The phrase "immense success" means achieving a very big and great accomplishment or victory in something. It suggests that someone or something has done extremely well and has been very successful. Full definition
I then started to model my focus after someone who was already seeing immense success and I too started to see that level of success. (lancewills.com)
Though the company has experienced immense success over the past four decades, the brand has remained firmly rooted in their humble beginnings and focused on promoting sustainable fashion and global change through trade. (musingsonmomentum.com)