Trending @Capgemini; Switching Domain

I have been working as an application support analyst in CG for the last 3 years. And now I wanna switch my domain to Backend like Java spring boot and micro services. I have been trained in JFS but as I have not worked in that domain I forgot now I started to learn things again. Is it helpful to learn backend and get a chance in backend projects in CG itself? And also how much time will it take to learn Java backend? Guide me please