The majority of verification starts on the internet yes. That's how they did mine and lots of others' that I know. The more additional documents you submit to show your employment, the less likely they are to contact your employer for verification. I submitted:
- Reference letter
- Promotion letter
- Contract extracts for some jobs
- Manager's business card for every job
- My LinkedIn and my managers' LinkedIn profiles
- Work visa copies (I worked in Dubai)
- Payslips
- Salary deposits into my account
I got my PPR in about 80 days (FSW Outland). Regardless of my security check, I believe this help speed up my eligibility verification, but it could always be something else. Which is why I try to tell people to provide similar types of documents (only if they can).