Kafka, caching, load balancing, sharding — every backend concept as a living diagram you can follow, not a wall of text.
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System design questions, HLD & LLD frameworks, and company-wise sets for Google, Amazon, Flipkart and more.
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Every architecture diagram — Redis, Kafka, OAuth, load balancers, CQRS, SAGA — zoomable, downloadable, explained.
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Premium simulators & calculators — tweak the inputs, watch the system react.
Interactive nodes, difficulty tags, estimated time and a resource for every step. Track your progress as you go.
Open the roadmap →The hidden cost of poll timeouts — and how to size your consumer groups correctly.
Choosing a shard key, and the migration nightmares that follow a wrong one.
The two hard problems — and a mental model that makes the first one easy.
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