How I Made JavaScript BLAZINGLY FAST 

I'm pretty sure that Prime is talking about my code when he says garbage collection.

Big fan of the more technical stuff like this

Man, you should definitely make more of those deep-dives, you have so much knowledge to share. If you could also drop a link to this code in the description, that'd be really useful. Thanks for the great tip!

Love auch JS deep dives. I am myself a C++ and now (partially because of you) Rust developer and like this performance stuff 😁 Since I just start using JS I like listening to JS ninjas like you are. This is much more interesting than most low level JS stuff on YT 😁 Thanks for your high octane videos ✌️

Awesome timing. Just learned about how Rust manages memory today so this will be a nice contrast!

YES Primeee back at it with the technical stuff. For me this is your best type of content and the streams that lead up to it are so much fun!

Really enjoy the technical stuff! As someone who has more than a casual relationship with JS, these kind of engaging technical analyses are super useful on a very regular basis

My favorite type of videos from you! I use JS all the time and see the spread pattern constantly, never thought to consider the GC impact under the hood but makes total sense!

I love it. Object pool is quite a popular technique in game engines to reuse npcs and so on. Please continue with this format

I am a junior dev, but even understanding only about 50% / 60% I am learning so much watching your videos, thanks for this incredible quality videos!

It’s crazy that I’ve watched your channel on twitch and RU-vid for years and learn something new every time I listen Thank you!

I really enjoyed this video and yes I would like to see more content where you do a code review just like this. RU-vid is filled with junior developer content. It is hard as an intermediate to find content that improves your skill set/skill level. I think with your knowledge base your technical review of code is extremely beneficial.

love all your videos, keep up the technical side and I love your Go content!

I love this! This is the data based advanced stuff that no one else on RU-vid really does. With realworld fang experience to back it too!

I'd love to see a conversation between you and the React devs about the "Immutable" philosophy. So many new objects, every single render, it hurts...

These are the primeagen videos I enjoy the most! Keep them coming

Please do these type of videos more. Love it

Great video, super smart way of showing off GC operations and how to work around them.

Mna, these kind of content is all I need!! Thanks for sharing. Performance, performance, performance!!! Learn how to dig inside the runner and understand what parts of your code is taking longer and then debug to get it better is what everyone should learn. I know it's advanced for a lot of people, but learn how to debug is an art that we all should give more attention to. Again, I'm 1000% for more content like this!!!

It was a great video, i would like to see more content like this. My opinion on the vid was that the setup could be shorter, the explanation of the code a bit longer and the ending was perfect! Performance is a difficult topic and these videos really help explain your thought process, please make more of them.

I wrote a streaming regex engine and it hammers the GC pretty hard because it needs to create an object for each state it passes through, and on any real text and expression it passes through a lot. I studied its perf because I thought I'd have to pool the state objects, but instead profiling showed that I was only spending ~20% of my time doing GCs. That's because v8's generational garbage collector is optimized for the collection of objects that are small, short-lived, and have a common structure/shape. Engineers should not shy away from using those kinds of objects!

Man I'm so grateful for you communicating this stuff in 10 min chunks so good ty sir

Super high quality video. One of your best yet

Hey Mr./Ms. video editor, loved the "Not sure what he wanted me to do here lol" :D I always forget most of the good content creators have an editor making these guys much better than they would be on their own. You are doing a good job btw, whoever you are.

It really worked for me after I look and try some tutorials, yours is the one that worked. Owe you a lot.

I loved this, I love your technical videos, MOAR CODE!!!

Love these walk throughs. Great to have more

Thanks for the content. I've been working on how to rework blockchains without so much promise dependency...love these thought experiments. Best...hope the Volcano experiment works out!

Personally I like the more technical videos you make. These walkthroughs and explanations are extremely valuable imo. And as always the editing is top-notch, Flip is the man.

Lots of the time people are writing code that's more IO bound than CPU bound, but it's still useful to know these tricks for the areas where you are in a hot CPU loop

Great stuff! Interesting to listen these more technical topics.

Oh Prime these technical JS deep dives are fire 🔥🔥🔥

this is exactly the kind of content needed, deep dive into certain things...

The amount of energy this guy can summon while talking about such dry topics is truly impressive

I have pressed all the buttons! I love these videos, I am incredibly interested in internals and how performance can be increased. Please dish out more!

I really like these break-down videos where you show us what not to do and what to do if we want to go BLAZINGLY fast!

Love this deep dive.. keep it technical, go deeeeeep sir, deeep!

Awesome & Greatness!! Very Excellent point!! That's why I sometimes, do not use Promises especially if it takes a lot of time.. But it all depends on the data how you use them and put them onto the objects.

IT WORKED, THANKS I'VE BEEN LOOKING FOR THIS FOREVER, BUT NO TUTORIAL COULD EXPLAIN IT AS YOU DID

This is the best content I have seen by you, do more like this!

