141 hardware engineer interview questions
Every question in the book has a page here. 12 have a free full answer. The others carry extra explanation that is not in the book — worked numbers and common mistakes — while the full answer stays in the book.
1. Passives & Components
Every design question eventually becomes a part-selection question. Interviewers use components to see whether you know how real parts differ from ideal ones — derating, parasitics, and failure modes.
2. Analog & Op-Amps
Op-amp questions test whether you can derive, not recite. Start every answer from the three rules of negative feedback, then add the non-ideal effects that matter for the case in front of you.
3. Filters, Sampling & Data Converters
Sensor products live and die by the analog-to-digital boundary. Expect questions on aliasing, ADC drive, and why a reading is noisy.
4. Power Conversion
The single most common topic in hardware interviews. Be able to draw a buck converter cold, with waveforms, and to talk through component choice, control loop, layout and protection.
5. Power Integrity & Protection
Power integrity is where power and signal integrity meet: decoupling, plane impedance, ground bounce, and the parts that keep a board alive when the outside world misbehaves.
| PI-01 | How many decoupling caps? | ●● | Free answer |
| PI-02 | Ground bounce | ● | Free answer |
| PI-03 | Why use thick, wide traces? | ● | Going deeper |
| PI-04 | Automotive-grade robustness | ●● | Going deeper |
| PI-05 | Inrush when hot-plugging | ●● | Going deeper |
6. Signal Integrity & Transmission Lines
Every board with a modern processor is a high-speed board. Interviewers want the physics in one sentence, then a number, then what you do about it on the board.
7. High-Speed Interfaces & Memory
Know the PHY of each interface — how it is clocked, coupled, terminated and trained — and always tie the answer back to the board.
8. Low-Speed Interfaces & Embedded Hardware
Questions where hardware meets firmware: buses, GPIOs, resets, and what happens between power-on and main().
9. EMC, ESD & Grounding
Grounding and EMC questions test whether you think in current loops. Every answer starts with "where does the return current flow?"
10. PCB Layout, Stack-up & Manufacturing
Layout questions test whether you can turn electrical intent into copper — and whether the board can be built by the million.
| PCB-01 | Stack-up for a mixed-signal board | ●●● | Free answer |
| PCB-02 | 4 layers with no solid ground | ●●● | Going deeper |
| PCB-03 | Analog/digital partitioning | ●● | Free answer |
| PCB-04 | Top-layer vs inner-layer routing | ● | Going deeper |
| PCB-05 | HDI and via types | ●● | Going deeper |
| PCB-06 | Rigid-flex design | ●● | |
| PCB-07 | Designing for yield | ●● | |
| PCB-08 | Trace current and thermal design | ● |
11. Measurement, Debug & Failure Analysis
Hands-on interviews put a scope in front of you. Debug questions test method: hypothesis, measurement, narrowing down — and knowing when your instrument is lying.
12. System Design (Open-Ended)
Design interviews have no single right answer. The grade comes from your questions, your block diagram, your numbers and the trade-offs you name.
13. Behavioral & Your Own Story
Behavioral interviews decide as many offers as technical ones. Prepare stories in advance; tell them with numbers.
| BH-01 | Tell me about a project | ● | |
| BH-02 | A failure | ●● | |
| BH-03 | Disagreement | ●● | |
| BH-04 | Working with other functions | ●● | |
| BH-05 | Staying current | ● | |
| BH-06 | Why this company? | ● |