Lenovo W540 with i7, 16 GB RAM, 256 GB SSD+1TB HDD and some nividia quadro graphics card.
Software side driven on Ubuntu 16.04.3 HWE enabled with i3 window manager.
When I have to work on Windows (some meanwhile rarely .Net development) i have a Windows 10 VM running on a Proxmox KVM on the company‘s cluster.
When our department is buying some new hardware next year I’m aiming for a powerful 12-13“ book (no MacBook) because the W540 with the large battery is a brick. Maybe the Lenovo X270 or Dell XPS13 full built up.