I also like the technical stuff, feels really nice to understand better what's going on with the tools you are using. Would it also be possible to share a repo with this code?

I like it. Really inspiring concepts. Keep it up.

Really enjoyed this content! Would love more videos like this

More of this plz. CI jest runs have been killing us and this was cool to watch with that in mind

i’m here for this, the hot takes are just gravy

i love these king of videos .. keep going !

2:34 -- first time I have been unable to resist the call to hit subscribe. I have subscribed, Daddy Primeagen.

+1 more deep dives, this is the first video of yours I watched, and it was great

Awesome video, thanks for making this 🙏

Dude I love this video. Got to watch it again.

Love this stuff Prime

I'd love to see one of these showing the Promise issue you mentioned!

Man, this channel is the best 🎉

your amazing but that editor does wonders too, props to that dude/lady whoever he/she is xD

dude love this, please make more technical content like this.

As a newbie to programming I didn't not have a clue what the Primeagen was talking about, but I still really enjoyed it.

Thank you for explaining this thoroughly!

Hey Prime, I checked out your course on Frontend Masters, but I don't wana pay for their monthly membership just for your courses - I'd rather just buy courses from you. Also, I would really love a comprehensive backend course (in Js(ts) and/or rust) from you. You're one of the most entertaining and technically competent programmers on youtube. I'd love to learn from you!

definitely a fan of these JS deep dives.

Love thiss .. keep em coming!! 😍

I love these science adjacent videos, they are like reading scientific articles but more fun

Really great content. Love it 😀

I'd like to see a more in-depth breakdown of how garbage collection works as pertains to promises, and how you circumvented promises altogether. Good stuff

Love the more technical deep dives

This is great thanks. I usually don't worry too much about it since if I'm using JavaScript it's not in a performance = money scenario

Prime!! Sending you some algorithmic clues to show more code

Great video!! Though I’m extremely curious about the refactor of the promises and that performance gain, can you elaborate more on it apart from GC taking so much time? I’d love a video about this :) Great job, love your channel 🔝

I didn't understand half of it, but this was a pretty interesting video. I think i will look into this more. Thank you for sharing

love this type of videos!

DAMN! Finally I found someone who teach like a savage! Usually I find myself sleeping right after couple of minutes of *explaining* something, here in a turn, I want to break my fckn retina display like rock star breaks his guitar! BTW didn't understand how you implemented test example, but it doesn't matter!

I’ve heard that reference counting is a good strategy for UI’s. Would this mean that front end apps could get better performance with Rust and Wasm using ref counting (as wasm catches up with V8)?

We love this type of videos 😍😍

Thank you for this! Super cool video! A+++

the deepest video about JS I've ever watched lol, now I know that I have a long road before me to become like you @ThePrimegen

Love this content. Learn good stuff

Genuine q's, are there any benefit of using ts/js in backend? I always thought that if I wanted performance, I would use something else.

Thank you, Mr. ThePrimeagen!

I liked the video only because you send me to read the description and the way you requested was funny 😂

Yay on the technical vids/amount of code. Made happy brain chemicals

I LOVE it! Please more technical stuff! PRIME, I AM SENDING YOU THE ALGORITHMIC SIGNALS PRIMMEEEEE!!!!

More please. I like this kind of stuff.

you are way too funny =) and also smart!! great job!!

Please!!!! More technical videos like this one 🙏🙏🙏

that's why pure functions are advised and returning callbacks is disadvised

Yeah, tech-heavy videos are great. Code is life

Favorite vid so far 😃

This is great, thank you!

So informative. Thank you

actual technical content about a language that no one really thinks about technically is the true performance optimization involved here

Prime always missing the actual place of like button. Every time he says "it's there just press it" he points to some random direction :D

Amazing stuff! For more profiling like that!!!

thanks a lot!!! so nice reverb

These kind of videos are educational thanks

How/Where do you start learning all this stuff???? So much in-depth knowledge and its really fascinating. Makes me wanna go indepth too

Thank you, it works perfect!

I actually experimented with this when I try to port RPython to wasm. Basically leaking all the memory to do 1 full stack execution, and then shrink the memory back to the initial state in the next tick (setImmediate or setTimeout) is tons faster than applying GC algorithm and libraries even bigger one like boehm.

This is the only video you made I have enjoyed.

Would really appreciate it if you can make a video on why/how/when ditch promise to better performance

Still interesting, still funny, still a great teacher.

The idea of an object pool in a library like fastly sounds like (if I understand correctly) it would be incredibly easy to misuse, because the user needs to be very careful when to release the request object. On the one hand, if you release it too early/hold onto the object for too long and (for example) use it across an await point, the JS engine may well execute another request and it could reuse the released object (and effectively write request data of the new request to the object which is still in use by the other request). Then once it goes back to executing the old request, it has all the request data from the new request. On the other hand if you forget to release the object, it "leaks".This sounds almost like manual memory management but in JS