According the ECB[1] data on 24 Jan 2017 the exchange rate was 1 EUR = 1.0514 USD and today is 1 EUR = 1.1806 USD so we have:

    (1.1806-1.0748)/1.0748 = 0.0984 => 0.0984 * 100 = 9.84% 

How exactly did you manage to lose 30%?

[1] https://www.ecb.europa.eu/stats/policy_and_exchange_rates/eu...

Then take another time span, but the currency fluctuations are so large that it becomes the largest factor to how much you actually take home.

I definitely wouldn't want that.

(I misremembered which currency fell 30% against the Euro, it was the pound instead)

It would also suck for the company to have payroll costs increase 30% because one of their remote devs happens to live in another country :)

The company can always re-negotiate, but a 30% paycut might mean you can’t afford your rent or mortgage anymore.