I’ve been in this situation when I was a junior engineer and found it really frustrating. I’d literally done more work in a week than the “senior” had done in their time at the company. They had shipped one change (a migration) and then nothing for 8 months.
Why should I stay at your company as a junior engineer if the people I’m teaching things to are senior to me?
It devalues seniority and the general appearance of meritocracy in your organization to keep this person at senior. If you really want to be nice, give them the title and compensation that is appropriate for them. If you can’t do that, the right thing to do is to politely say it’s not a great fit for the role and let them go.
I actually think something like this could be a positive change. Anecdotally, I know many millennials who have found Instagram Reels uncomfortably addictive. My Gen Z friends and family say TikTok has an even “better” algorithm.
At a certain point, these platforms become like (no-cost) slot machines and take away a lot of our motivation and productivity as a society. Maybe this specific piece of legislation isn’t ideal but we should probably have some sort of regulation that treats addictive content along the lines of something similarly addictive like gambling. Gambling is obviously a more severe addiction for gambling addicts but social media addiction is much more common.
Does it go against the first amendment? No idea. However, we’re losing hours every day per social media addict to these algorithms and that’s a cost that I think we should take seriously as a society.
The best way is probably to ask them to show you that it’s working and explain how they know that’s the intended or correct behavior.
Another way would be to learn some technical details so you understand what they’re saying and doing instead of writing yourself off as non-technical.
A worse but doable way is to have someone with expertise check their work. That only makes sense if you don’t trust your developers which is a pretty bad situation.
Your question is weird because it’s sort of like asking “How do you know if a contractor is building a house properly when you don’t know anything about building houses?”