Background: "21st century learning" is reliant on not only cognitive competencies such as problem-solving, but also interpersonal (e.g., collaboration) and intrapersonal (e.g., self-regulation) competencies. Building on research in K-12/undergraduate contexts, we investigated cognitive, interpersonal, and intrapersonal learning tactics in a sample of working adults. Method: We conducted 75 interviews with adults in an online Master's in Computer Science (CS) program. We used thematic analysis to organize participants' learning tactics into five key strategies and interpreted strategy/tactic use in the context of a well-known 21st century learning framework. Findings: Interpersonal tactics were perceived as critical across domains, while the relative salience of intrapersonal and cognitive tactics differed depending on the nature of the task. This highlights: (1) critical differences between effective strategies for managing learning itself versus non-learning demands and (2) the value of "making space" for learning alongside other domains of adult life (e.g., work/family). Contributions: We differentiate between tactics employed to master course content (e.g., via educational technology) and those facilitating the development of a supportive learning environment (e.g., via regulation of resources across domains and over time), show utility of the 21st century learning framework for working adults in CS, and discuss issues of identity and learning management.