Resources · Hiring & architecture
This is a structural limit rather than a criticism. The question is what an agency does about it, because the cost of not answering lands on the end-client relationship rather than on the placement.
Specialist voice and network roles fail differently from other technical placements. A mis-hired developer is usually visible within weeks. A mis-hired voice engineer is visible when a cutover goes wrong at 2am on a Saturday, in front of the client, four months into an engagement the agency has already been paid for.
By then the damage is not the placement. It is the account.
A skilled technical recruiter can establish a great deal without engineering knowledge: employment history, tenure patterns, certification validity, notice period, compensation expectation, communication ability, whether the candidate has worked at the scale the client operates at, and whether their stated reason for leaving holds together.
That is real screening and it filters a lot.
What it cannot establish is whether the candidate can do the work. Not because recruiters lack diligence, but because the signal that distinguishes a competent voice engineer from a confident one is only legible to someone who has done the job.
Certifications do not close the gap. A current CCNP Collaboration proves someone passed an exam, which is meaningful and is not the same as proving they have run a migration, diagnosed a one-way audio fault under pressure, or made a dial-plan decision they had to live with afterwards.
Resumes close it even less. The specific failure is that the vocabulary is public. Every term a real engineer would use is in the job description the candidate is applying to, which means keyword density measures how carefully someone read your posting.
The discriminators are unglamorous and they are consistent across platforms. A practicing engineer can hear the difference inside a few minutes; a keyword match cannot see it at all.
Call routing is the tell. Partitions and calling search spaces are conceptually simple and are where people who have only supported a system, rather than designed one, run out of road. Ask someone to explain how a device decides which pattern it can reach, and the answer separates configuration-following from understanding.
Dial plan reasoning is the second. Route patterns, translation patterns, and the order in which they evaluate — someone who has built one explains it as a sequence of decisions; someone who has not describes the screens they clicked.
Class of restriction and automatic route selection occupy the equivalent position. The platform's logic is different enough from Cisco's that people who claim both frequently have depth in one and exposure to the other — which is fine, and is exactly the thing worth knowing before submitting them.
Direct Routing is where most current demand sits and where the shallowest claims cluster, because “we moved to Teams” describes a very wide range of actual involvement. Session border controller configuration, voice routing policies, and media bypass are the areas where genuine hands-on work shows. Someone who ran a real Direct Routing deployment has an opinion about media bypass. Someone who attended one has heard of it.
Failure handling is the most reliable signal of the set, and it is platform-independent. Ask how they would approach one-way audio. The shape of the answer — whether they reason about media path and NAT traversal, or list things to restart — tells you more than any credential.
None of this requires the person asking to be a specialist in every platform. It requires them to have been an engineer. That is the whole gap, and the questions that actually separate candidates covers the question set in more depth for anyone conducting the interview directly.
For an internal hiring manager, a bad specialist hire costs ramp time and a re-run of the search. For an agency the arithmetic is different and worse:
The last one is the structural point. An agency's exposure does not close when the invoice is paid, but its involvement does.
Hire an engineer into the recruiting function. It works and it is expensive — you are competing for the same scarce person you are trying to place, to have them conduct interviews rather than engineering. It only pencils out at real volume in one platform family.
Lean on the client's engineers. Common, and it quietly transfers your value proposition to the client. If their team is doing the technical screening, they are performing the service they are paying you for.
Sub-contract the technical layer. The screening is performed by a practicing engineer, the agency keeps the client relationship, and the submission carries validation the recruiter could not have produced alone.
The third is the model Lumensoft operates for staffing agencies: you submit the role, a practicing Solution Architect conducts the technical interview, and you present a candidate who has been assessed on hands-on depth, protocol fundamentals, failure-handling judgment and communication rather than on keyword overlap. That is what Solution Architect Validated™ means, and it is our own standard rather than a third-party certification.
The commercial shape then follows the same question every placement does — whether the engineer is employed by you or by the client — which splits into Co-Managed engineers, where Lumensoft employs and the client directs the work, and Dedicated engineers, where the client hires directly. Co-Managed roles carry a 7-day shortlist guarantee; Dedicated hires carry a 30-day hiring guarantee and a 90-day replacement guarantee.
Four questions, answerable from your own data, usually settle it faster than a debate about capability.
What is your fill rate on Cisco, Avaya and Teams roles compared with your overall fill rate? A material gap localizes the problem to screening rather than sourcing.
How many specialist submissions were rejected by the client's technical team rather than by the hiring manager? Technical rejection is the specific signal. Rejections at the hiring-manager stage are a different problem.
On your last failed specialist placement, at what point did the mismatch surface — week one, or month three? Month three means nobody in the chain could assess depth, including the client.
Who conducted the last technical interview for a voice role you placed, and had that person configured the platform in question? If the honest answer is the client's engineer, the client is doing the work they hired you for.
The second question is the one to run first. It is in your ATS already, and it is the difference between a sourcing problem and a screening problem — two situations that look identical from a weekly numbers meeting.
A sub-contractor arrangement is scoped per role rather than as a retainer, so it is reasonable to test it on one requirement you would otherwise struggle to fill.
Related
The questions that actually separate candidates on Cisco, Avaya and Teams roles — usable whether or not you work with us.
Hiring & architectureA decision framework based on duration, employment risk and how much direction you want to give.
Who we serveThe sub-contractor model: you keep the client relationship, a practicing Solution Architect performs the technical screening.
Thirty minutes to scope a sub-contractor arrangement on a role you would otherwise struggle to fill.