If you ignore the touristic Paris words in the beginning, it is a good article for the project overview/news. Sort of Grand Paris 101.

Maybe one thing the article missing is the deployment of  'Worker tracking RTLS system' from a company called Litum to monitor the security of hundreds of construction workers in tunnels (I read here: Grand Paris Express tunnel construction improves employee safety with wearable technology). I believe it is the first time such a safety measure has been deployed at a project of this scale.

https://tunnelingonline.com/tunneling-on-a-grand-scale-in-paris/