We’ve made some adjustments that will technically remove all ‘Guru meditation’ errors, but may still cause some form of timeout when we get a big rush of traffic particularly to the wiki. However, we’re hoping the performance adjustments prevent those stampedes either way.
One other issue causing 503s was discovered to be intermittent hardware issues which are also being addressed, but obviously can’t be fixed with software optimisations. So, fighting a multi-headed snake right now 
Closely monitoring since today’s changes.