Speiros

Guide · Guide · US hiring teams, founders, and search firms

How to Source Passive Candidates for a Hard-to-Fill Role

A practical guide to widening the search without losing the role’s essentials, finding adjacent talent pools, and turning an evidence-backed shortlist into relevant outreach.

Search planWiden the pool without weakening the role
Research frameSearch plan
011. Protect022. Flex033. Explore044. Reach out

A visual frame for sourced research; it does not represent survey results.

01

First, identify what is actually making the role hard to fill

A thin search result does not automatically mean the required talent does not exist. The location may be too restrictive, the job title too specific, or the brief may combine responsibilities usually held by different people. Before purchasing candidate sourcing or restarting a search, ask the hiring manager what the hire must accomplish in their first six to twelve months.

Turn each requirement into observable evidence. “Knows our industry” is difficult to search for or assess; “has deployed a solution in an environment with comparable safety constraints” suggests both a search path and a question to ask. It also helps the team decide when someone with an unconventional résumé is worth contacting.

  • Essential: a skill or constraint without which the person cannot perform the role.
  • Transferable: experience gained under a different title or in another industry that applies to the work.
  • Preferred: a reassuring signal, such as a recognizable former employer, that is not itself proof of fit.

02

Relax one requirement at a time and inspect the results

Changing every filter at once can create a large, unhelpful list. Instead, test separate hypotheses: the same skills in a neighboring industry; the same problem solved under a different title; a wider location range if the on-site requirements permit it. Compare the people you find against the evidence the role needs, not just the size of the list.

Entirely hypothetical example: a company near Chicago needs someone to lead industrial automation deployments for customers. Requiring one exact title, a narrow manufacturing segment, and experience at a direct competitor could exclude commissioning or systems-integration leaders who have handled similar work on customer sites. The team might expand to those backgrounds while retaining any safety and travel requirements that truly matter.

  • Record which requirement you changed and why.
  • Review a few representative profiles with the hiring manager before widening the search again.
  • Treat skills that are not visible on a public profile as questions to check, not facts to assume.

03

Build talent pools around the work, not only the title

Passive candidates do not necessarily signal that they are open to a move. Start with problems they may have solved: multisite rollouts, market launches, regulated product development, or leadership of a specialized team. Search adjacent titles, then the functions and companies where that work happens.

In the hypothetical Chicago example, potential pools include systems integrators, equipment suppliers, technical teams at industrial customers, and deployment program leaders. Each has a tradeoff: someone from the same segment may need less domain ramp-up, while someone from a neighboring environment may bring a different approach. Establish relevance for each person rather than assuming an entire pool is a fit.

  • List nearby titles and responsibilities, including terms candidates may use instead of the company’s job title.
  • Give each pool a testable rationale, such as “these teams already manage customer-site commissioning.”
  • For each shortlisted person, note one relevant public detail and one question to clarify; do not infer interest or availability.

04

Turn the shortlist into a credible first message

A shortlist is only useful if you can explain why each person is being contacted. Before outreach, make sure the role, its material constraints, and the reason for the approach are easy to state. If compensation, on-site expectations, or decision-making scope will determine interest, settle those questions with the hiring team first.

Fictional message, to use only after checking its details: “Hi Jordan, I came across your work in industrial commissioning and thought it was relevant to a role leading customer deployments near Chicago. The position owns technical coordination across those rollouts. Would the scope be worth a brief conversation? I can share the expected on-site and travel requirements.” This offers a reason to talk without claiming to know Jordan’s intentions.

  • Lead with a relevant detail rather than generic praise.
  • Explain the problem to solve and one important condition of the role.
  • Make it easy to decline; keep any follow-up measured and stop if the person says no.

05

When buying sourcing, evaluate evidence and scope—not just list size

Ask a sourcing provider how it translates role requirements into searches, explains why profiles belong on a shortlist, and flags missing information. Specify what you are buying: identification, human review of a shortlist, outreach drafting, message delivery, or response follow-up. A list of names and a set of candidate conversations are different deliverables.

In a trial or initial engagement, review a sample of accepted and rejected profiles with the hiring team. If rejections consistently point to one missing qualification, sharpen that requirement. If the profiles look relevant but conversations do not start, examine the opportunity and the outreach instead. Track shortlist relevance, contacts made, and qualified conversations separately rather than judging the search by profile count alone.

Speiros describes a sourcing agent that searches through a connected LinkedIn account and builds a shortlist with reasons attached, alongside an outreach agent for starting personalized conversations. The hiring team sets the level of supervision and makes hiring decisions. If considering it for a difficult search, assess those steps against your brief, account access, and desired scope; available features depend on the connected LinkedIn product, subscription, and permissions.

  • Request an example of the reasoning behind both an included and an excluded profile.
  • Clarify who approves search criteria, messages, and follow-ups.
  • Check the product and pricing pages for scope and commercial terms before purchasing.

Sources and further reading

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How to Source Passive Candidates for a Hard-to-Fill Role | Speiros