Hardware Engineer Interview Questions UK: 8 Real Questions and What Interviewers Want

Before your Hardware Engineer interview, it helps to see the questions from the interviewer's side. We have picked eight from our set of 16 and added the reason each one gets asked.

Eight Hardware Engineer interview questions, and what the interviewer is thinking

1. Walk me through how you design a power supply for a new board, from requirements to component selection.

Why they ask: Power design is central to hardware engineering and reveals depth of thinking.

2. What are your main considerations for PCB layout, and how do they affect signal integrity and EMC?

Why they ask: Layout quality determines whether a design works and passes compliance.

3. How do you select components for a new design, and how do you handle obsolescence and supply risk?

Why they ask: Supply chain resilience has become a major issue in hardware engineering.

4. Explain how you would bring up and debug a newly assembled prototype board.

Why they ask: Bring-up is a practical test of hardware engineers' methodology.

5. How do you approach EMC for a product, and what would you do if it fails radiated emissions at the test house?

Why they ask: EMC failure is a common and costly hardware problem, and they want practical knowledge.

6. You have found a design error on a board that is already in production. What do you do?

Why they ask: They are testing ownership, escalation and impact analysis.

7. Tell me about a time you designed a piece of hardware from specification to working prototype. What challenges did you face?

Why they ask: They want to see end-to-end ownership of a hardware design.

8. Why did you choose hardware engineering rather than software, and what do you enjoy about it?

Why they ask: They want to understand genuine motivation for hardware.

A sample answer to question 1

Walk me through how you design a power supply for a new board, from requirements to component selection.

I begin by listing every load, with minimum, typical and maximum current for each rail, plus input voltage range, efficiency and noise requirements, and any standards, such as EMC limits. Then I choose the architecture. A linear regulator or LDO suits low current and noise-sensitive analogue rails but wastes power as heat, whereas a switching buck or boost converter gives high efficiency but adds ripple and EMI. I often use a buck for the main conversion and an LDO to post-regulate sensitive rails. I select controller ICs from datasheet calculations or manufacturer tools like TI WEBENCH, then size the inductor for ripple current and saturation, output capacitors for ripple and transient response, accounting for ESR and DC bias derating on ceramics. I plan power sequencing, protection like overcurrent, overvoltage and reverse polarity, and thermal dissipation. I verify with LTspice simulation, then measure real ripple, efficiency and load transient response on the prototype using a properly grounded oscilloscope probe.

Common mistake to avoid: Ignoring capacitor DC bias derating; no protection or sequencing

Want the rest?

Full model answers, key points and common mistakes for all 16 questions are on the Hardware Engineer interview questions page. The first five are free, no sign-up needed.