What are the key takeaways from this Software Engineering Daily episode?

Key insights include: **TypeScript 7 performance gains:** The rewrite from TypeScript to native Go delivers approximately 10x faster build speeds on most codebases by combining native compilation with shared memory, parallelism, and multi-core saturation. Teams at Slack, Vanta, and internal Microsoft groups with massive codebases report near-instantaneous builds where previously they waited minutes for editor load.; **Adopting TypeScript 7 today:** Developers not using Vue, Angular, or language server plugins can install TypeScript 7 immediately via the VS Code extension or equivalent editor support. TypeScript 7 and TypeScript ESLint for version 6 can run side by side, and Johnny Riley has already demonstrated TypeScript 7 working with Webpack through early nightly API builds.; **IPC boundary replaces direct API access:** TypeScript 7.1 introduces an inter-process communication boundary instead of direct in-process API access. This design allows multiple clients — linters, editors, build tools — to share a single compiler session and memory view, reducing duplication across tools regardless of whether they are written in JavaScript, Rust, or another language.

What did Daniel Rosenwasser and Josh Goldberg discuss on Software Engineering Daily?

Daniel Rosenwasser, Principal Product Manager of TypeScript at Microsoft, joins host Josh Goldberg to cover TypeScript 7's rewrite in Go, the resulting 10x performance gains, the new IPC-based API boundary, TypeScript's relationship with TC39's ECMAScript standardization process, and how LLMs may reshape type checking and linting tooling. Key topics include: **TypeScript 7 performance gains:** The rewrite from TypeScript to native Go delivers approximately 10x faster build speeds on most codebases by combining native compilation with shared memory, parallelism, and multi-core saturation. Teams at Slack, Vanta, and internal Microsoft groups with massive codebases report near-instantaneous builds where previously they waited minutes for editor load.; **Adopting TypeScript 7 today:** Developers not using Vue, Angular, or language server plugins can install TypeScript 7 immediately via the VS Code extension or equivalent editor support. TypeScript 7 and TypeScript ESLint for version 6 can run side by side, and Johnny Riley has already demonstrated TypeScript 7 working with Webpack through early nightly API builds..

How long is this episode of Software Engineering Daily?

This episode is 57 minutes long. SignalCast provides an AI-generated summary so you can get the key insights in about 3 minutes.

Software Engineering Daily

TypeScript 7 and What Comes Next

August 27, 2026

57 min episode · 2 min read

Daniel Rosenwasser,Josh Goldberg

Episode

57 min

Read time

2 min

Topics

Remote Work, Relationships, Leadership

AI-Generated Summary

Published Aug 27, 2026

Key Takeaways

✓TypeScript 7 performance gains: The rewrite from TypeScript to native Go delivers approximately 10x faster build speeds on most codebases by combining native compilation with shared memory, parallelism, and multi-core saturation. Teams at Slack, Vanta, and internal Microsoft groups with massive codebases report near-instantaneous builds where previously they waited minutes for editor load.
✓Adopting TypeScript 7 today: Developers not using Vue, Angular, or language server plugins can install TypeScript 7 immediately via the VS Code extension or equivalent editor support. TypeScript 7 and TypeScript ESLint for version 6 can run side by side, and Johnny Riley has already demonstrated TypeScript 7 working with Webpack through early nightly API builds.
✓IPC boundary replaces direct API access: TypeScript 7.1 introduces an inter-process communication boundary instead of direct in-process API access. This design allows multiple clients — linters, editors, build tools — to share a single compiler session and memory view, reducing duplication across tools regardless of whether they are written in JavaScript, Rust, or another language.
✓TC39 stage-three rule governs TypeScript features: TypeScript only implements new JavaScript syntax once a proposal reaches TC39 stage three, signaling implementer readiness. All TypeScript-specific additions beyond that must be erasable syntax — strippable without altering runtime behavior — preventing the breaking rewrites that plagued early features like decorators when proposals changed semantics mid-implementation.
✓LLMs may enable on-demand lint rule generation: Rosenwasser frames a concrete near-term shift: teams currently skip writing custom lint rules because the effort outweighs the benefit. With LLMs able to generate ESLint-style rules on demand from a plain-language description, the TypeScript 7.1 API becomes more valuable as the shared infrastructure those generated rules would consume at scale.

What It Covers

Daniel Rosenwasser, Principal Product Manager of TypeScript at Microsoft, joins host Josh Goldberg to cover TypeScript 7's rewrite in Go, the resulting 10x performance gains, the new IPC-based API boundary, TypeScript's relationship with TC39's ECMAScript standardization process, and how LLMs may reshape type checking and linting tooling.

