A set adverbial phrase meaning 'as usual' or 'as always', often used to describe habitual actions or predictable situations.
He was late as usual.
As always, she was sitting alone in the café.
A fixed phrase combining いつも (always) + の (possessive particle) + ごとく (classical adverbial form of 如し, meaning 'like' or 'as'). The ごとく part is a classical Japanese form that survives in set expressions.