System design · Deep dives
The techniques that keep coming up
6 ideas interviewers circle back to. Watch each one play out, push it in a widget, then keep the trade-offs.
Got a minute?12 one-minute shorts on these techniques. One idea per card, swipe for the next.
Open shorts- 01 20 min
Caching Techniques
A cache trades freshness and memory for speed. The technique you choose decides what happens when the cache is stale, cold, or down.
Open the deep dive - 02 20 min
Sharding Strategies
Sharding splits data across machines so no single database limits storage or write throughput. The shard key you pick is the most important decision.
Open the deep dive - 03 20 min
Storing Data: Choosing the Right Store
No single database is best at everything. Match each kind of data to the store whose strengths fit its access pattern, and keep one source of truth per fact.
Open the deep dive - 04 20 min
Polling, SSE and WebSockets
HTTP is request and response, but users expect live updates. Each technique trades simplicity against latency and server cost.
Open the deep dive - 05 20 min
Connections: Pooling, Keep-Alive and Limits
Connections are expensive and limited. Most production outages from load come from exhausted pools, missing timeouts, or unbounded concurrency.
Open the deep dive - 06 20 min
Request Flows End to End
Interviewers want to hear the path a request takes. Know the read, write, async, and failure flows and what each layer contributes.
Open the deep dive