Hardware and Electrical Engineering Interviews: What to Expect and How to Prepare

Hardware engineering interviews, whether for power electronics, PCB design, embedded hardware or test engineering, look very different from software interviews. You are less likely to get a list of puzzle-style coding problems and more likely to face circuit questions, design discussions, and a detailed review of projects you have built. Here is how to prepare for each stage. Phone screens and technical prescreens Early rounds usually test fundamentals and your project experience. Expect questions such as: explain how a buck converter works, why do we use decoupling capacitors, what is the difference between a MOSFET and a BJT in a switching application, or how would you choose an op-amp for a sensor front end. Review Ohm's law, Kirchhoff's laws, RC and RLC behaviour, transistor operation, and basic digital logic. Answer with intuition first, then equations. Circuit analysis on the spot Interviewers often draw a circuit and ask you to find a voltage, a current, or the frequency response. Talk through your approach: identify the topology, simplify where possible, and check limiting cases, such as what happens at DC or at very high frequency. Saying your assumptions out loud lets the interviewer correct you early instead of watching you go down a wrong path. Design questions A typical prompt is: design a power supply that converts 12 V to 3.3 V at 2 A for a microcontroller board. A strong answer covers the choice between a linear regulator and a switching converter, efficiency and heat, component selection, layout considerations, protection, and how you would test it. For signal integrity roles, expect questions about impedance control, termination, return paths and EMC. Project deep dives This is often the deciding round. Choose two projects you know inside out. Be ready to explain the requirements, why you chose each major component, what went wrong, how you debugged it with an oscilloscope or logic analyser, and what you would change in the next revision. Bring photos or schematics if the format allows. Honest stories about failures and fixes are more convincing than polished summaries. Coding and tools Many hardware roles still include some coding, often Python for test automation, C for firmware, or Verilog for FPGA work. Be comfortable writing a small script to process measurement data. Mention the tools you have used, such as Altium, KiCad, LTspice, or MATLAB. Behavioural questions Hardware teams work under tight schedules and shared responsibility. Prepare STAR examples about meeting a deadline, working with firmware or mechanical engineers, and handling a design that failed testing. Remote technical rounds Many first rounds are now on video with a shared whiteboard. Practise drawing circuits neatly on a digital whiteboard and explaining as you draw. Linkjob AI (https://linkjob.ai) gives real-time help during live job interviews and technical interviews, which some hardware candidates use to keep their explanations structured during long technical loops. Questions to ask Ask about the product lifecycle, how many board spins are typical, what lab equipment the team uses, and how hardware and firmware collaborate. These show you understand what the work actually involves.