This last year has seen the release of Ruby 3.1 and Rails 7.0 with its exclusive use of Zeitwerk and shift away from Node and Webpacker to Hotwire. React, Webpacker, Yarn and Jest are still used widely with Rails but Stimulus adoption has been significant.
At my employer European PSD2 has continued to require significant attention with a rewrite of Redsys payment integration using REST and the addition of Cardinal Cruise. We have also refined shipping method selection and handling of stock-outs.
New gems used this year included Gala for ApplePay. Open source contributions included replacing the Resque web-runner by merging the abandoned Vegas gem.