"One and two-way doors" is a nice way to phrase it. I use a similar heuristic to figure out where to spend more effort designing things upfront. For most web apps, the one-way door is usually going to be the database schema - data migrations are trickier to do once you have to deal with real data.
The other big class of "one-way" decisions are with regards to code that live in environments you don't control, e.g. mobile and desktop apps.
One tip I would offer is when building something new, you should try and delay making one-way decisions as long as you can, until you have a clearer picture of how things should work.
The other big class of "one-way" decisions are with regards to code that live in environments you don't control, e.g. mobile and desktop apps.
One tip I would offer is when building something new, you should try and delay making one-way decisions as long as you can, until you have a clearer picture of how things should work.