Why pre-screen organ-on-a-chip engineers before the interview
Keeping cells alive under flow in a small device is an achievement and it is not the claim that matters. The claim is that the response predicts what happens in a person, and that requires comparison against known compounds with known outcomes. Engineers worth hiring make that distinction unprompted. A short screen asks what their model predicted correctly and where it failed.
What actually matters when screening Organ-on-a-Chip Engineer candidates
- 01
Technique and experimental design
Check hands-on command of soft lithography, PDMS bonding, and perfusion design: SU-8 masters, plasma treatment, shear stress targets, TEER electrodes, and co-culture seeding protocols they wrote themselves.
- 02
Results that went somewhere
Probe which chip models reached a real endpoint: compound screens, DMPK or tox data handed to pharma partners, qualification packages, or published gut, liver, or BBB models.
- 03
Troubleshooting and reproducibility
Test debugging of bubbles, leaks, delamination, cell detachment under flow, and batch-to-batch PDMS variability; ask how they proved reproducibility across chips, operators, and cell lots.
- 04
Documentation and collaboration
Look for SOPs, device drawings, CAD and mask files under version control, ELN discipline, and how they briefed biologists, mask shops, and imaging or assay collaborators.
Pre-screening questions to ask Organ-on-a-Chip Engineer candidates
12 questions grouped by what they test. Ask the same set in every screen and score answers on a consistent scale, or send them as an async video screen and compare answers side by side.
Devices they ran
3 questions01Describe a project where you replicated an organ's function on a chip.
Listen forThe specific function reproduced and how it was measured, with the limits of the model stated.
Whole organ function claimed, or the model described without any functional measurement.
02What experience do you have with microfluidics in these systems?
Listen forDevices they designed and fabricated, with channel dimensions and flow rates described concretely.
Devices bought and used only, or fabrication performed entirely by a facility.
03Can you give examples of using these systems for drug testing or development?
Listen forCompounds tested with the results compared against known clinical or animal study outcomes.
Screening described without benchmark compounds, or predictive claims made without comparison.
Fabrication and cells
4 questions04Can you describe your familiarity with materials used in fabricating these chips?
Listen forMaterial choice weighed against absorption of small molecules, which distorts drug testing results.
Material chosen by convention, or compound absorption into the device not considered.
05What experience do you have with cell culture and tissue engineering in this context?
Listen forCell sourcing, differentiation and culture maintained under flow, with viability tracked over time.
Cell work handed to a collaborator entirely, or viability assessed only at the end point.
06What techniques do you use to integrate sensors into these platforms?
Listen forSensors integrated without disturbing the culture, with calibration and drift handled during long runs.
Sensors added without considering biocompatibility, or drift over a long culture not corrected.
07How do you ensure sterility and biocompatibility during development?
Listen forSterilisation methods matched to the materials, with residues and their effect on cells considered.
Sterilisation assumed harmless to materials, or contamination in long cultures treated as inevitable.
Relevance validated
3 questions08How do you validate the physiological relevance of your models?
Listen forBenchmarking against known responses, with the differences from human physiology stated openly.
Relevance asserted from cell type used, or no comparison against an established reference.
09How do you address fluid dynamics and shear stress in these systems?
Listen forShear calculated and matched to physiological ranges, with its effect on cell behaviour understood.
Flow rates chosen for convenience, or shear stress never calculated for the channel geometry.
10How do you approach troubleshooting and optimising device performance?
Listen forBubbles, leaks and clogging diagnosed systematically, with device variation quantified across batches.
Failed devices discarded without diagnosis, or batch variation never measured.
Reproducible batches
2 questions11What regulatory and ethical considerations apply to this work?
Listen forCell sourcing consent respected, with realistic claims about replacing animal testing rather than overstatement.
Animal replacement claimed outright, or cell provenance and consent not verified.
12How do you collaborate with biologists, chemists and other engineers?
Listen forGenuine two-way work with biologists shaping the device design rather than receiving it.
Devices designed then handed over, or biological requirements discovered after fabrication.
How to score responses
Score every candidate on the same four criteria immediately after the screen. At this stage you are shortlisting for panel interviews, not making the final call.
Technique and experimental design
35%5Names specific chip geometries, flow rates in dyn/cm2, barrier integrity readouts, and explains why each design parameter was chosen.
Results that went somewhere
25%5Points to models adopted by partners or regulators, with cited papers, screening throughput, or data that changed a compound decision.
Troubleshooting and reproducibility
25%5Describes systematic root-cause work, controls run per batch, and quantified variability (CV, replicate counts) rather than anecdotal fixes.
Documentation and collaboration
15%5Produces SOPs others run unaided, keeps traceable design revisions, and translates fluidics constraints into terms cell biologists act on.
Keeping cells alive is not the same as predicting a human response. A one-way video screen asks what was validated.
Try it on HirevireScreening FAQ
Process basics
How long should a pre-screening round for this role take?
Fifteen minutes across eight to ten questions, answered async. Enough to establish devices they built and ran, test their fabrication and culture depth, and check validation practice.
What mix of skills should I expect?
Microfabrication and cell biology together. Someone strong in only one will build a beautiful device that cannot sustain culture, or a good culture in a device that leaks.
Evaluating answers
What is the strongest signal when screening this role?
What the model predicted correctly and where it failed. Engineers doing rigorous work benchmark against known compounds. Anyone claiming physiological relevance without that has not validated anything.
How do I judge their reproducibility?
Ask about variation between devices. Real answers quantify it and describe what they did to reduce it. Anyone who has not measured it cannot tell a real result from device variation.
Go deeper on this role
Sanat has been hiring since 2012 and watching the recruitment industry change up close ever since, and turned that screening process into Hirevire's video screening platform. LinkedIn
