What skills should part-time developers possess to be effective?

Part-time developers should possess strong technical expertise, adaptability, and excellent time management skills to be effective. Part-time developers need to contribute quickly, without extensive onboarding, which requires deep knowledge of relevant programming languages, frameworks, and tools. Adaptability is also very important, as they often work on very diverse tasks across different projects or technologies.
Strong communication ensures smooth collaboration with the team in the limited hours. Time management and self-discipline: meeting deadlines by putting quality work out, whatever time they have in their schedule. Problem-solving skills and proactive attitude towards work help in efficient handling of problems, so it is their potential contribution to any project.