System Design
Scalability & Load Balancing
7 practice questions. Free questions open a full answer guide; the rest unlock with Pro.
- Design a distributed job scheduler that can run millions of cron jobs reliably, at scale, across many worker nodes.
- Design the backend for a social news feed (like the home timeline on X or Instagram) where users follow others and see a ranked feed of recent posts. Some accounts have tens of millions of followers.Go Pro
- A product launch is expected to drive a 20x traffic spike over a few minutes, far faster than autoscaling can react. How do you design the load-balancing and capacity layer to survive it without falling over?Go Pro
- Design a scalable offline model training platform that supports 50 data scientists running experiments concurrently.Go Pro
- You're designing the data platform for a company that needs to support both real-time analytics (sub-second queries) and batch ML training (petabyte-scale). How do you architect the Lambda or Kappa architecture for this?Go Pro
- How do you choose and configure the load balancer in front of a service — what factors decide the type and the routing strategy?Go Pro
- Our API runs on one beefy server and we need it to handle ten times the traffic. How do you scale it out horizontally, and what has to change in the application to make that work?Go Pro
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