The Thinkpad line was acquired by Lenovo from IBM in 2005. They've done a good job in maintaining the quality of the product line but some products with the 'Thinkpad' branding is absolute crap. Technology products are hard to rank for build quality in my opinion. When Lenovo again made an acquisition of Motorola Mobility in 2014, I thought they'd do a good job of maintaining Motorola phones just like Thinkpad. At first, you had almost a close to Vanilla version of Android with regular updates but since 2019+ they stopped maintaining Android Security updates and releasing whole Android versions on some of their bottom-tier phones. Things change quickly in the technology department so BIFL ranks are difficult.