These sound like two different kind of posts. Either way, make sure the canonical location is some place that you or your employer (whoever owns the content) have control over.
I'd suggest:
- Post your personal stuff on your own domain.
- Post your Google Cloud stuff on the company blog.
- Syndicate / cross post to Medium, LinkedIn, Twitter, wherever etc. if one or both make sense for the topic.
- You don't need to cross post the whole post if the platform doesn’t warrant it (lots of eyeballs, but hostile to the content-publisher, i.e. Facebook). You can put 2 paragraphs and a link to "read more on xyzblog". You're mostly using these services for discovery. In general, treat platforms you don't control as discovery-only.
- Encourage and enable readers to subscribe and engage directly at the canonical location (if practical), and not on the edges, as long as that doesn’t create a poor experience for them.
- If you find that more people want to engage / or the conversation is higher-quality at one of the distribution points (say HackerNews, vs the comments section of your blog), then provide a link to there from the canonical location and encourage conversation there.
(edit: Formatting)