If you are a HN user, don't multitask. Use your window manager's virtual desktops/tags. Don't switch between windows with different tasks in the _same_ desktop. Switch into another full task in the next vd/pane and go back later.

Use exclusively the vds with windows from the assigned task, I mean, if you need to operate with files in the 2nd desktop, just open the file manager windows there and leave out the other vds "untainted".

This way you'll focus better even if you have to "multitask". For example, in your 1st vd you have a web browser and in your 2nd vd, your editor/IDE for the web, and the 3rd one you would have some IM/chat/mail tools.

Kill all notifications, set an schedule to read mail/messages, for example every 20 minutes. Any true urgency/emergency won't be messaged, but done with an actual phone call.

And, finally, for web browsing, open four tabs as max, you won't need many more, even for documentation.

Addendum: In Unix/Linux most task can be scheduled thru Cron or pooled offline/online such as mail and well, this may sound old, but usenet news, a lot programming newsgroups are still alive.

You can set an script to download/upload/update/post mails/news/repos automatically in batches so you don't have to be always online. I mean, with that system you can write emails and news posts offline when you want and then a script would do these chores hourly/daily in a breeze.

News over RSS (a lot of good news site will have the full content in the RSS feed) will help in order to kill FOMO, as you can schedule them too (and read them offline).