I am not asking the CEO to be familiar with the details of programming or with whatever other technical minutiae a company is forced to deal; they can – however – demand insurance that their systems are properly tested, even if they don't understand the details of those procedures.

CEOs are the public faces of companies; with which comes higher pay but more responsibility. Conversely, employees shouldn't be sacked for honest mistakes, since they are supposed to be faceless. If an employee makes a mistake at a company, and that company does not have procedures in place to protect against that mistake; then it's the company's problem, not the employee's. And when it's the company's problem, it becomes the CEO's.

The CEO should set the organisational culture. I would argue that - alongside the fact this isn't the first issue of this kind by the sounds of things - the fact that a serious error like this could be caused by a developer making a typo reflects very badly on the culture of the organisation.

Resignation definitely does not seem like the right direction, and is likely a panic reaction.

That said. The ceo is responsible regardless of their knowledge - in tech heavy companies, like this apparently is, they'd usually appoint a trusted cto for things like this.

But failure always run up the chain of command, and ofcause it should. It is after all why CEOs are paid well. They are responsible.

Quality Assurance is the responsibility of management. In PRINCE2 e.g. it is stipulated to be organized by the steering group.

It other words: Management (steering group or CxO level) should ensure there is a QA organization to handle this. I don't know if this was the case here or if somebody just 'tested in production'.

"Figure out who won what" is kind of the core business function of a lottery, obviously upper management is responsible for ensuring that happens correctly. Not necessarily through direct involvement, but through ensuring the right people and processes are in place.

If they aren't responsible for that, what else would a lottery CEO be responsible for?

The winnings were calculated and paid out correctly. The error was just in the string formatting in some App notification.

The entire justification that has always been given for CEOs deserving astronomical salaries is "because they take responsibility when things go wrong", hence the term "golden parachute". We should be more upset that this isn't the norm anymore, because it's proof that CEOs don't deserve their salaries.