Debugging & System Integration

Writing code is only half the battle; debugging it on physical hardware is where true embedded expertise is shown.

Be ready to go over:

• Hardware Tools – Effective use of logic analyzers, oscilloscopes, and JTAG/SWD debuggers.
• Software Debugging – Analyzing core dumps, stack traces, and register states to find memory corruption or deadlocks.
• Defensive Programming – Implementing assertions, error logging, and fail-safe states.

Example scenarios:

• "Your system occasionally resets when a high-power peripheral turns on. Walk me through how you would determine if this is a hardware power issue or a software crash."
• "How do you debug a hard fault exception on an ARM Cortex-M processor?"

As an Embedded Engineer at Dexcom, your daily work will revolve around bringing robust firmware solutions to life. You will be responsible for the entire software lifecycle of embedded systems, from initial prototyping to post-market support.

• Firmware Design and Implementation – Writing modular, maintainable, and highly optimized C/C++ code for medical devices.
• Hardware Bring-up and Driver Development – Collaborating with hardware engineers to test new board designs, write low-level drivers, and verify peripheral functionality.
• System Integration and Testing – Integrating wireless stacks (such as BLE), sensor algorithms, and power management schemes into a cohesive system.
• Regulatory Compliance and Documentation – Writing detailed design specifications, test plans, and code documentation in accordance with medical device software standards (such as IEC 62304).
• Cross-Functional Collaboration – Working closely with mobile app developers, cloud engineers, and product managers to ensure seamless end-to-end system operation.

To be competitive for this position, you must possess a strong foundation in both electrical engineering and computer science concepts.

• Must-have technical skills – Proficient in C programming, experience with ARM Cortex-M or similar microcontrollers, familiarity with RTOS concepts, and hands-on experience with hardware debugging tools (oscilloscopes, logic analyzers).
• Nice-to-have skills – Experience with Bluetooth Low Energy (BLE), knowledge of medical device software development standards (IEC 62304), and familiarity with python for test automation.
• Experience level – Typically requires a Bachelor's degree in Electrical Engineering, Computer Engineering, Computer Science, or a related field, along with relevant industry experience or highly technical academic project work.
• Soft skills – Strong technical communication, attention to detail, a collaborative mindset, and the ability to work effectively in a regulated, safety-critical environment.

Q: How technical is the interview process for an Embedded Engineer at Dexcom? A: The process is highly technical and focuses heavily on fundamental embedded concepts. You should expect in-depth questions about C programming, microcontroller architectures, and hardware debugging rather than generic behavioral questions.

Q: How much preparation time is recommended? A: Candidates typically benefit from 2 to 3 weeks of targeted preparation. Focus on reviewing C programming concepts (pointers, memory, bit manipulation), embedded system architectures, and the specific details of your past projects.

Q: What is the work culture like for the engineering team? A: The culture is highly collaborative, quality-focused, and mission-driven. Engineers are passionate about the impact of their work on patient health, which fosters a meticulous and supportive engineering environment.

Q: Are the interviews conducted in person or virtually? A: Depending on the location and team, the initial rounds are virtual, while the final panel round may be conducted onsite at a Dexcom office (such as San Diego, CA) or via a comprehensive virtual panel.

• Review Your Past Code – Be ready to explain the architecture, design choices, and debugging processes of your previous projects or school work in precise detail. Interviewers often ask deep, specific questions about your resume.
• Think Out Loud – During coding and system design exercises, explain your thought process clearly. This helps interviewers understand your analytical approach, even if you do not arrive at the perfect solution immediately.
• Highlight Safety and Reliability – Whenever you discuss design choices, emphasize how you ensure code reliability, handle errors, and prevent system failures. This alignment with medical device standards is highly valued.
• Ask Clarifying Questions – When presented with an ambiguous technical scenario, ask questions to constrain the problem (e.g., "What is the available memory?", "What are the power constraints?"). This demonstrates structured engineering thinking.

Securing an Embedded Engineer role at Dexcom is an opportunity to work on cutting-edge wearable technology that directly improves human lives. The interview process is rigorous but fair, focusing on your core technical strengths, low-level programming expertise, and problem-solving capabilities.

To maximize your chances of success, dedicate your preparation to mastering embedded C, understanding hardware-software interfaces, and being able to speak articulately about your past technical decisions. Approach every problem with a focus on optimization, reliability, and safety.

The compensation data above reflects the competitive packages Dexcom offers to attract top-tier engineering talent. When evaluating an offer, consider the complete compensation package, including base salary, bonuses, and equity, alongside the immense professional growth and impact of working in the medical device industry. You can explore more detailed interview insights and preparation resources on Dataford to help you ace your upcoming interviews. Good luck!