Design for the four year old phone
5 min read
I keep an old phone in my desk drawer. It has a cracked corner, a battery that gives up at thirty percent, and it is the most useful design tool I own.
Everything feels fast on the machine you build on. It has the newest chip, a wired connection and nothing else running. The people using your product have none of that.
What the old phone finds
Within five minutes of using a new build on it, I usually find the same handful of problems.
- A hero animation that drops frames because it blurs a large area every frame.
- A layout that jumps when a web font arrives late.
- A tap target that is fine with a mouse and impossible with a thumb.
- A page that downloads a whole charting library to draw one line.
None of these show up in a design review. All of them show up in reviews on the app store.
Make it a habit
Open every pull request on the old phone before you merge it. Not in a simulator, on the real thing, on the train if you can. It takes two minutes and it will change what you build.
If it feels good on the worst device your customers use, it will feel great on the best one.