Managing at a company with no levels – how to handle career progression

I am a new manager overseeing a team of 10 software developers of varying skill and experience. The hr and leadership team states that they want to keep the org ‘flat’ and thus do not assign levels such as sd1, sd2, junior, senior, etc.

Instead people are given ‘titles’ indicating their focus.

While i can incentivize and encourage my team with opportunities to work on projects across the company which will grow their skills and experience, and i can recommend folks for bonuses – I am having a hard time calibrating my expectations without having assigned levels.

Any suggestions how to think about this?

Currently I set very high expectations for everyone and coach exeryone toward the goal of excellence but Im used to having levels as a tool for rewarding and incentivizing.