If you write a solution to something at work, then the company most likely holds ownership with whatever license they have.

However if you rewrite that solution in your spare time, into a package that solves the same problem but different then replace (with permission to) the original implementation with the new one..

Can said company then claim ownership on your package?

Similar situation for me.
We use opensource products as much as we can at my company and also contribute to them. Still my contract states that projects started at work belong to the company. Since we want sub projects to be opensource if it makes sense I start a public repo at home on github, setup a minimal readme, write some lines of code and set the license to something open. Now we can clone and start implementing at work. Managers are fine with it, they just don't want to change the contractm

Look in your contract. Might be that side projects are company property as well, even if done in your spare time

@epse yeah.

If the work serves the employer & the work is covered within your employment terms.
Since my position is software developer with no scope on language nor purpose..

Kinda tough luck lmfao.