This chapter delves into the architecture and design principles behind Nextflow, emphasizing its modular approach in pipeline development and data flow paradigm. It discusses containerization of tasks, orchestration of tasks to executors like AWS Batch, and the intricate details of scientific computing pipelines, focusing on the RNA seek pipeline example. The chapter also explores scaling and parallelism in scientific computing pipelines, decision-making processes at Secara, and the evolution of the Nextflow community through community-contributed content and industry collaborations.