Why pre-screen 5G engineers before the technical panel
Planning tools produce coverage maps that are confident and often wrong once a real building, a tree line or a neighbouring cell is involved. The engineers who are useful have walked a site after deployment, compared measurement against the model and adjusted. A short screen asks what the coverage model got wrong, which separates deployment experience from standards knowledge immediately.
What actually matters when screening 5G Systems Engineer candidates
- 01
Technical depth
Check command of 3GPP Release 15 to 17 specifics: NR PHY numerology, MAC scheduler behaviour, massive MIMO beam management, SA versus NSA anchoring, and N2/N3 interface signalling.
- 02
Work that shipped
Ask which gNB deployments, field trials, or O-RAN integrations they took to live traffic, including cell counts, bands, vendors, and throughput or handover KPIs achieved.
- 03
Diagnosis under uncertainty
Probe how they isolated intermittent faults: RRC drop spikes, UPF packet loss, or IOT failures, and which traces (Wireshark, Keysight, TEMS, gNB logs) proved root cause.
- 04
Working across the org
Assess how they coordinate with core network, RF planning, chipset vendors, and operator acceptance teams when spec interpretations or acceptance criteria conflict.
Pre-screening questions to ask 5G Systems 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.
Networks deployed
3 questions01Can you tell me about your experience with network deployment?
Listen forDeployments they worked on with site counts and their own scope, distinguishing lab work from live network.
Experience limited to laboratory integration, or no network that carried live traffic.
02What role did you play in the design or development of a network?
Listen forSpecific design responsibility, with decisions they made and the constraints they were working against.
Involvement described at programme level, or no design decision they personally owned.
03Can you discuss a time when you improved network efficiency?
Listen forA measured improvement in throughput, capacity or energy, with the change and the measurement described.
Improvements claimed with no measurement, or changes attributed without isolating their effect.
Radio and core
4 questions04How familiar are you with the different network deployment modes?
Listen forThe core dependency and migration path understood, with practical experience of at least one mode.
The modes treated as interchangeable, or migration implications not understood at all.
05What is your knowledge of multiple antenna technology in these networks?
Listen forAntenna configuration understood in practice, with the gap between theoretical and achieved gains acknowledged.
Theoretical capacity gains quoted, or no experience of what is achieved in a real deployment.
06Can you discuss why beamforming matters in this technology?
Listen forExplained through coverage and interference outcomes, with the tracking and mobility challenges acknowledged.
Explained only as a concept, or the difficulty of maintaining beams to moving devices ignored.
07How familiar are you with the architectural principles of these systems?
Listen forNetwork functions and their interfaces understood, with slicing described in terms of what it requires.
Architecture recited from diagrams, or network slicing described without its operational requirements.
Live troubleshooting
2 questions08How proficient are you at troubleshooting network issues?
Listen forA structured approach across radio, transport and core, with measurement used to isolate the layer at fault.
Problems escalated to vendors immediately, or no method for isolating where a fault sits.
09What challenges did you face during a deployment, and how did you handle them?
Listen forReal obstacles such as backhaul capacity, site acquisition or interference, with how each was resolved.
Challenges described as schedule or budget, with no technical problem from the deployment itself.
Security and testing
3 questions10What are the security risks in these networks and how would you mitigate them?
Listen forRisks across the radio, transport and virtualised core, with supply chain and slicing isolation considered.
Security described as encryption alone, or virtualisation risks not considered at all.
11What experience do you have testing these networks and systems?
Listen forDrive testing and measurement against acceptance criteria, with results compared against the planning model.
Testing limited to vendor acceptance, or field measurement never compared against predictions.
12How do you ensure the performance and quality of a deployed system?
Listen forPerformance monitored continuously using user experience measures, rather than only network-side equipment counters.
Quality assessed from equipment counters alone, or no measure of what users actually experience.
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.
Technical depth
35%5Cites clause-level 3GPP detail, explains scheduler and beamforming trade-offs, and distinguishes SA rollout constraints from NSA anchor dependencies fluently.
Work that shipped
30%5Names live networks or trials with band, vendor, and cell scale, plus measured gains in throughput, SINR, or handover success rate.
Diagnosis under uncertainty
20%5Walks through a messy call-failure investigation, showing how log correlation and layered elimination separated UE, RAN, and core faults.
Working across the org
15%5Describes driving cross-vendor IOT sessions or acceptance sign-off, resolving spec disputes with evidence rather than escalation, and documenting agreed outcomes.
Coverage models are confident and often wrong once a building is involved. A one-way video screen asks what theirs got wrong.
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 deployments they worked on, test their architecture knowledge, and hear a real troubleshooting story.
How much does operator experience matter?
Considerably. Vendor and operator roles differ, and someone who has only integrated equipment in a lab will need support with the operational constraints of a live network.
Evaluating answers
What is the strongest signal when screening this role?
A gap between the model and measured performance. Engineers with deployment experience have that story. Anyone whose networks performed as planned has worked from documentation.
How do I judge their architecture knowledge?
Ask about the difference between deployment modes and what each requires. Real answers cover core dependencies and migration. Anyone treating them as interchangeable has not deployed either.
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
