Marvin Hagemeister
marvinh.dev · Personal blog · on HN since 2022
Marvin Hagemeister is a JavaScript developer who writes about profiling and speeding up the JS ecosystem, including polyfills and tooling.
What HN saysCommenters call the series nice and ask about his profiling method; others debate his points on polyfills and developer experience versus user performance.
20HN people shared it
4linked it in comments
22stories submitted
153story points
10 months agolast shared
2022people per year2026
Most-shared posts
- 1Speeding up the JavaScript ecosystem – Polyfills gone rogue3 people · 33 points · first shared 2023 · 12 comments on HN
- 2Speeding up the JS ecosystem - npm scripts3 people · 5 points · first shared 2023 · 1 comments on HN
- 3Speeding up the JavaScript ecosystem – one library at a time3 people · 1 points · first shared 2022 · discussion on HN
- 4Running 1000 tests in 1s (JS)2 people · 5 points · first shared 2023 · 1 comments on HN
- 5Speeding up the JavaScript ecosystem part 2 – Module Resolution2 people · 5 points · first shared 2023 · discussion on HN
- 6Speeding up the JavaScript ecosystem – Isolated Declarations1 people · 45 points · first shared 2024 · 54 comments on HN
- 7Speeding up the JavaScript ecosystem – Semver1 people · 23 points · first shared 2025 · discussion on HN
- 8Speeding Up the JavaScript Ecosystem – Server Side JSX1 people · 15 points · first shared 2024 · 1 comments on HN
- 9Speeding up the JavaScript Ecosystem: JavaScript plugins for Rust tools1 people · 5 points · first shared 2025 · 1 comments on HN
- 10Speeding up the JavaScript ecosystem – The barrel file debacle1 people · 3 points · first shared 2023 · discussion on HN
- 11Building from First Principles1 people · 2 points · first shared 2025 · discussion on HN
- 12Speeding up the JavaScript ecosystem – Tailwind CSS1 people · 2 points · first shared 2023 · discussion on HN
- 13Speeding up the JavaScript ecosystem part 3 – eslint1 people · 2 points · first shared 2023 · discussion on HN
- 14Speeding up the JavaScript ecosystem – draft-JS emoji plugin1 people · 2 points · first shared 2023 · discussion on HN
- 15The modern way to write JavaScript servers1 people · 2 points · first shared 2025 · discussion on HN
What HN people wrote when they linked it
jazzypants · 2025-11-29
I'm sorry, but this is just incorrect. Have you ever heard of ljharb[0]? The NPM ecosystem is rife with polyfills[1]. I don't know how you can make a distinction on which libraries would be used for "local scripting" as I don't think many library authors make that distinction.
[0] - TC39 member who is self-described as "obsessed with backwards compatibility": https://github.com/ljharb
[1] - Here's one of many articles describing the situation: https://marvinh.dev/blog/speeding-up-javascript-ecosystem-part-6/
gryzzly · 2024-04-11
Generally very few people care, unless it’s "an impact metric" tied to that team. Or there is a "performance sprint" or something. "DX" has been more important than "UX" in the current mainstream JS community for a while. To give an example: babel, that enabled syntactic sugar, also caused many versions of runtime implementations of various ES6+ syntax to end up in bundles, or polyfills for browsers the clients aren’t actually using etc.
You can read more about the things that are absolutely mainstream and are problems in very popular libraries in the "Speeding Up JavaScript" series from Marvin Hagemeister – like this one https://marvinh.dev/blog/speeding-up-javascript-ecosystem-part-6/
Also, most devs are testing on powerful devices, and there is a big disconnect between their experiences and that of their users – https://infrequently.org/2021/03/the-performance-inequality-gap/
pests · 2023-09-24
Back then network speeds were less and latency higher. Sending a runtime to the client and reducing the network traffic thereafter was a big win back then.
Over time the network has improved, removing the benefit of the reduced network traffic.
We still pay the runtime performance impact though. Its morphed into what modern frameworks are today and the original benefit was forgotten. Execution times have only gone up.
So with faster network speeds and increased execution time - its been flipped. It's not that it feels super fast. It's that it is super fast.
Not to mention the web is almost unoptimized. Lots of very low hanging fruit. Early this year someone wrote a series of articles[1] demonstrating how much he could imnprove just by simply looking.
[1] https://marvinh.dev/blog/speeding-up-javascript-ecosystem/
pbowyer · 2023-09-22
This is a really nice post and series. I'm curious how you're doing the profiling and then generating the flame graphs e.g. in https://marvinh.dev/blog/speeding-up-javascript-ecosystem/. Is this Chrome's built-in devtools being used or something else?