Caching — Complete Guide
Everything you need to know about caching in system design: strategies, patterns, distributed caching, Redis, CDNs, and cache invalidation.
📚 Articles (10)
Cache-Aside Pattern: The Most Common Caching Strategy Explained
The cache-aside pattern (also known as lazy loading or lazy population) is the most widely used caching strategy in web applications. In this pattern, the ...
Cache Invalidation: Solving the Hardest Problem in Computer Science
Phil Karlton famously said, "There are only two hard things in Computer Science: cache invalidation and naming things." While the quote is often shared as ...
Cache Stampede: Understanding and Solving the Thundering Herd Problem
A cache stampede (also called the thundering herd problem or dog-pile effect) occurs when a heavily-accessed cache entry expires and many concurrent reques...
Caching Fundamentals: The Complete Guide to Faster Systems
Caching is one of the most powerful techniques in software engineering for improving application performance. At its core, caching stores copies of frequen...
CDN Caching: Accelerating Content Delivery at the Edge
A Content Delivery Network (CDN) is a globally distributed network of servers that caches content close to end users. When a user in Tokyo requests your we...
Distributed Caching: Scaling Cache Across Multiple Nodes
When a single cache server is no longer enough — because your dataset outgrows its memory, your request rate exceeds its throughput, or you need fault tole...
Cache Eviction Policies: LRU, LFU, FIFO, and Beyond
Every cache has a finite amount of memory. When the cache is full and a new entry needs to be stored, the system must decide which existing entry to remove...
Hot Keys: Detecting and Solving Cache Hotspot Problems
In any caching system, a small percentage of keys typically receive a disproportionate share of traffic. When this imbalance becomes extreme — a single key...
Redis: The Complete Guide to the World's Most Popular In-Memory Data Store
Redis (Remote Dictionary Server) is an open-source, in-memory data structure store used as a cache, database, message broker, and streaming engine. Created...
Write-Through vs Write-Back Caching: Consistency, Performance, and Trade-Offs
When your application writes data, how should the cache and database stay in sync? This is one of the most important decisions in cache architecture. The t...
❓ Frequently Asked Questions
What is caching in system design?
Caching stores frequently accessed data in fast storage (like memory) to reduce latency and database load. It's one of the most effective techniques for improving system performance.
What are the main caching strategies?
The main strategies are cache-aside (lazy loading), write-through (sync writes), write-back (async writes), and read-through. Each has different consistency vs performance trade-offs.