I have been advised as such by a friend if and when I go to passport control in Canada-
Summary: The less you say the better. You are attending a software technical conference. the end.
You are not "working" with or for it or anything that might sound like work. "volunteering" is work. If you hint that you might help out the reg desk, it is their job to get things evaluated by the labor dept that understands the labor market etc and that takes a minimum of 3 days. As long as you don't leave the country with a bag of money they don't care what you did at the conference.
My wife spoke at a technical conference in Montreal. That fact got her a round of questions, mostly "are you being paid to speak?" - I would avoid saying anything other than "attending."
If pressed for details, I would not lie.
I do know if this post-trump or this was always there and it doesn't matter as well. Has anybody have any experiences at passport control while going to attend/speak at conferences in Canada ?
I have put up for a travel bursary and from what has been shared with me, selection of talks does influence travel bursaries quite a bit.