I've observed similar technology shifts with backend code (where MySQL was hot in 2003, PostGres in 2006, MongoDB in 2009, Cassandra in 2011, PostGres again in 2015, and now there's this huge explosion of storage solutions) and in platforms (where we were all about the web in 2007, all about mobile in 2010, all about blockchain in 2013, all about smartwatches & VR in 2015, and all about Ethereum & smart contracts in 2018).