We don't have siesta, for it's obsolete or not popular in central and north Spain, but (unfortunately IMO), many have the broken divided timetable that could allow a siesta.
That is, many people leave at 2, and comes back to work about 3.30, 4 or even 5!, what makes the day endless, going most of the year back home at night, at 5.30, 6, 7, 8, ...
Timetable does not depend on the IT market but in the general policy in the firm, however, I think I observe (in my friends) that IT people use to have a little more flexible timetables.