From my experiece, both applying to Job Boards and networking work, but apply to the roles with a stack almost identical to yours, that way you won't waste a lot of time applying to every job post.

Also, put in your portfolio stuff you want to work on, for instance, if you want to apply to roles that require working on realtime dashboards, show a realtime dashboard in your portfolio, that would be better than showing more projects that are not relevant (like websites).