Programming articles from Sudo engineers: Java design patterns, Python, AI and data, and web development, with runnable code examples.
The line new EmailSender() sits deep inside a business class and looks harmless, until the day a customer asks for SMS, then Zalo, and your test suite can't run without an SMTP server. Factory Method...
The previous article in this series used Scrapy, a framework that ships with its own scheduler and concurrency limits. But many smaller jobs, such as calling a few hundred internal APIs or checking th...
The requests plus BeautifulSoup loop from the previous article on crawling with requests, BeautifulSoup and robots.txt is enough for a few dozen pages. Once you need thousands of pages, you end up wri...
Every enterprise Java codebase has a few objects that "should exist only once": a configuration holder, a connection pool, a product catalog cache, a logger. The Singleton pattern is the classic way t...
Almost every data project eventually needs numbers that the source does not offer through an API: a competitor's price list, a public product catalog, an exchange-rate table. That is when crawling dat...
In a data or AI project, the thing that costs the most hours is usually not the algorithm but the question "why does it work on my machine?". One notebook uses one version of numpy, a teammate's machi...
Most enterprise Java systems start out clean and gradually get tangled: one OrderService class calculates prices, writes to the database, and sends email; adding a promotion type means reopening a met...
