For compound tenses, you must invert the subject and the auxiliary (être or avoir).
Comment a-t-il travaillé ?
(the "t" in "a-t-il" is here only for euphonic purposes)
In many cases, basically every time the subject is not a pronoun, the subject is duplicated using a pronoun.
Comment la réunion s'est-elle passée ?
In oral or colloquial language, the subject-verb inversion tends to disappear, but for compound tenses it remains, except that the whole verb comes before the subject.
Comment s'est passée la réunion ?
Except when the subject is a pronoun, then the inversion is most often left aside.
Comment ça s'est passé ?
Comment il a travaillé ?
These non-inverted phrases are not correct, strictly speaking, and should not be written. However, that's the way most natives would say things orally, so you will see it written as well.
So for your specific examples, the correct phrases would be :
Comment as-tu travaillé comme ça ?
Comment est allé le weekend pour toi ? (colloquial)
Comment le weekend est-il allé pour toi ?
On a sidenote : grammar aside, "how did [...] go ?" would not translate to "comment est allé [...] ?", but rather to "comment s'est passé [...] ?". Your sentence is understandable, but unusual.