Rune worked on the ruby/ruby repository, focusing on backend development with Ruby to address compatibility issues in IRB. During the month, Rune removed the y Object extension from IRB, a change aimed at preventing conflicts with widely used gems such as factory_bot and prawn. This adjustment decoupled the extension from default IRB usage, reducing the risk of breakages when requiring extensions. Rune implemented an optional manual require pathway, allowing users to load 'psych/y' only if needed. The work demonstrated a careful approach to ecosystem compatibility, prioritizing stability and flexibility for developers relying on Ruby’s backend infrastructure and extension mechanisms.