Backend

Python is often criticized for being “slow” or “single-threaded” due to the Global Interpreter Lock (GIL). However, for many modern applications—from data processing pipelines to high-traffic web servers—concurrency is not just an option; it is a necessity. Understanding when to use threading versus multiprocessing is the hallmark of a senior Python developer. This guide dives deep into the mechanics of Python concurrency, explores the limitations of the GIL, and provides practical patterns for maximizing performance. ...

In the era of social media and character limits, URL shorteners like Bitly and TinyURL have become essential infrastructure. While the core functionality—mapping a long URL to a short one—seems simple, building a system that can handle billions of requests with millisecond latency and 99.99% availability is a classic system design challenge. In this post, we will walk through the architectural blueprint of a scalable, resilient URL shortener. 1. Requirements and Goals Before diving into the architecture, we must define our constraints. ...

Elasticsearch has become the de-facto standard for search and analytics in modern applications. Whether you’re building a search bar for your product, analyzing logs at scale, or powering real-time dashboards, Elasticsearch is likely on your shortlist. This “zero to hero” guide is designed to take you from no prior knowledge to a solid, practical understanding of how Elasticsearch works and how to use it effectively in real-world systems. Along the way, you’ll get code examples, architectural explanations, and curated learning resources. ...

Batching API requests is a proven technique to improve throughput, reduce overhead, and tame the N+1 request problem across web and mobile apps. But batching is more than “combine a few calls into one.” To do it well you need to consider protocol details, error semantics, idempotency, observability, rate limiting, and more. This article explains how batching works, when to use it, and how to design and implement robust batch endpoints with real code examples. ...

Introduction Cross-Origin Resource Sharing (CORS) is one of the most misunderstood parts of modern web development. It sits at the intersection of browsers, HTTP, and security, and when it goes wrong you often see opaque errors like “CORS policy: No ‘Access-Control-Allow-Origin’ header…”. This guide takes you from zero to hero: you’ll learn the mental model behind CORS, how the browser enforces it, how to configure servers correctly across popular stacks, how to optimize performance, and how to avoid common security pitfalls. ...