in full swing

US /ɪn fʊl swɪŋ/
UK /ɪn fʊl swɪŋ/
"in full swing" picture
1.

en plein essor, battre son plein

at the peak of activity or progress; fully active or operational

:
The party was in full swing by the time we arrived.
La fête battait son plein quand nous sommes arrivés.
Construction on the new building is now in full swing.
La construction du nouveau bâtiment bat maintenant son plein.