I Trained My Own LLM from Scratch in 2025: What That Viral HN Tutorial Doesn't Tell You About the Real Cost

I Trained My Own LLM from Scratch in 2025: What That Viral HN Tutorial Doesn't Tell You About the Real Cost I was scrolling HN on a Tuesday night when I saw the post: "Train Your Own LLM from Scratch" , 241 points, 87 comments, and an energy in the thread I recognized immediately — the same one from "I built my own email server" or "I replaced Docker with bash scripts" threads. A mix of genuine technical enthusiasm and collective wishful thinking. I saved it. Two days later I opened it, cloned t