Google I/O 2015 happened at the end of May with the usual combination of platform updates, new product announcements, and developer tooling. The headline OS announcement was a preview of Android M, which would later be named Marshmallow. The headline product announcement was Google Photos, an unbundled version of the photo features that had previously been tied to Google Plus.
Android M brought important improvements that mattered to users without being individually transformative. Granular permissions, where applications had to request specific permissions at the moment they were needed rather than at install time. Battery optimisations through Doze mode. USB-C support. Direct Share for content sent to specific contacts. The improvements were the kind that mature operating systems accumulate, useful in aggregate without being individually exciting.
The Google Photos announcement turned out to matter more than the OS update over the years that followed. The product was free, offered effectively unlimited storage at a slightly compressed quality level, and applied automatic organisation through machine learning that was substantially ahead of any other consumer photo product at the time. Search by content rather than by tag. Automatic creation of albums and stories. Face recognition for grouping people across years of photos. Object recognition that let users search for things like beach or dog without ever having tagged them.
The capabilities Google Photos shipped with at launch in 2015 were the result of years of investment in computer vision research being applied to a consumer product at scale. The feature set would have been worth charging significant money for. Google made it free, which both undercut competing services and gave Google access to an enormous additional source of training data for its computer vision systems.
The strategic decision to unbundle photos from Google Plus was tacit acknowledgement that Google Plus had failed to become the social platform Google had hoped for, but that the photo features built within it were genuinely useful and would have a future as a standalone product. The unbundling also signalled a shift in how Google would think about products generally, more willingness to launch focused standalone services than to insist on a unified social platform.
Looking back from a longer distance, the I/O 2015 announcements were a quieter version of the pattern that would repeat through the rest of the decade. The OS updates accumulated incremental improvements. The standalone services applied machine learning capabilities that compounded over time into substantial advantages.