Veracrypt and use a hidden encrypted partition so you have plausible deniability. Remove the app after. If it’s encrypted it’ll be fine so long as it doesn’t look obvious.
I’ve never heard of border guards checking devices, ever… and definitely not randomly. If you’re paranoid the cloud is a safer option of course, as others have said. Backblaze is great for cost etc… but definitely encrypt before upload imo.
I personally refuse live coding sessions during interviews, including whiteboard programming. If they require this during an interview the company’s not for me.
Don’t mind code challenges where I have a timeframe and can submit. It’s not how you code normally so why should it be how you’re hired?