Is one year enough for a postdoc position to be a fruitful experience regarding my CV?
If you want to join the industry, the shorter you spend on your postdoc the better. If you are familiar with the project, then 8-9 months might be enough to have something out of your post doc experience. Also, one year postdoc is a great chance to focus on the skills that are necessary for you to get into your industry job category.