In this video, Brian Castle reflects on the evolution of his workflow from 2023 to 2026, highlighting how multitasking with AI agents has become central to his daily work as a builder. Initially, AI tools served as enhancements to manual coding and writing, but by 2025, AI became a true collaborator, handling most creative tasks through spec-driven development. In 2026, Brian has embraced orchestrating multiple agents simultaneously, focusing primarily on shaping and refining specifications while agents execute the work. This shift has made multitasking with agents a natural progression rather than a mere productivity hack.
Brian discusses his exploration of various modern agentic development tools designed to support multitasking, such as Cursor, Claude Code, Conductor, and Super Set. While each tool offers similar layouts with sidebars for repositories and workspaces, Brian favors Super Set for its native Claude Code integration, intuitive handling of multiple work trees, and better alignment with his workflow. He appreciates how Super Set allows him to seamlessly switch between different projects and branches, facilitating parallel development and review processes.
A significant part of Brian’s workflow involves blending product development with marketing efforts. He builds internal tools like Spark Drop and Brain Down to manage content ideas and markdown files, respectively, and creates reusable agent skills to automate tasks such as generating marketing pages and starter kits. This integration enables him to work on product features and marketing assets side by side, often within the same codebase but across different work trees, enhancing efficiency and coherence between development and promotion.
Brian also emphasizes the power of mobile multitasking with agents, using Cloud Code on his phone to keep agents working on tasks outside of traditional office hours. This approach optimizes downtime by allowing agents to analyze codebases, conduct research, and develop content while he focuses on other activities. He highlights his custom agent setup on a dedicated Mac Mini, where multiple agents handle recurring tasks like daily synthesis reports and content development pipelines, demonstrating a mature, automated workflow that runs continuously.
Finally, Brian showcases how he leverages Claude Co-work agents in conjunction with his custom-built tools to manage content creation collaboratively. His agents generate ideas, draft content, and integrate feedback through an API-connected interface, enabling a smooth human-agent partnership. This system exemplifies the future of builder workflows, where human creativity and AI efficiency blend seamlessly, making multitasking with agents an essential and natural part of modern development practices.
