The KISS principle, which stands for “keep it simple, stupid,” is a concept in software development that suggests that developers should strive to keep their code as simple and straightforward as possible. The idea behind this principle is that complex and overly-clever code can be difficult to understand and maintain, and can increase the potential for errors. Instead, developers should aim to write code that is clear, concise, and easy to understand, even if it means sacrificing some optimization or performance. This can help to make the code more maintainable and reliable in the long run.

// Without following the KISS principle, we might write a function like this:
function calculateTotalPrice(price: number, quantity: number, taxRate: number): number {
  const taxAmount = price * quantity * taxRate;
  return price * quantity + taxAmount;
}

// This function is not very simple, and it can be difficult to understand
// what it is doing, especially if you are not familiar with the tax calculation.

// However, if we follow the KISS principle, we can rewrite the function to be
// more simple and straightforward, like this:
function calculateTotalPrice(price: number, quantity: number, taxRate: number): number {
  return price * quantity * (1 + taxRate);
}

// This new version of the function is much simpler, and it is easy to understand
// what it is doing. Even though the original version of the function might be
// slightly more efficient or accurate, the simplicity of the new version makes
// it a better choice according to the KISS principle.`