Every vendor sounds equally confident on the phone. The difference shows up in what they can produce when you ask a specific question, so here are six of them. They cost you two minutes, they are equally fair applied to us, and they tell you quickly whether anyone actually looked at the person whose CV you are holding.
What exactly did you assess, and for how long
The useful answer names a format and a duration. A recorded technical conversation of a stated length, against a stated role. The answer that should worry you is a description of a process in the abstract, or the word vetted repeated with more emphasis. If nobody can tell you how long they spent with the person, nobody spent long with the person.
What could you not conclude
This is the single most revealing question, because a real assessment always has edges. Ask which areas remain unproven and where the evidence ran out. A vendor who says everything checked out has either not assessed anyone or is not going to tell you what they found. Any conclusion that cannot come back negative is a sales line rather than a finding.
Show me the words the engineer actually used
Adjectives are free. Ask for specifics from the assessment itself: how the engineer described a decision they got wrong, how they explained a trade off, what they said when pushed past the edge of their knowledge. Summaries hide everything. Quotes and specifics are hard to manufacture and easy to check against your own interview later.
How was technical English judged
Not a certificate level, which tells you nothing about a design discussion at speed. The answer should be about working communication: can this person disagree with an architect in a meeting, ask a clarifying question before building the wrong thing, and write an incident summary your team can act on. That is the skill that decides whether a remote hire works.
Who pays you, and when
The incentive is more predictive than the pitch. Find out whether the fee is one time or recurring, whether it grows with the length of the engagement, and whether the vendor sits in the payment path between you and the engineer. A recurring margin creates a permanent interest in the arrangement continuing regardless of how it is going. A one time fee at introduction does not.
What happens if this does not work
Ask for the replacement terms, the window, and what triggers them. Then ask what happened the last time it was used. A vendor who has never had a placement fail has either placed very few people or is not telling you about the ones that did. The answer to this question is where you find out whether you are buying a relationship or a transaction.
Ask us all six. Every engineer we introduce comes with the written record to answer them. Talk to us.