Hi, jakearmitage. As a senior engineer that was able to get jobs/visa sponsorship abroad more than once I feel I can give you the following pieces of advice:

- Start with what kind of job you would love to have. Do you want to work for a blockchain startup? maybe a gaming one? Or fintech? It may be something you never did, don't limit yourself.

- If you don't have a Github project related to what you want to do, create one. Put a lot of emphasis on the README of the project and on code quality.

- Read a relevant book before starting looking for the job. That alone will give you a lot of stuff to talk about and it's going to be really fresh in your mind. People that read books have much more chances of standing out.

- Create 2 or 3 generic CVs and do customize them when applying for a job. I used to customize mainly the top paragraph(s) of the CV I use to introduce myself. Describe your skills and interests from the perspective of that particular job.

- Regarding CV style, I'd prefer a sober and minimalistic one. Google "best fonts for CVs 2020" and pick up one you like.

- Highlight keywords so it's much easier to understand your skills at first glance.

- Don't just list technologies but also explain in a higher level what you have achieved.

- Nowadays there are ML-based tools that analyze and even discard your CV before a human takes a look at it. Glassdoor had some time ago a CV analyzer that literally gave me hints that allowed me landing a job, after simply changing a bit its wording my CV got much more visibility. Find some of those tools and give them a try, if the feedback you get is reasonable edit your CV accordingly and see what happens.

- Have a lot of interviews! If it's difficult for you to get them (which I doubt if you are a principal engineer already), apply for jobs that you would just take in an emergency situation and sit those interviews. At some point I was having like 2-3 interviews a day. That helped me be sharp on selling myself after some weeks and that is crucial!

And that would be it, I hope this helps. Good luck with your search!