Every design leader eventually gets asked the same question: “What’s the right designer-to-engineer ratio?” It sounds like a smart, strategic question. It’s measurable, clean, and looks great in a spreadsheet. I’ve given that answer plenty of times myself: 1:5 or smaller when a product is scaling, up to 1:10 as it matures. The numbers make sense on paper.

But the truth is ratios are just a planning tool, not a performance indicator. They’re useful when you’re building a business case or scoping a new product team. After that, they matter far less than how the team actually works together.

I’ve seen teams with ideal ratios struggle because the culture was misaligned. Designers felt siloed, engineers were sprinting ahead without context, and the “perfect” resourcing plan couldn’t save them. I’ve also seen small, lopsided teams outperform expectations because they had clarity, strong systems, and mutual respect.

Ratios can’t account for quality. They don’t measure trust, curiosity, or the ability to navigate ambiguity - all the things that make design valuable inside complex organizations.

At Zoox, for example, some of our internal tools teams run lean. A single designer might partner with 10+ engineers. It works because that designer is deeply embedded in the workflow, understands the users intimately, and has strong systems in place for feedback and iteration. The ratio looks uneven from the outside, but the collaboration is fluid and effective. 

There’s also a lot of hype now about flipping ratios thanks to AI tools: staffing more designers than engineers. It’s fun idea, and I’m sure some teams are working that way already. The reality for most teams, however, is that AI tools are impacting velocity for design AND engineering in parallel. So the net result is not a different ratio, but a higher throughput team. 

So when people ask about ratios now, I tell them: it’s less about math, more about metabolism. How quickly can your team learn, adapt, and align? That’s the real indicator of health.

Ratios help you get to the starting line But the culture and strong fundamentals are what wins.

So yes, start with a ratio if you need one. It’ll help with planning and headcount arguments. But once the team is running, stop optimizing for the numbers. Optimize for the chemistry.