When I talk about speed in software, I don't mean runtime performance or benchmarks. I mean development velocity: how rapidly a system can be changed over time.

It's about how fast you can find out whether a change was a mistake.

In a lot of cases I think developers first learn they're "senior" when they get asked to start giving technical interviews. One day you're chasing bugs in a debugger and the next day someone's life, or at least the next bit of their professional life, is in your hands. This isn't what most developers aspire to. I certainly never did.

It can be awkward and uncomfortable, and nobody will train you for it. Most people probably just mimic what's happened to them, scars included.

But this is a good problem to have. It's an opportunity, but not one we always feel prepared for.

Maslow's hierarchy of needs is the Psych 101 version of how people's needs change as their circumstances do. A person on fire doesn't need more close friends, they need a bucket of water.

Similarly, not all development projects have the same needs at the same time.

In practice these needs stack, and you cannot skip the lower ones.

• Builds That Work
• Local Execution & Fast Feedback
• Tests That Tell the Truth
• Humane Feedback
• Smooth Changes

This one time I had a very high-profile deployment.

On our side: a bunch of developers in jeans and t-shirts.
On their side: suits. Lots of suits. Some even dialed in over video, back when that was still novel.

I was the team lead on the development side. The devops team had run through all the usual pre-deployment. Then it was time to press the big Deploy button.

Nothing happened.