Almost anything written by the inimitable LWN.net[1] — their feature-length articles, technical conference coverage, etc. Something that springs immediately to mind is their 7-part series[2] Linux kernel namespaces from 2013. The full series is linked to at the bottom of part 1:
You can see their entire kernel archives here[3]. And as to their excellent conference coverage, you can browse conferences by year[4]. Most recently, here's[5] their roundup of "Linux Storage, Filesystem, Memory-Management and BPF summit".