To address scaling, the TypeScript compiler is being ported to Go, ensuring functional parity with the old compiler but achieving a 10x performance boost, which is necessary because the community cannot just ignore such performance demands. - AI is already changing workflows by acting as an assistant that helps developers complete tasks faster, such as automating code generation or translation between languages like TypeScript and Go. - The ability of AI to generate deterministic outcomes for complex tasks like porting half a million lines of code is a significant advancement, moving beyond simple code completion in an IDE. - Hejlsberg suggests that the best language for AI to target for creation/porting is one that AI has already seen a lot of, such as JavaScript or Python, implying new languages are at a disadvantage. - The move to Go for the compiler, while maintaining functional equivalence, will dramatically change development tools by enabling faster, more reliable processes. ![Screenshot at 00:14: Anders Hejlsberg reacting with surprise and pleasure to the graph showing TypeScript's massive growth trajectory leading up to 2025, a key moment where he acknowledges the project's success.](https://ss.rapidrecap.app/screens/GMWJceUTxuk/00-00-14.png) **Context:** Anders Hejlsberg, the Lead Architect of TypeScript at Microsoft, discusses the recent 2025 Octoverse report findings regarding TypeScript's popularity and the future direction of the language, particularly focusing on performance bottlenecks due to massive adoption and how the team is addressing these issues, including the strategic decision to rewrite the compiler in Go and the increasing role of Artificial Intelligence in developer tooling. ## Detailed Analysis Anders Hejlsberg expresses genuine surprise and deep gratitude for the immense growth of TypeScript, referencing the 2025 Octoverse report data which shows its trajectory, possibly surpassing JavaScript. He states that the biggest issue now is scalability, as projects are becoming too large for the existing compiler infrastructure to handle efficiently. To solve this, the team is porting the TypeScript compiler to Go, a process that must yield a 10x performance improvement while maintaining functional equivalence to the original compiler, ensuring that the core behavior remains the same down to the quirks. Hejlsberg emphasizes that this move is essential because the community's demand for performance cannot be ignored. Regarding AI, he notes that it has evolved from a simple assistant providing basic code completion in the IDE to a tool capable of automating complex, multi-million line code ports between languages, leading to deterministic outcomes. He believes this shift will drastically change development tools, making processes like porting code much faster. He concludes that the best language for AI to learn from is one it has seen extensively, meaning languages like JavaScript and Python are currently favored over newer ones for AI-assisted generation. ### Reaction to 2025 Octoverse Report - Hejlsberg is floored by TypeScript's growth and grateful for its relevance - Initial adoption goals were modest (perhaps 25% of the community) but success far exceeded expectations. ### The Scalability Challenge - Massive adoption size of user projects has made performance the number one issue - Self-hosting the compiler proved insufficient for handling the scale. ### Compiler Port to Go - The team is porting the compiler to Go to achieve a 10x performance improvement - The goal is functional parity, meaning the Go compiler must produce exactly what the old compiler did, including quirks. ### Impact of AI on Development - AI started as an assistant but now automates complex tasks like porting large codebases (half a million lines) deterministically - This fundamentally changes developer workflows and tooling. ### AI's Role in Language Creation - AI's ability to generate new languages or target existing ones depends on training data - Languages like JavaScript and Python are better suited for AI generation because AI has seen more of their code historically. ![Screenshot at 00:02: Title screen introducing Anders Hejlsberg and the topic: his reaction to the 2025 Octoverse report.](https://ss.rapidrecap.app/screens/GMWJceUTxuk/00-00-02.png) ![Screenshot at 00:05: Anders Hejlsberg identified as Lead Architect of TypeScript, Microsoft, speaking about the project's success.](https://ss.rapidrecap.app/screens/GMWJceUTxuk/00-00-05.png) ![Screenshot at 00:14: A graph titled 'Top five programming languages on GitHub' showing TypeScript's steep growth curve, especially after early 2025, coinciding with the release of Copilot Free.](https://ss.rapidrecap.app/screens/GMWJceUTxuk/00-00-14.png) ![Screenshot at 00:28: Text overlay posing the question: 'Why is TypeScript moving to Go?' highlighting the core technical decision discussed.](https://ss.rapidrecap.app/screens/GMWJceUTxuk/00-00-28.png) ![Screenshot at 01:01: A timeline graph showing the 'Top 10 programming languages on GitHub 2023-2025', illustrating the competitive landscape and TypeScript's rise.](https://ss.rapidrecap.app/screens/GMWJceUTxuk/00-01-01.png) ![Screenshot at 01:45: Text overlay posing the question: 'How has open source evolved?', setting up the discussion on community and sustainability.](https://ss.rapidrecap.app/screens/GMWJceUTxuk/00-01-45.png) ![Screenshot at 02:50: Text overlay posing the question: 'Is AI changing how languages are created?', transitioning to the topic of AI's role.](https://ss.rapidrecap.app/screens/GMWJceUTxuk/00-02-50.png) ![Screenshot at 03:34: Text overlay posing the question: 'How is AI being implemented in porting TypeScript to Go?', detailing AI's specific use case in compiler migration.](https://ss.rapidrecap.app/screens/GMWJceUTxuk/00-03-34.png) ![Screenshot at 04:32: Text overlay posing the question: 'How has AI changed a developer's workflow?', summarizing the practical impact of AI tools.](https://ss.rapidrecap.app/screens/GMWJceUTxuk/00-04-32.png)