How Big Tech Scales Databases: Sharding Explained
Ever wondered how apps like Twitter or Uber handle millions of users without crashing?
At some point, every system hits a limit — and one database just isn’t enough.
In this video, we break down how real systems scale using Sharding— in a simple, visual way.
You’ll learn:
• Why a single database becomes a bottleneck
• How sharding actually works
• How requests are routed
• What happens when you add more shards
• Why things can still break (hotspots 😬)
• And how systems start fixing that
No heavy theory. Just intuition + visuals.
If you're preparing for system design interviews or just curious how large-scale systems work — this will help.
Github Notes: https://github.com/TheEngineersLabOff...
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Next video: Consistent Hashing (this is where things get really interesting 👀)
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⏱️ Timestamps:
00:00 Intro
00:04 Why databases fail
00:26 What is sharding
01:02 How it works
01:33 Routing logic
01:56 Benefits
02:14 Adding new shards problem
02:33 Resharding strategies
03:50 Hotspot problem
04:25 Solution
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