This summer's exams may be back to normal on the face of it, but Covid anxiety is still having an impact on A-level and GCSE pupils.
Exams are going ahead for the second year running after being cancelled in 2020 and 2021.
The qualifications watchdog said there are still some measures in place this year to reflect disruption to learning.
Wales' biggest school will see 6,500 papers sat over the month, with more than 1,000 pupils at the same time.
At the 2,400-pupil Whitchurch High School in Cardiff, making sure it all runs smoothly is "really quite tricky," assistant head teacher Jonathan Davies said.
Mr Davies said exams were "pretty much back to normal" after the first full school year without Covid measures in place, but that "the remnants of Covid-19 are still carrying on unfortunately with some of the students - they're very anxious".
