Thanks for bringing this up @nizar ! It’s definitely always good to discuss these things - even on points where there might be disagreements, it’s better if we know and talk about it.
…which isn’t bad for a minimum worldwide salary? Especially considering the fact that this is based on 30h/week, with all overtime paid - even taking into account the fact that OpenCraft hours are all “real” work (ie doesn’t include breaks, which are counted in time spent in an office for example), the expectation in most of the development companies I’ve worked for is to put in at least 40-50h/week - and sometimes much more than that. The way we work allows to get a better work-life balance by working less if we want to (and we encourage it), but that’s something to keep in mind while comparing salaries.
I can see your point though, when starting with a very low rate it can take a lot of time to recover from it – that’s actually why we have the minimum salary. It can make sense to increase the minimum rate a bit further, to reduce the spread - it contributes to reducing disparities within the team, and within the world.
I looked at what we can reasonably do here – and I’ll increase the minimum rate to 35 euros/h. This is already a good rate on international remote jobs, which allows to live comfortably almost anywhere in the world. I’ll apply it when we do the round of increases in January, and include the raises received since joining on top of it, retroactively. 
Concretely, this means that if you have joined with a rate inferior to 35 euros/h, you’ll get a raise to a rate of 35 euros/h + the % raises that have been applied to your rate since you joined - for those who have joined after 2016, that’s 35*(1.1)^n - with ‘n’ being the number of full calendar years since you joined.
Note that this is the rate for a single hour of support, and isn’t necessarily representative of the rate for larger volume of work, especially for long-standing clients.
If we did this, as mentioned by others, it wouldn’t take long for everyone to figure out the maximum rate that can be asked, and everyone would ask that – ie we would end up with a unique rate.
True, this is a loophole that hasn’t been thought through. People returning to OpenCraft have had the occasion to figure out the range that can be asked, so allowing people who return to set a new rate gives them an unfair advantage. We probably need a better rule here to avoid that - maybe based on the previous rate, with only a percentage of the raises applied for the time the person wasn’t at OpenCraft would make sense. To still reflect the additional experience gained in other jobs, but closing the loophole and keeping it more advantageous to stay rather than leave. Some people might choose not to return because of this, but I’d rather prioritize keeping things fair for the people in the team rather than incentivize leaving it.
That’s a great idea – it would be good to have that, it would help taking a more informed decision for people joining, and reducing surprises. It might be a bit tricky to figure out all the specifics for each person, like the applicable tax rate, but those could be fields to set by the applicant?
That’s a good point - it’s a bit unfair currently for people joining early in the year. The percentage based on the time worked during the first year works for me. 
I’ll apply that on the next round of raises, in January, to people who have joined this year.
With the switch to trial projects, people will be joining the company immediately, so they will get the minimum rate as soon as they start. For the initial test phase, given that we don’t know yet if the candidate does a good job, it doesn’t seem unfair to me to pay them what they asked, and to raise the rate once we consider the person a proper team member.
If by career growth you mean getting a raise when changing positions - it is meant to be covered by the yearly raise. Even when switching jobs within a company, it’s rare to get 10% out of it - especially to get this on a yearly basis. These are pretty fat raises!
And there isn’t even a need to ask for them or negotiate them. It’s not that we forbid negotiations & asking for raises – it’s more like asking automatically for everyone, and giving the highest raise we can provide to everyone. The alternative, standard individual negotiation, wouldn’t allow to ask for more, it would just be a different distribution - with more given to those who negotiate, and less to those who don’t, or not well. Plus all the side effects on politics and competition that we have already discussed…