architecture Immutability – architecture series 1/7 josedacruz, March 2, 2026March 2, 2026 Most developers learn immutability as a coding concept… but stop there. That’s a mistake. In this video, you’ll discover why immutability isn’t just about objects in code — it’s a core architectural principle that scales across your entire system: We break down the 3 levels of immutability and show how… Continue Reading
architecture Immutability: The One Concept That Eliminates Hidden Bugs josedacruz, February 21, 2026February 21, 2026 Immutability is one of the most important concepts in modern software engineering — and one of the most misunderstood. In this video, we break down what mutability and immutability really mean, why mutation causes hidden bugs, and how immutable patterns make your code safer, easier to debug, and more scalable…. Continue Reading
artificial-intelligence How TensorFlow Really Works: Tensors, Shapes & Real Business Examples josedacruz, December 13, 2025December 13, 2025 TensorFlow isn’t only “neural networks” — at the beginning, it’s a powerful tensor math engine. In this video, you’ll learn what TensorFlow is, what a Tensor is, and the key concepts that make everything work: rank, shape, dtype, indexing/slicing, reshaping, broadcasting, and aggregation (reduce operations). Then we make it practical… Continue Reading
artificial-intelligence ML Essentials Explained: Functions, Loss, and Gradient Descent + Live Demos (Linear Regression & K-means) josedacruz, December 12, 2025December 12, 2025 Unlock the core ideas that power modern Machine Learning. In this video, we break down ML’s foundation: function approximation, supervised vs. unsupervised learning, and the optimization engine behind nearly every model—Loss Functions and Gradient Descent. To make the concepts real, we walk through two hands-on demos using NumPy and Matplotlib:… Continue Reading
architecture Idempotency in APIs: How to Handle Retries Safely (Python Example) josedacruz, December 10, 2025December 10, 2025 What happens if a user clicks “Pay Now” twice? Or if a network timeout causes a request to retry automatically? Without Idempotency, your API might process that payment twice. In this video, we explore the concept of Idempotency in API design—a critical property that ensures performing an operation multiple times… Continue Reading
architecture LLM Architecture: Internal Mechanisms, RLHF, and Token Prediction Explained josedacruz, December 10, 2025December 10, 2025 Continue Reading
artificial-intelligence Ep2: I Built a Free AI Roast Generator with LangChain 2025! Learn PromptTemplate + LCEL josedacruz, December 2, 2025December 2, 2025 In this video, you’ll learn how to build a fun and practical AI project: a personalized Tweet/Roast Generator using LangChain 2025 and GitHub Models for free. This tutorial introduces PromptTemplate, ChatPromptTemplate, and the LCEL pipe operator, showing how these powerful components let you build clean, reusable AI pipelines with just… Continue Reading
artificial-intelligence Ep1: Build Your First FREE AI Email Generator! LangChain 2025 + GPT-4o-mini (No OpenAI Credits Needed) josedacruz, November 30, 2025November 30, 2025 In this video, you’ll learn how to install LangChain 2025, set up GitHub Models for completely free LLM usage, and make your very first AI call using GPT-4o-mini. This is the perfect starting point if you want to build real-world AI applications without paying for tokens or setting up complex… Continue Reading
architecture ETag in APIs — From First Principles to Code josedacruz, October 28, 2025October 28, 2025 Ever wondered what that mysterious “ETag” header in APIs really does? 🤔 In this video, we break down ETags from the ground up — what they are, why they exist, and how they make your APIs faster and safer! You’ll see how cache validation, optimistic concurrency, and retries all rely… Continue Reading
spring-boot Spring Boot Scheduler Made Easy | @Scheduled with Fixed Rate & Cron Examples josedacruz, September 27, 2025September 27, 2025 In this video José Cruz shows you how to use the Spring Boot Scheduler to run jobs on a schedule. You’ll see when to use it, when not to, and how to externalize timings with properties. We build a simple heartbeat job that runs every 5 seconds and explain fixedRate,… Continue Reading