This open access book constitutes the proceedings of the 22nd International Conference on Agile Software Development, XP 2021, which was held virtually during June 14-18, 2021.XP is the premier agile software development conference combining research and practice. It is a unique forum where agile researchers, practitioners, thought leaders, coaches, and trainers get together to present and discuss their most recent innovations, research results, experiences, concerns, challenges, and trends.¿ XP conferences provide an informal environment to learn and trigger discussions and welcome both people new to agile and seasoned agile practitioners. This year¿s conference was held with the theme ¿Agile Turns Twenty While the World Goes Online¿.The 11 full and 2 short papers presented in this volume were carefully reviewed and selected from 38 submissions. They were organized in topical sections named: agile practices; process assessment; large-scale agile; and short contributions.

Agile Practices.- From Collaboration to Solitude and Back: Experiences with Remote Pair Programming during COVID-19.- UX Work in Software Start-ups: Challenges from the Current State of Practice.- How to Write Ethical User Stories? Impacts of the ECCOLA Method.- Process Assessment.- Setting the Scope for a New Agile Assessment Model: Results of an Empirical Study.- Towards a Standardized Questionnaire for Measuring Agility at Team Level.- The Impact of Agile Transformations on Organizational Performance: A Survey of Teams, Programs and Portfolios.- Measuring Software Delivery Performance using the Four Key Metrics of DevOps.- Large-scale Agile.- Evolution of the Agile Scaling Frameworks.- Coordination Strategies: Managing Inter-team Coordination Challenges in Large-scale Agile.- Challenges of Adopting SAFe in the Banking Industry - A Study Two Years after its Introduction.- Benefits and Challenges of Adopting SAFe - An Empirical Survey.-Short Contributions.- Using a Low Code Development Environment to Teach the Agile Methodology.- Comparing Participants' Brainwaves during Solo, Pair, and Mob Programming.