Get Candidate Pipelines

Returns every job role this candidate is in the pipeline for, with the candidate's per-role context (stage, fit score, interview count, latest interview). Powers the "Roles in pipeline" card on the candidate detail page.

Source-of-truth is the job_role_candidates junction table — that's the only signal that means "this candidate was intentionally attached to this role" (a candidate could appear in interviews on a role they were never sourced for, e.g., if a recruiter hand-created an interview row bypassing the candidates tab; we ignore that edge case here).