These things are rarely binary. In that there's no one size fits all solution. It comes down to the culture of the company and how they communicate and then how

These things are rarely binary. In that there's no one size fits all solution. It comes down to the culture of the company and how they communicate and then how the technology evolved based on their needs. So if you have an engineering org which practices high bandwidth communication there might be a drive to keep that up by coordinating a meeting once a week by nominating one person from the team to go provide updates and learn about what else is happening. You may also explicitly establish an architecture team that has oversight and tries to ensure everyone's aligned on direction. But mostly if you at least have some shared place where you explicitly communicate the creation of new services or design development then it allows you to avoid some of the issues you're talking about. The other thing is having a way to discover APIs and services so you can go check if something exists before building it. In many cases teams do still build a variant themselves because they need something slightly different and thats ok if they're willing to support it.