While modern silicon tracking detectors offer unprecedented resolution, their full potential can only be harnessed with accurate alignment of all components. Complex silicon detectors as they are operated e.g. at the Large Hadron Collider may require the precise and simultaneous in-situ determination of up to several 100,000s of alignment parameters. This presentation discusses the developments of alignment methodologies to meet these challenges, and corresponding experience obtained with the CMS all-silicon tracker.