TypeScript, C# and Turbo Pascal with Anders Hejlsberg
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Anders Hejlsberg is a living legend and one of the most influential programming language designers of all time. He created Turbo Pascal, Delphi, C#, and also TypeScript. As well as that, he spent nearly a decade at the pioneering dev tools company, Borland, and is now in his 30th year of working at Microsoft, where he’s a Technical Fellow.
In this episode, we discuss what it takes to build programming languages that developers love to use, and trace his career from writing his first compiler to creating Turbo Pascal and Delphi, and helping to pioneer modern software development through C# and TypeScript.
Anders details how C# was designed by a small group of experienced language designers who met a few hours each week, and he explains why tooling was just as important as the language for TypeScript’s success, and what he has learned from building languages which stay relevant for decades.
We also look into how Anders uses AI today, which language features suit AI-assisted development, and what he thinks is changing in the craft of software engineering as developers move further away from writing code line by line.
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Timestamps
(00:00) Intro
(02:48) How Anders got into programming
(05:40) Building his first compiler
(07:44) Turbo Pascal
(12:25) Delphi
(14:53) Joining Microsoft
(19:41) Building C#
(29:11) Async/await
(34:01) The rise of JavaScript
(37:52) Building TypeScript
(42:58) How the TypeScript compiler works
(48:30) JavaScript’s strengths and weaknesses
(52:18) How Anders uses AI
(56:03) What language features work well with AI
(1:02:49) How software craftsmanship is changing
(1:07:49) Performance and efficiency
(1:09:29) Anders’ tool stack
(1:11:30) A 30-year career at Microsoft
(1:13:40) Book recommendation
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The Pragmatic Engineer deepdives relevant for this episode:
• Microsoft’s developer tools roots
• 50 Years of Microsoft and developer tools with Scott Guthrie
• How Linux is built with Greg Kroah-Hartman
• How will AI change operating systems? Part 1: Ubuntu and Linux
• How Uber uses AI for development: inside look
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884: Typescript Just Got 10x Faster
Wes and Scott talk with Anders Hejlsberg and Daniel Rosenwasser about TypeScript’s leap to native code. They discuss the challenges, trade-offs, and the decision to port TypeScript to Go, unlocking faster compilation, better concurrency, and new possibilities for AI-assisted development.
Show Notes 00:00 Welcome to Syntax!
00:38 TypeScript compiler goes native
05:24 Challenges in rebuilding TypeScript
08:49 How long has this been in development?
10:32 What does porting TypeScript to native entail?
16:36 Why choose Go?
26:48 The porting process
35:02 Brought to you by Sentry.io
35:27 Type checking and parallel compilation
42:36 Fixing TypeScript’s performance bottlenecks
49:09 Large TypeScript codebases
54:11 What’s the timeline for the new compiler?
58:39 Optimization and AI
01:00:32 New features?
01:04:15 Sick Picks + Shameless Plugs
Sick Picks Daniel: pprof-it
Anders: USB Hand Warmers
Shameless Plugs TypeScript
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TypeScript and open source at Microsoft (Interview)
Anders Hejlsberg and Jonathan Turner from the TypeScript team at Microsoft joined the show to talk about TypeScript, a typed superset of JavaScript that compiles to plain JavaScript from Microsoft. We cover Microsoft’s acceptance and support of open source, why they open sourced TypeScript, the language design, adoption, how to get started, and the future of the language.
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Featuring:
Anders Hejlsberg – GitHub, X
Jonathan Turner – Website, GitHub, X
Adam Stacoviak – Website, GitHub, LinkedIn, Mastodon, X
Jerod Santo – Website, GitHub, LinkedIn, Mastodon, X
Show Notes:
Anders is the language architect and Jonathan is the Program Manager for TypeScript.
Roadmap · Microsoft/TypeScript Wiki
Microsoft/TypeScript
Welcome to TypeScript
Follow Jonathan Turner on Twitter
Follow Anders Hejlsberg on Twitter
Delphi (programming language) - Wikipedia, the free encyclopedia
Turbo Pascal - Wikipedia, the free encyclopedia
Handbook - Welcome to TypeScript
Microsoft/TypeScript-Sublime-Plugin
palantir/eclipse-typescript
atom-typescript
borisyankov/DefinitelyTyped
Home | DefinitelyTyped
TypeScript/spec.md at master · Microsoft/TypeScript
Algorithms + Data Structures = Programs (Prentice-Hall Series in Automatic Computation): Niklaus Wirth: 9780130224187: Amazon.com: Books
Niklaus Wirth - Wikipedia, the free encyclopedia
Architectural Overview · Microsoft/TypeScript Wiki
The Changelog #134: Open Sourcing .NET Core with the Microsoft .NET team
The Changelog #148: The State of Go in 2015 with Andrew Gerrand
The Changelog #151: Rust with Steve Klabnik and Yehuda Katz
Monaca
Gerrit Code Review
Something missing or broken? PRs welcome!
