In a similar role and have peers in a similar role, a lot to unpack here:

No Micromanagement ≠ No Guidance or Collaboration

There is unfortunately a perception in startup engineering orgs that any meeting is a waste of time and that 100% of time should be spent coding. My personal KPI for eng teams is 85-90% of IC time is coding, 10-15% of the time is spent on standups or spontaneous collaboration sessions to figure out exactly what we are trying to build.

It is unclear how you are running the team (Agile / Waterfall / Agilefall / some other flavor) but it doesn't really matter. At the end of the day, your job as the team lead / CTO is to empower your team to get things done. Guidance around what and how to build it is not the same as micromanagement.

Micromanagement

- Asking an engineering every 30 mins where a given feature or task is at.

- Mandating that you review every line of code prior to pushing to production

Guidance and Technical Leadership

- Holding (optional) office hours at 11am everyday for engineers to hop on with any questions or discussion points

- Asking an IC to work on the solution to a problem for 4 hours then check in with what they have

Lack of Awareness of IC Work ≠ A Problem

You mentioned that you trust 3/4 of the team already - do you feel the need to track those individuals throughout the day or week? If one of them disappears for hours at a time, are you concerned, or do you believe they are working and will check in if they have issues?

Managers that have the concern of "what is someone doing all day" either do not trust that person to complete the tasks assigned to them and ask for help when needed (lack of trust) or believe that they are abusing their remote position and doing less work than they could be doing (bad actor). You may have very legitimate reasons for believing either of these things.

If you don't trust them, what can you do to build that trust?
If they are a bad actor, what can you do to confirm that they are a bad actor vs misinterpreting your goals and objectives for them?

The best way I have found is via a 1/1 every two weeks, with the following questions:

- Do you feel as though what is being asked of you is clear?

- Are you currently doing the work you want to be doing?

- What is harder than it should be?

The answers to these questions will likely confirm or deny your level of trust and whether the IC is a bad actor. Then you can figure out the appropriate next step.

Productivity Software ≠ Effectiveness

I would not recommend productivity tracking software or any "monitoring" software. This is your role - to make sure the team spends time on what is worth spending time on. Software will not be able to tell you whether the direction you are heading is the right direction, that is a judgement call.

There is an old communist joke "We pretend to work, they pretend to pay us". The analog here is, "We pretend to log JIRA hours/tickets, they pretend we are productive". You need to decide what level of effectiveness is appropriate for your team and drive towards that, whether that is new features, platform stability, security, etc. Not whether the team is superficially productive.

Team Size

-15 people is way too many people for anyone to effectively manage. You should be looking at 1/2 direct reports to help you manage those folks, but before you do that, you need to be able to tell them what to look for and how to manage the team. So while it may be overwhelming in the short term, I would recommend figuring out your system first, before hiring others to help you run it.