Here in the EU, if there are terms in an employment contract that effectively mean a non-compete for X length of time after leaving that employment, they are completely unenforceable once the employment contract is terminated. The key terms are "contract" and "terminated". The contract no longer exists legally once the employment is terminated.
If a company wants non-compete methods, then they have to request that the newly-ex-employee sign a new contract to not compete with the previous employer's competitors, and in every case that I have heard of, the monetary terms for that non-compete had to be very very generous in order for the newly available employee to not work for the next 6 to 18 months in the business. Some in this situation went on training courses to stay current, others branched out into differing areas of work, all while getting handsomely paid not to work for the competitor.
Amazon have their head up their ass regarding the treatment of their employees for a long time in the US, and it'll come back to bite them. At least in the EU the employee protection legislation prevent such entities from taking that level of advantage of their employees. I'll be glad if/when karma comes back to burn Bezos and gang over their unethical actions and general mistreatment of their staff.