Key Questions Answered

•TypeScript 7 performance gains: The rewrite from TypeScript to native Go delivers approximately 10x faster build speeds on most codebases by combining native compilation with shared memory, parallelism, and multi-core saturation. Teams at Slack, Vanta, and internal Microsoft groups with massive codebases report near-instantaneous builds where previously they waited minutes for editor load.
•Adopting TypeScript 7 today: Developers not using Vue, Angular, or language server plugins can install TypeScript 7 immediately via the VS Code extension or equivalent editor support. TypeScript 7 and TypeScript ESLint for version 6 can run side by side, and Johnny Riley has already demonstrated TypeScript 7 working with Webpack through early nightly API builds.
•IPC boundary replaces direct API access: TypeScript 7.1 introduces an inter-process communication boundary instead of direct in-process API access. This design allows multiple clients — linters, editors, build tools — to share a single compiler session and memory view, reducing duplication across tools regardless of whether they are written in JavaScript, Rust, or another language.
•TC39 stage-three rule governs TypeScript features: TypeScript only implements new JavaScript syntax once a proposal reaches TC39 stage three, signaling implementer readiness. All TypeScript-specific additions beyond that must be erasable syntax — strippable without altering runtime behavior — preventing the breaking rewrites that plagued early features like decorators when proposals changed semantics mid-implementation.
•LLMs may enable on-demand lint rule generation: Rosenwasser frames a concrete near-term shift: teams currently skip writing custom lint rules because the effort outweighs the benefit. With LLMs able to generate ESLint-style rules on demand from a plain-language description, the TypeScript 7.1 API becomes more valuable as the shared infrastructure those generated rules would consume at scale.

Notable Moment

Rosenwasser reveals that TypeScript's early decorator implementation had to be rewritten multiple times as the TC39 proposal changed semantics, forcing users to rewrite their own code across versions — a painful lesson that directly produced the current strict stage-three-only policy for implementing JavaScript syntax.

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Episode Transcript

TypeScript is a programming language that builds on JavaScript by adding a system of types. Those types let developers describe the shape of their data and catch mistakes before code ever runs, while also powering the auto completion and editor tooling that many developers now rely on every day. It was first released in 2012 and has since become one of the most widely used tools in web development. TypeScript recently underwent one of the most significant changes in its history with the release of version seven. Daniel Rosenwasser is the principal product manager of TypeScript at Microsoft, where he began as an engineer on the team just weeks after the TypeScript one point o release. In this episode, Daniel joins Josh Goldberg to talk about the features of TypeScript seven. They discuss the TypeScript team's approach to tooling, TypeScript's relationship with the TC 39 standards process behind JavaScript, the new API and IPC boundary, how LLMs could reshape type checking and linting, and more. This episode is hosted by Josh Goldberg, an independent full time open source developer. Josh works on projects in the TypeScript ecosystem, most notably TypeScript ESLint, a powerful static analysis toolset for JavaScript and TypeScript. He is also the author of the O'Reilly Learning TypeScript book, a Microsoft MVP for developer technologies, and a cofounder of SquiggleComp, a conference for excellent web developer tooling. Find Josh on BlueSky, fostidon,and.com as Joshua k Goldberg. With me today is Daniel Rosenwasser, principal product manager of TypeScript at Microsoft. Daniel, welcome to Software Engineering Daily. Thank you so much for having me. Great to talk to you today, Josh. Yeah. We're really excited to have you. I've been looking forward to this. There's a lot of cool stuff happening in TypeScript, both with the recent releases and then upcoming upcoming work. But before we dive into that wonderful world, Daniel, how did you get into tech? How did you get into tech? Oh, I feel like this is a very common one for a lot of people, you know, video games, things like that. And then getting a little bit more and more and more curious about all the sorts of things and how they work and thinking, oh, maybe I could do this or that. But I think the funny thing was, for me with well, I I mean, maybe programming specifically, the way I got into a lot of that was through just maybe the earliness of the Internet and then just meeting random people on forums and probably being a little bit too young to be on, like, a video game forum at the time. Right? Like, I don't know. Maybe 10, 11 years old or something like that. But meeting these random people from around the world and then finding out that they were, you know, 15, 16, 17 years old and running a forum themselves and and realizing, like, hold on a second. You're all a bunch of teenagers running a website, and …

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