Hey everyone, There’s one design pattern that regularly shows up in Python code, for example in libraries like Pandas or Matplotlib. But most developers don’t even realize they’re using it. I’m talking about the Builder Pattern. This week’s video is all about this pattern. I cover: Why the Builder Pattern is so useful for building complex objects (like config files, HTML pages, or queries) When to use it and when not to A real Python example: building a small UI using a builder pattern How to...
13 days ago • 1 min read
Hey everyone, With AI agents and micro-SaaS tools popping up everywhere, it’s easy to think we’ll soon replace all traditional SaaS platforms by just vibe-coding our own. But that's an oversimplification. In my latest video, I break down: ✅ Why many SaaS platforms won’t disappear anytime soon ✅ Where AI-powered development is already transforming the landscape ✅ Which SaaS products are truly at risk, and which are stronger than ever Happy coding! Cheers, Arjan Do you enjoy my content on...
20 days ago • 1 min read
Hey everyone, I love it when I come up with a design that uses exactly the things I thought were a sign of bad design. In this week's video I show you how to build a clean Python SDK for a REST API. The idea was simple: create a reusable base model that handles all the CRUD operations so you can just write User.find() and user.save(), without duplicating logic all over your codebase. Sounds great, right? Well, after recording the video, I realized something: not all APIs will have all CRUD...
27 days ago • 1 min read
Hey everyone, Python’s flexibility is great, but if you're working on a larger project it becomes hard to make sure not everything depends on everything else. There is a way to avoid that trap, and that's by using abstractions. Unfortunately, I often see production code with way too much coupling that can be easily improved by relying on abstractions. This week’s video shows simple abstractions using Callable, ABC, and Protocol. You’ll learn how to: Reduce unnecessary imports Decouple your...
about 1 month ago • 1 min read
Hey everyone, I was reviewing some of the projects I’ve worked on over the past year, and I noticed something interesting: I almost never use Python’s @dataclass anymore. Not because it’s bad. In fact, dataclasses are still a great feature of the language. But as my projects have grown more complex, especially with tools like FastAPI, Pydantic, and SQLAlchemy, I’ve found that dataclasses just… don’t fit the way I design software anymore. In my latest video, I dive into this in detail. You’ll...
about 1 month ago • 1 min read
Hi there, You’ve probably heard that serverless is the easiest way to deploy code to the cloud. And on the surface, it is. With Google Cloud Functions, you can literally deploy a simple Python function like this: def hello(request): return "Hello from Cloud!" A few lines of code. No servers. No infrastructure. But... there are quite a few limitations: No FastAPI or async support One route per function requirements.txt only, no pyproject.toml Cold starts for large dependencies No custom...
about 2 months ago • 1 min read
Hey there, Heard of MCP? It stands for Model Context Protocol: an open standard that lets AI models like Claude or ChatGPT connect to real tools and data. In my latest video, I explain what MCP actually is, and show a working example where Claude can search YouTube videos using MCP. In the video you’ll learn: Why AI models can’t just call your API How MCP bridges that gap Two ways to structure your MCP integration Happy coding! Cheers, Arjan # News Upcoming Python Documentary CultRepo...
about 2 months ago • 1 min read
Hi there, We all use def to define functions in Python. But did you know there are at least 7 other ways to do it? Some of them are useful. Some are questionable. And the last one is so ridiculous, it might crash your interpreter. In this week’s video, I walk through each method, explain how it works, why you should use it (or not), and what it teaches us about how Python works under the hood. This was a really interesting topic to explore. I learned a lot from it and I hope you will too....
2 months ago • 2 min read
Hi there, Functional programming in Python can be elegant… but not always. ⚠️ In this week’s video, I walk through four common scenarios where replacing for loops with map() and filter() actually leads to worse code. Not just less readable—but also harder to debug, more error-prone, and sometimes even misleading. We’ll dive into: Exception handling that becomes a mess inside a lambda Side effects (like writing to files) that violate functional principles Nested logic that turns into...
2 months ago • 1 min read