Direct answer
A source pack is the artifact senior sourcers should build before they start running searches. It turns a vague req into must-have signals, adjacent titles, donor companies, source lanes, false-positive filters, outreach angles, and stop rules.
Why single-string sourcing breaks
One giant Boolean string hides the reason a search is failing. Source packs separate the market into lanes so you can test direct-fit profiles, adjacent titles, donor companies, public technical evidence, academic evidence, and rediscovery one lane at a time.
Operating notes
- Define the strict market first.
- Build 3 to 5 lanes instead of one giant search.
- Attach false-positive filters to every lane.
- Track what worked so it becomes project memory.
What belongs in the pack
A good pack includes the role summary, strict evidence, flexible evidence, target titles, adjacent titles, companies, public surfaces, clearance or license caveats, and hiring manager calibration questions.
How to use it with a hiring manager
Bring the source pack to calibration. Show the strict market, the expanded market, where the pool collapsed, and which tradeoff would increase yield first.
SourcingOS workflow
Use the JD Strategy Tool to build lanes, BooleanOS to generate strings, and Candidate Search to keep public evidence and recruiter confirmation separate.
Copy-paste starting strings
("DevSecOps Engineer" OR "Platform Engineer") AND (Kubernetes OR Terraform OR Docker) AND (FedRAMP OR RMF OR ATO)("Machine Learning Engineer" OR "MLOps Engineer") AND (RAG OR embeddings OR "vector database") AND (Python OR PyTorch)("Registered Nurse" OR RN) AND (ICU OR ER OR NICU) AND (BLS OR ACLS)FAQ
Is a source pack just a Boolean string?
No. The Boolean string is one output. The source pack is the search plan around it.
Should every recruiter build one?
For high-volume evergreen roles, maybe not. For hard-to-fill technical, cleared, healthcare, or AI roles, yes.