The Constraint is a one-minute operating note, written by Justin Guerra. One useful idea per issue, from real work.

Who's writing this. I'm a co-founder of Chrono, an AI system that watches a business's data and flags what to focus on. I'm also part of the team behind Goblin Gear, a gym-gear brand, where I run the finance and strategy side. I studied business, finance, and statistics in college and picked up some equity-research experience early on, which is roughly where the numbers habit comes from. But the reason to read this is the work now: most of what I write comes from two seats at once, helping run a real business, and building the software that reads businesses like it.

What this is. One idea, in about a minute, every week. Four kinds of thing: a finding from running the business, one lesson from a book worth reading, a decision-making framework I actually use, and an honest field note from building. That's the whole menu. No roundups, no news, no ten-point lists.

How I write it. Plain, and grounded in something real, a number, a decision, a mistake. I only write what I'm actually living, and I never tell you what to do. I tell you what I saw and what it taught me. If it doesn't help you run your business better, it doesn't go in.

Why I write it. Two reasons, honestly. Writing something down and having to defend it makes me a sharper operator. And the best operators I know share what they're learning instead of hoarding it, so I'm trying to do the same.

If you run a business and want to think a little sharper each week, subscribe.

Find the constraint.

In whatever you do, expect friction.