A Czech engineer's CV arrives in English. The employers are listed in English, the project descriptions are in English, the achievements are phrased the way US recruiters like to read them. Everything about that document was translated, and most of what could be verified about it was left behind in the translation.
The CV you receive is a summary of a career you cannot see
The work history behind a Central European senior engineer is largely documented in Czech or Slovak: the company's own site, the local press coverage, the trade registry entry, the internal job title that does not map cleanly onto a US one, the conference talk, the university project. An assessor working only in English sees a clean summary and has no way to press on it. An assessor who reads both sees the source material and can ask about the specific system, the specific outage, the specific team, by name.
The most useful question is one nobody can rehearse
The strongest signal in any senior assessment is what happens when you ask someone to go one level deeper than their CV goes, about their own work. Not a puzzle, not a generic system design prompt, but the actual architecture they say they owned and why they made the calls they made. Rehearsed answers survive generic questions. They do not survive a follow-up question that could only have been written by someone who already read the local source and understood the domain.
Switching languages is itself the test
There is a specific thing worth watching that only appears in a bilingual session. Ask a technical question in the engineer's own language, let them answer at full speed with all their real depth, then ask them to explain the same trade-off in English to an imagined US engineering manager. The gap between those two answers is the most honest measure of what your team will actually receive on a call. Someone can be excellent and lose forty percent of themselves in the second version. That is not a reason to reject them, but you should know it before they join your standup, not after.
What this filters out that a coding test never will
Nobody fails these assessments on syntax. The failures cluster in three places, and all three are invisible on paper: the person who did good work on a team that made the hard decisions without them, the person whose written English is polished because it was assembled slowly and whose spoken English collapses under a follow-up, and the person whose stack looks current on the CV because they listed everything the company used rather than everything they touched. Each of these is a genuinely competent engineer. None of them is the engineer the CV described.
The practical version for a hiring team
You do not need to build this yourself, and you should not have to. But you can ask for it. Ask whoever is sending you engineers whether the person who assessed them speaks the engineer's own language, whether they are technical enough to judge an architecture answer, and whether they read the original-language work history rather than the CV. If the answer to all three is no, you are receiving a translation of a translation, and you are doing the real evaluation yourself on your own time.
Our assessments run in Czech or Slovak and in English, by someone who can judge both the engineering and the communication. See how the assessment works.