architecture How Distributed Locks Actually Work (And Why They’re Harder Than They Look) josedacruz, August 5, 2026August 5, 2026 TL;DR: A distributed lock stops two servers from doing the same risky thing at the same time, like selling the last concert ticket twice. The tricky part isn’t getting the lock — it’s what happens if the worker holding it crashes, freezes, or runs slower than expected. Get the timeout… Continue Reading
architecture How Instagram-Style Feeds Work: Fan-Out on Write vs. Fan-Out on Read josedacruz, August 2, 2026August 2, 2026 Imagine you’re on the backend team at a small photo-sharing app called Snapstream. Every user has a home feed: a scrolling list of photos from the people they follow, newest first. For your first 10,000 users, this is easy. For your next 10 million, it turns into one of the… Continue Reading
Systems Thinking Thinking in Systems – An Introduction josedacruz, April 20, 2025April 20, 2025 Welcome to a practical and eye-opening introduction to Thinking in Systems — a powerful way to understand and navigate complexity in your daily life, work, and projects. In this video, you’ll discover:✅ What a system really is (it’s more than just tech)✅ The 3 essential parts of any system: Elements,… Continue Reading