Sourcing vs. passive recruiting
Posting an opening and waiting for applications is passive recruiting. Sourcing is actively going to find people who are probably not even looking at job boards: on LinkedIn, GitHub, industry communities, or referrals from your network.
Main channels
LinkedIn Recruiter and boolean search are the most common starting point. For technical roles, GitHub and specialised communities give a better signal of real skill than a resume. Referrals still convert best, even at lower volume.
When to invest in sourcing
If an opening has gone 2-3 weeks without qualified candidates from direct applications, that is the sign you need active sourcing, not more time on the same posting.
Frequently Asked Questions
They are close. Headhunting usually means direct contact with very specific profiles, sometimes employed at another company.
It depends on volume. On small teams the same recruiter does both; on large teams the roles split.
Between 15% and 30% is reasonable, depending on how personalised the message is and how specific the profile.