You can still travel and work across europe for now, as long as a brexit deal is reached. You have a fine startup scene in the baltic, crazy startup in Paris and Berlin (tbh, it'll be easier in germany right now), you have really professinnal, interesting companies in the Netherlands, Lille or Hambourg if your thing is devops/non-web dev. With the AI4EU project, you can also land a job building tools for machine learning[1]. We have plenty of oportunities here.

[1] Honestly, it'll mostly be integrating different ML opensource solutions together and maybe some FOSS contribution from what i've seen.

Well Captain Nemo, I have heard this part of the story before...

To the seas!