In order to deliver customised content and improve user experiences, over-the-top (OTT) providers must adopt efficient customization and recommendation algorithms as the OTT sector continues to grow. The objective of this chapter is to investigate the developments, difficulties, and best practises relating to personalization and recommendation algorithms in the over-the-top environment. The significance of customization and recommendation algorithms in the over-the-top OTT business will be covered in the proposed chapter. The proposed chapter seeks to provide readers interested in customisation and recommendation algorithms within the OTT business with useful information and helpful advice. It will discuss how the OTT market is changing and provide practical advice to OTT service providers looking to improve their users' user experiences via sophisticated personalisation and recommendation algorithms.