Basic knowledge/practice of programming that you MUST know
Learn the knowledge until it makes sense for you. It is one of the technique while learning how to code. You must know why is it happened and apply the appropriate solution. We may not able to avoid technical debt but can minimise it as time is money and we can't afford it.
A typescript JS people who breathes React and Node. Long term learning curve is a must to keep us fresh and competitive. Don’t be overwhelmed by the speed.