In many countries, there exist excellent private and public pension funds. However, those are often designed on the assumption that people will work with the same employer for decades, and certainly within the same country. If I am working in many different countries throughout my life, I may end up with 5–10 pension that are all tiny, all from different countries, with likely a high overhead for administration and international money transfer. Therefore, I'm considering to complement it with a private pension or life annuity insurance.
Are there any specific private pensions or life annuities geared to people who may live and earn income in a large number of different countries throughout their life? Things to consider would be to avoid double taxation and minimise costs for international money transfer, both when paying into the annuity and during the payout period.
(Specifically to my situation: passport from The Netherlands, pensions so far from public employers in Sweden and Canada, very likely from other countries later, probably still public employers (state, federal, or perhaps supranational))