Many coding challenges are great drill work: but if you can, have your code read by someone else to ensure you're practicing how to write readable, maintainable code.

Leetcode solutions seem to be regularly "golfed" into being unreadable and intractable. Don't practice that!

At least in my experience, well-defined and functionally isolated coding challenges rarely happen at work, though.

Another skill you'll need to hone is listening to your userbase/business partners and translating what they're saying into actual specifications.

Doing this adequately is a prerequisite to success.

Doing this well (hearing what they need, separating the "need" from the "how", and being imaginative in what a clean implementation would look like) can both reduce what work is needed now, and set up future success to be more likely.