I think something that could help is moving together rather than one-by-one. We could have a website where you can register as "ready to move from X to Y when N other people are", when the goal is reached everybody gets a notice it's time to move.

And if you don't want to code your own HMM it also has the best (AFAIK) HMM library out there (HiddenMarkovModels.jl).

Implement a linear regression or Bayes' theorem.

I wonder if there's correlations between tasks and languages, e.g. maybe R is better for bioinformatics tasks, python for webdev, C for CLIs, etc. I'd expect to see it because some languages are used more often in some tasks than others, but on the other hand LLMs can learn across languages and it's not clear if task-language use patterns are just historical or if the language is genuinely better at the task.