#Ruby on Rails 今週の必読記事4件（TechFeed Weekly 2021-02-21）

海外版: 1. Rails 6.1: 孤立化したレコードのリストを取れる'missing'クエリメソッドが追加（翻訳） 2. Rails 6.1.3 has been released 3. Certific, a health tech startup from the founder of TransferWise, aims to be the rails for certified home testing – TechCrunch 4. WandaVision episode 7 recap: Marvel show goes off the rails in the best way