With the exception of the CAST Permanent (see more information about this selection procedure), once validated, you can no longer modify the content of your application, as EPSO will immediately process the data.
For CAST Permanent, candidates who have submitted an application are encouraged to update it every six months to indicate their on-going interest in that selection procedure and to remain visible to the recruiting services.
You can upload or update your CV within your EPSO Account at any time. However, this information is only used by the recruiting services, and plays no role in evaluation or establishment of your eligibility, etc. in any selection procedure.