Is it software, or more specifically a SaaS? In that case you might be out of luck, since most parts of the world don't recognize patents on software, apart from the US of course.

When your backend is server-side and doing something non-trivial, there is no copying without starting from scratch. Plus it's inner workings might be covered as trade secrets.

Generally, there is little to no value in ideas. Execution is what matters. Big players move slow, so that shouldn't be your biggest worry.