Wall Preparation for Paint

I've recently started a DIY project on my accent wall. After removing wall tiles and adding some wall panelling, I applied a layer of joint compound over the rough surface. However, despite my best efforts, the wall isn't smooth enough for a paint-ready finish. I'm looking for a professional who can: - Smooth out the wall to a uniform, even finish - Prepare the wall for a matte paint application - Address any imperfections created from the tile removal