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See this?
This is the YouTube home page.
Let's focus on the main feed.
This is where the evil algorithm recommends videos you would binge-watch and waste hours on.
As a fullstack developer, how would you implement this feature?
I'm not talking about showing the thumbnail, preview, or all that stuff.
How do you implement infinite scrolling?
You need to, probably:
In the frontend: fetch videos (metadata like thumbnail, link to the actual video, title, etc) from a server.
In the server API: query the videos from the database.
Lucky for you, there's a Video Pool table for every user. It includes 1000 videos that they are most likely to watch.
Should you send back those 1000 videos to the frontend?
Maybe?
What does the frontend need? Loading all 1000 video thumbnails at once is not a good idea because image loading takes lots of time.
How do you load less video while providing a good user experience?
On the initial page load: The frontend only needs to display a reasonable amount of video, like 20.
When the user scrolls past that: It fetches the data and loads the next 20 videos.
This is the fundamental idea of pagination, a commonly used technique in software engineering. Rather than sending a huge amount of data all at once, you split it into smaller chunks called pages.
This approach has two clear benefits:
It shows content faster. Users are happier.
It reduces the server load and data transfer time because you are sending back less data.
You will see pagination everywhere:
Product pages with page numbers
Infinite scrolling on social media
A “More Results” button on Google Search mobile
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Now you understand what pagination is, next week we will go over how to implement it.
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