Does scoring above the ATAR cut-off for a university practically guarantee entry? I'm just asking since UNSW comp eng needs an ATAR of 91.35 and I got 94.95+2 but am still paranoid.
The cut-offs you see on UAC's website are the cut-offs for the students which commenced uni this year.
These cut-offs are virtually always subject to change year-on-year.
Keep in mind that the cut-off represents the ATAR of the last successful applicant (i.e. the one with the lowest ATAR) although this does not count the addition of bonus points or other decisions made at the uni's own discretion.
Cutoffs are based on demand & supply. While most courses don't change that much (usually within +/- 0.5), some have been known to fluctuate quite a bit (e.g. Pharmacy was 85 for 2012 entry but 90 for 2013 entry)