Embedded Firmware Intern (Summer 2027)
Posted Sep 25, 2026 · We last checked this listing on Oct 6, 2026
Likely interview questions for this role
Written from this job description, not a generic list. Each one notes what the interviewer is really checking.
About your past
Tell me about a firmware or microcontroller project you built. What did the code have to talk to?
What they are checking: Whether they have actually written code that drives real hardware, not just software that runs on a laptop.
Tell me about a time you were stuck on a bug for a long time. What finally got you unstuck?
What they are checking: Whether they persist, ask for help at the right time, and learn from the process rather than giving up.
How do you keep your code readable and safe when someone else will pick it up after your internship ends?
What they are checking: Whether they use version control, comments and clear structure so their summer work survives after they leave.
What interests you about writing firmware for water and plumbing products?
What they are checking: Whether they have thought about this company's products and why connected water devices are an engineering challenge.
What would you do
Your code works on the bench but the device resets randomly in testing. How do you start tracking that down?
What they are checking: Whether they debug methodically with tools and logs instead of guessing, and consider hardware causes like power or watchdogs.
About the work
What is the difference between polling a sensor and using an interrupt, and when would you pick each?
What they are checking: Whether they understand the basic timing and power tradeoffs that every embedded system design depends on.
Why might you use the volatile keyword in C on a microcontroller?
What they are checking: Whether they know how compilers treat memory shared with hardware or interrupts, a classic source of embedded bugs.
Products like touchless faucets and bottle fillers run on batteries or limited power. How would you write firmware to save power?
What they are checking: Whether they think about sleep modes and duty cycles, which decide how long a battery product lasts in the field.
How would you explain SPI, I2C and UART to a classmate, and when would you choose one over the others?
What they are checking: Whether they know the common serial buses well enough to read a datasheet and wire up a part on their own.
What tools have you used to debug embedded code, like a debugger, logic analyzer or oscilloscope?
What they are checking: Whether they can see what the hardware is really doing instead of relying only on print statements.
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Practice this out loudThe full job description
As published by Zurn Elkay.