on the up (and up) idiom
mainly US informal诚实的;值得信赖的
Someone who is on the up (and up) is honest and can be trusted.
UK蒸蒸日上；节节高
improving all the time
Her career has been on the up and up since she moved into sales. 自从转做销售后，她的事业蒸蒸日上。