Performance Optimization

Performance Optimization

How to diagnose and fix slow canvas apps: delegation limits, load-time strategy, formula caching, and the Monitor tool.

What Are Database Compression Techniques and Why Do They Matter?

Database compression techniques shrink the physical size of stored data by removing redundancy — through methods like dictionary encoding, run-length encoding,…

What are Cache-Oblivious Algorithms?

A cache-oblivious algorithm is designed to use the memory hierarchy — CPU caches, RAM, and disk — efficiently without knowing any cache size or block size as a…

What Makes a Data Structure Cache-Friendly?

A cache-friendly data structure maximizes spatial and temporal locality — storing related data contiguously in memory so that a CPU cache line fetched for one…

What is Lazy Initialization in OOP?

Lazy initialization is the technique of deferring the creation of an expensive object or the computation of a value until the exact moment it is first actually…

What is Object Pooling?

Object pooling is a technique where a fixed set of expensive-to-create objects is created once, kept in a reusable pool, and handed out and returned repeatedly…

Move Semantics vs Copy Semantics

Copy semantics duplicates an object’s resources so the source and destination each own independent data, while move semantics transfers ownership of a source o…

What is a Move Constructor?

A move constructor is a special constructor (in C++, T(T&& other)) that builds a new object by transferring ownership of an existing rvalue object’s internal r…

What is the Rule of Five in C++?

The Rule of Five extends the Rule of Three for modern C++ by stating that a resource-owning class should typically define all five special member functions tog…

What is Shortest-Job-First (SJF) Scheduling?

Shortest-Job-First (SJF) is a scheduling algorithm that always dispatches the ready process with the smallest total CPU burst time next, which provably minimiz…

How Would You Design a Real-Time Leaderboard?

A real-time leaderboard ranks a large, constantly updating set of scores and answers “what is this player’s rank” and “who are the top N” in near-constant time…

What is a Bloom Filter and When Would You Use One?

A Bloom filter is a space-efficient probabilistic data structure that tells you whether an element is definitely not in a set or possibly in a set, trading a s…

What is a Count-Min Sketch and How Does It Estimate Frequencies?

A Count-Min Sketch is a probabilistic data structure that estimates how many times each item has appeared in a stream using a small, fixed amount of memory, at…

What is HyperLogLog and How Does It Count Distinct Elements?

HyperLogLog is a probabilistic algorithm that estimates the number of distinct elements (cardinality) in a massive dataset using only a few kilobytes of memory…

What Are Cache Eviction Policies?

A cache eviction policy is the rule a fixed-size cache uses to decide which entry to remove once it is full and a new item needs to be stored, and the choice o…

What Are Cache Invalidation Strategies?

Cache invalidation strategies are the mechanisms a system uses to remove or refresh stale cached data once the underlying source of truth changes, and the two…

What is the Cache-Aside Pattern?

The cache-aside pattern (also called lazy loading) puts the application in charge of the cache: on a read the app checks the cache first and only loads from th…

What Are Edge Caching Strategies?

Edge caching stores copies of responses at CDN points of presence physically close to users, so most requests are served from a nearby edge node instead of rou…

What is a Single-Page Application?

A single-page application (SPA) loads one HTML shell up front and then rewrites the page in the browser with JavaScript, fetching only data — not full new page…

What is Lazy Loading?

Lazy loading is the technique of deferring the loading of a resource — an image, a script chunk, or a component — until it is actually needed, instead of loadi…

What are HTTP Caching Headers?

HTTP caching headers are response headers such as Cache-Control, ETag, and Last-Modified that tell browsers and intermediate caches how long a response can be…

What Is Event Delegation and Why Use It?

Event delegation is the pattern of attaching a single event listener to a common ancestor element instead of separate listeners on every individual child, rely…

WeakMap vs WeakSet: What Is the Difference?

A WeakMap stores key-value pairs where the keys must be objects held only weakly, so entries are automatically garbage-collected once nothing else references t…

useMemo vs useCallback: What Is the Difference?

useMemo memoizes the returned value of an expensive computation so it is only recalculated when its dependencies change, while useCallback memoizes the functio…

What Are the Size Limits of Web Storage Mechanisms?

Cookies are limited to roughly 4KB per cookie (and a per-domain count cap around 50-180 depending on the browser), localStorage and sessionStorage typically ca…