A321 First Officer reported a loud bang and felt a jolt to the aircraft followed by an ENG 2 STALL ECAM. Flight crew returned engine to normal operation but later it experienced a second series of stalls. Flight crew continued to destination with engine at idle power.

Narrative

Prior to push back; the Captain and I 'chair flew' the new Date SOPs to include actions/call outs for Engine Loss at V1 and CAT 1 ILS and Engine Out Approach/Landing and Go Arounds. This timely review significantly reduced our workload in flight and reduced the number of errors committed during the ensuing situation given the otherwise lack of training on the new SOPs.Climbing through 17;000 ft. we heard a loud bang and felt a jolt to the aircraft followed by an ENG 2 STALL ECAM. The stall cleared itself in less than 5 seconds. Captain/Pilot Monitoring referenced the QRH procedure. The Flight Attendants and a Pilot riding in the cabin informed us that a Visual Flame was observed in the #2 Engine associated with the Compressor Stall; but no external damage was observable. Engine was returned to normal operation following completion of the QRH procedure. At 35;000 ft.; approaching Top of Descent; the #2 engine experienced a second series of Stalls. The Stalls included an ECAM ENG 2 STALL Message; Erratic EPR Indications; Audible Banging and Visual Flames as reported visually; again from the cabin. The First Officer/Pilot Flying immediately retarded the Thrust Lever and the Stall cleared. Captain/Pilot Monitoring called ATC for a decent and executed QRH procedure. We elected to operate the #2 Engine at idle power for the duration of the flight. We requested priority handling with Center and requested a descent and expedited approach to ZZZ. 'Non-routine landing considerations' were reviewed and a precautionary landing was conducted to XXC. Fire/safety personnel inspected the aircraft after landing and indicated no visible damage. Priority handling was terminated and we taxied to the gate.Landing with one engine at IDLE thrust after running the QRH procedure is somewhat confusing. While not technically a single engine approach; we treated it as such (since it could turn into one at any second). It would be helpful if the Engine Stall checklist directed a reference to 'Approach Considerations' on the QRH. This section is difficult to find in the heat of battle.