It's okay NOT to check Slack all the time or respond immediately if you are focusing on something else.
Always be careful not to disturb someone so they can have a uninterrupted time for focused work (mainly when offline).
When you're in a creative mood, it's always better to share your ideas asynchronously (not asking for immediate feedback) in Notion with relevant people marked.
In case of emergency (e.g. the website is down) contact the right person ASAP (SMS, voice call, whatever..). It is highly appreciated also outside of the standard working time.
Report low priority bugs in the ‣, don't discuss on Slack.
For most of us, a sense of deep joy and accomplishment is possible when we experience flow, or focused work, and when we leave the workday with a sense of accomplishment.
The goal of these rules is to be less distracted and have more focused time for work and get it done quicker and better.
Do you need something from somebody to be able to continue your work? Maybe a decision, permission, question, etc?
If you think it is really important, use Slack over the face-to-face interaction to reach the target person. Don't expect immediate answer. Target person may have a focus time.
If you find a bug, it usually doesn't have to be solved immediately, so don't use Slack to report it. Instead, add it to the ‣.
If it is a crucial error, like service outage, alarm the proper person ASAP.