How much cumulative Canadian work experience do I need for a job-offer-based nomination?

The general figure being cited for the new stream is at least 1 year of cumulative, paid work experience in the same occupation as the job offer, earned within the last 5 years, so at 8 months you'd likely be short unless you have earlier relevant experience from within that 5-year window that adds up to 12+ months combined. Worth adding up ALL qualifying experience, not just your most recent job. General information from my own experience, not legal advice — for anything specific to your file, a licensed RCIC or immigration lawyer can look at your actual documents.