"I need some way to know how hard the engineers are working"
You get what you measure.
If you really want to know how many hours your engineers are sitting in front of a keyboard and screen in your office, you can find a way to get that information. If you tie compensation to that figure, your engineers will definitely give you plenty of butt-in-seat time (or quit).
If you do not have other ways to evaluate their output, though, you may not get much more than that. They might just read Hacker News all day. You can put in measures to block Hacker News, but at that point you have an escalating battle of not trusting your employees and putting in increasingly draconian measures until you have created a call center environment where your employees have a set number of minutes a day they are allowed to go to the bathroom, and have to get really good at holding it otherwise.
How many good developers do you think will be left at that point?
I did jump over some points along the continuum there. But the point is, if you do not have some level of trust in the relationship with your developers, you're probably screwed anyways.
You get what you measure.
If you really want to know how many hours your engineers are sitting in front of a keyboard and screen in your office, you can find a way to get that information. If you tie compensation to that figure, your engineers will definitely give you plenty of butt-in-seat time (or quit).
If you do not have other ways to evaluate their output, though, you may not get much more than that. They might just read Hacker News all day. You can put in measures to block Hacker News, but at that point you have an escalating battle of not trusting your employees and putting in increasingly draconian measures until you have created a call center environment where your employees have a set number of minutes a day they are allowed to go to the bathroom, and have to get really good at holding it otherwise.
How many good developers do you think will be left at that point?
I did jump over some points along the continuum there. But the point is, if you do not have some level of trust in the relationship with your developers, you're probably screwed anyways.