Yes, you frequently can tell. There appears to be a number of people doing some form of automation with different degrees of success. Even though it's a clever use of software and when you're hiring for a software engineer it should be promising, it gets annoying and you tend to discard it. I wouldn't suggest attempting it unless you can do it extremely well if it's fully automated, or use it to help simplify the process, but still complete the last steps manually.

We've had a tendency now to introduce a request for a simple bit of information in the job posting as a sort of captcha to filter out automated spamming of applications.