Roles they hire for
- SDK and Zephyr driver engineer
- Security software engineer for nRF Connect SDK
- Connectivity firmware engineer (BLE, Thread, Matter)
What they emphasise
- Zephyr drivers and new APIs in the open-source nRF Connect SDK
- BLE, Thread, Matter, Wi-Fi and LTE-M products
- Trusted Firmware-M and Mbed TLS integration
- Low-power devices and hardware debugging
Brush up on
Zephyr devicetree and driversnRF Connect SDKBLE GATTThread and MatterTF-MMbed TLSPower profiling
How the rounds usually run
A typical silicon vendor loop for embedded roles. Companies vary by team and seniority.
Online assessment or screen
- C output prediction, pointers and bit manipulation
- Digital logic and OS basics
- For experienced hires, often a recruiter and hiring-manager screen instead
Example: What does this print: an unsigned char set to 200 plus 100, printed as an integer?
Technical 1: C and embedded fundamentals
- Pointers, volatile, const, alignment and endianness
- Interrupts, stacks and memory layout
- Live C coding on bit fields, ring buffers or string handling
Example: Implement a lock-free single-producer, single-consumer ring buffer.
Technical 2: Drivers and architecture
- Designing a peripheral driver and its API
- DMA, caches and interrupt priorities
- RTOS internals and debugging stories
Example: Design a SPI driver that supports blocking, interrupt and DMA modes behind one API.
Technical 3 or hiring manager: system design and projects
- Deep dive into a past project and your design choices
- System-level trade-offs: power, memory, performance
- Sometimes a short presentation on a project
Example: Walk through the hardest bug you've fixed, and what you changed in the process afterwards.
HR and behavioural
- Motivation, teamwork and conflict
- Relocation, notice period and compensation
Example: Tell me about a time you disagreed with a design decision.
Practice questions
Original questions written for Nordic Semiconductor's focus areas, not leaked ones.
- A BLE sensor must last two years on a coin cell. Walk through your power budget and the connection parameters you'd choose.
- Write the outline of a Zephyr sensor driver: devicetree binding, init, and the API it exposes.
- Where would you keep keys on a Cortex-M33 with TrustZone, and how does the application use them without seeing them?
- BLE throughput is far below expectations. Which parameters and code paths do you check first?
- How would you design firmware update over BLE so a dropped connection never bricks the device?
Your prep playlist
Design rounds to practise
Sources
Take an AI mock round styled on Nordic Semiconductor, with follow-ups that probe what you missed.
Start a mock round