Recently, I integrated Google OAuth login functionality into a project and encountered numerous pitfalls from configuration to deployment. I’ve organized my experience into this article, hoping it will help other developers facing similar challenges. 🎯 Project Background 📋 Complete Configuration Process Step 1: Detailed Configuration in Google Cloud Console This is the first and most…

Tired of users spamming buttons and causing duplicate submissions—like 5 identical orders cluttering your database or 2 AM emergency rollbacks? This guide breaks down how to build a full anti-duplicate system with Spring Boot, from simple local locks for single servers to Redis distributed locks for clusters. Packed with practical code snippets, pitfall warnings, and…

This article provides a detailed solution to the “com.mongodb.MongoSocketOpenException: Connection refused” error that occurs when starting a Spring Boot project—even without any MongoDB configuration. It explains why the mongodb-driver-sync dependency triggers auto-configuration and offers two methods to disable MongoAutoConfiguration, helping developers quickly troubleshoot similar issues. 1. Background & Environment Overview To meet business requirements, a…

Wondering why Python lists can resize automatically? Why is append() fast but insert(0) slow? Starting from the C source code of CPython, this article disassembles core structures such as PyObject and PyListObject, analyzes underlying functions like list_resize() and list_append(), and completely reveals the static array essence of dynamic lists. It helps Python developers understand the…

An in-depth guide to Python circular imports, explaining why they occur, how they crash production systems, and how enterprise teams like Instagram detect and prevent them at scale using static analysis, runtime monitoring, and architectural refactoring. How a simple import statement can bring down your entire application—and why enterprise teams are investing millions in detection…

Learn how to create an interactive CLI application with Node.js for collecting and saving real estate sales data. Master user input prompts, data validation, JSON file handling, and error management to build practical and efficient CLI tools. Introduction Command Line Interfaces (CLIs) are powerful tools that allow users to interact with applications through text-based commands….

You might have seen some professional web apps like Google sheet, Figma or any other feature rich app. One thing that make these app’s user experience better is use of keyboard interaction. You can also added these keyboard interactions in your react app. In this article, I will try to explain how you can build…

In the world of web development, getting real-time data is crucial for building modern, interactive applications. While traditional APIs require you to constantly ask for new information, webhooks flip the script, pushing data to you the moment an event happens. This guide provides a comprehensive webhook example, walking you through the concepts, creation, and testing of…

Learn how to build intelligent AI agents with Flutter in 2025. This complete developer’s guide covers AI concepts, TensorFlow Lite, cloud AI services, and real-world use cases for cross-platform apps. The convergence of Artificial Intelligence and mobile development is rapidly reshaping how we interact with technology. Among the most exciting advancements in this space is…

Learn everything about HTTP Status Codes (200, 301, 404, 500) with clear explanations, categories, and examples. Perfect for web developers, backend engineers, API learners, and SEO specialists. If you have ever developed or used an API, you have undoubtedly encountered HTTP Status Codes. When you get responses like 200 OK or 404 Not Found, those are the three digit…