Since I started working in IT (many years ago) I have changed many companies.
I noticed that eventually the less I work the more I'm paid!

The matter is that IT jobs need certain degree of creativity - and it is not something well aligned with overworking. Doing bugs on weekends to fix them on workday nights is silly strategy. Managers who don't understand this - just ruin their projects and companies.

It is OK to work hard - but to work for your own professional grow. One may participate in commercial project by day - and write games by nights. Or watch online courses. We need to diversify our knowledge and skills - and working 24 hours a day on the same project won't help diversification!

You've probably seen this image before, but this is what 100% code coverage can look like:

It even passes all tests.

This is what will happen when you make high code coverage a strict requirement for developers.

An important reflection on the topic of online courses. While buying online course, you are not buying just the knowledge (it's available online for free in scattered, distributed, fuzzy, ambiguous forms). When buying (a good) online course you are buying knowledge that is curated, systematized and delivered in an interesting, easily digestible way (a system).

I'm entering the back half of my career and once I hit manager I realized that the skills I'd need for what's next were different than the skills that got me here.

I see two paths ahead for me: continue to grow as a business leader and work on my communications, management, and leadership skills or embrace some things inside me and become some flavor of teacher, helping other people learn and grow.

Both paths rely on written and verbal communication as well as an investment in people, and so I've been striving to write and speak more.

I'm going to continue to do this and get better at communicating technical matters in an accessible way.

Another idea: use single theme file and just toggle a global class name…

button.addEventListener('click', () => {
    document.body.classList.toggle('dark');
    localStorage.setItem('theme', document.body.classList.contains('dark') ? 'dark' : 'light');
});

if (localStorage.getItem('theme') === 'dark') {
    document.body.classList.add('dark');
}

/* Light mode */
body {
  background: #fff;
  color: #000;
}

/* Dark mode */
body.dark {
  background: #000;
  color: #fff;
}