Ask HN: How do you share and update the app specifications with your team?

I am a front-end engineer. I have been working as a front-end engineer for mobile apps for 10 years.

I have developed various apps for several clients. One of the problems I face every time the application specifications are not fully expected or written in various places and are not up-to-date.

These days, many clients write screen design and screen transitions in Figma and more detailed behavior specifications in Notion. However, often the Figma is out of date, or the content in the Notion does not match the Figma, and in the end I have to ask the product manager via Slack or Zoom.

Have you ever encountered these problems? How did you solve them? Any sophisticated ways to share app specs or keep them up-to-date?