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System design concepts that show up in every system design interview. From CAP to consistent hashing - what it is, when it bites, how to talk about it.

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Dependency Injection
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Dependency Injection

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2:22
04 / 06 · 2:22 · System Design

Dependency Injection

Dependency Injection makes code testable, flexible, and loosely coupled. Learn the core principle that transforms tightly-coupled classes into maintainable systems, without any framework required.

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DB

Database Design

Building now

Videos covering the core database concepts and topics that interviewers usually probe: indexes, query plans, isolation, replication, sharding and more

DS

Distributed Systems

Coming soon

Quorums, Paxos/Raft intuitions, vector clocks, gossip - the building blocks behind every distributed system question.

FP

Frontend Performance

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Web vitals, render-blocking resources, hydration cost, image strategy - the levers that move real Lighthouse scores.

AU

Auth & Identity

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Session vs JWT tradeoffs, OAuth2/OIDC flows, refresh strategies, and the most common security footguns to talk about.

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