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And with that we're done,

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now let me briefly sum up what we learned

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We had a look at runtime performance and potential improvements we can implement there.

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You should avoid unnecessary code executions, batch operations together and avoid unnecessary DOM

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access as you learned. You should

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of course also find and fix memory leaks, even small ones because they can add up and make your page

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slower or make it crash. For high frequency operations,

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you can compare different approaches, like the two for loop alternatives

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we had a look at and use the faster one

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and in general you might consider micro optimizations but you should also be careful about them because

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performance isn't a fixed thing, it can change in the future and you might be optimizing for something

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which really doesn't matter. When we have a look at startup performance,

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then we want to eliminate unnecessary or unused code, to download as small of a code package initially

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as possible.

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You also want to avoid using too many third-party libraries for that reason because every third-party

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library you add is extra code which needs to be downloaded and parsed, so the more third-party libraries

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you load, the more code you have to download. If you use third-party libraries, you also want to consider

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importing them into your script files and then using webpack for bundling and code splitting instead

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of using CDN links because if you use CDN links, you can't use code splitting.

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So bundling code and using lazy loading here really is a great idea for ensuring that your code starts

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fast and is able to execute as early as possible.

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Of course you should

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also minify code and webpack does this automatically to ensure that you ship as little code as possible

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to your end users

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and this is really it.

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You saw a lot of examples throughout this module,

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i hopefully could introduce you to how you should think about performance optimizations.

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You also got some useful external resources where you can dive deeper and in general, performance optimization

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is a topic which you can't really master,

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it's an ongoing journey,

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there are always new things to explore and it's also very specific to your exact use case.

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It's always very specific to that regarding what you want to look into and what you might want to consider

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optimizing.

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You can also google for Javascript performance optimizations and you will find many examples, some

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which you already saw here, some which you didn't.

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This can also be interesting to learn more about this topic but always also keep in mind that you shouldn't

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overdo it,

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you want to improve your application, you want to fix bugs and leaks but you don't want optimize every

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tiny bit because you could end up with code which is actually longer than before and therefore adds

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to the bundle size or you implemented an optimization which isn't optimal anymore in the future.

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Still, this hopefully got you started and i showed you some of the most important and critical aspects

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when it comes to performance optimizations and what you should keep in mind

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there.