1. What is an Embedded Engineer at Collins Aerospace?

As an Embedded Engineer at Collins Aerospace, you are at the forefront of designing mission-critical systems that keep the aerospace and defense sectors safe, reliable, and technologically advanced. This role is not just about writing code; it is about bridging the gap between hardware and software in environments where failure is not an option. Whether you are working on advanced avionics, secure communications, or next-generation space systems out of hubs like El Segundo, CA, your work directly impacts national security and global aviation infrastructure.

For the Principal Crypto Embedded Software Engineer track, the stakes are even higher. You will be responsible for architecting and implementing cryptographic solutions, secure boot mechanisms, and tamper-resistant software that protect sensitive data from sophisticated threats. You will operate at the intersection of embedded systems and cybersecurity, ensuring that hardware security modules (HSMs) and cryptographic algorithms are flawlessly integrated into resource-constrained environments.

This position offers a unique blend of extreme technical depth and strategic leadership. Because you are building products with lifecycles that span decades, you will tackle complex challenges related to scale, real-time performance, and rigorous compliance standards. Expect a challenging but deeply rewarding environment where your technical decisions shape the future of secure aerospace engineering.

2. Common Interview Questions

3. Getting Ready for Your Interviews

Preparing for an interview at Collins Aerospace requires a strategic approach. You must demonstrate not only your technical prowess but also your alignment with the rigorous safety and security standards of the aerospace industry.

Technical Mastery & Domain Expertise – You will be evaluated on your deep understanding of embedded systems, C/C++ programming, and real-time operating systems (RTOS). For crypto-focused roles, interviewers will heavily scrutinize your knowledge of cryptographic algorithms, secure key management, and hardware-software integration. You can demonstrate strength here by confidently discussing low-level memory management, interrupt handling, and applied cryptography.

Problem-Solving & Architecture – At the Principal level, it is not enough to just write functional code. Interviewers want to see how you approach complex, ambiguous system-level challenges. You will be assessed on your ability to design secure, scalable architectures while balancing constraints like memory, power, and processing speed. Show your strength by thinking out loud, outlining edge cases, and defending your architectural trade-offs.

Safety, Security, & Process Adherence – Collins Aerospace operates in a highly regulated environment. You will be evaluated on your respect for rigorous development processes, such as DO-178C for airborne systems or strict cryptographic compliance standards. Demonstrate this by highlighting your experience with unit testing, static analysis, code reviews, and secure coding practices.

Leadership & Mentorship – As a Principal Engineer, you are expected to be a force multiplier for your team. Interviewers will look for evidence of how you influence cross-functional teams, mentor junior engineers, and drive technical consensus. Frame your past experiences around how you led initiatives, resolved technical disputes, and communicated complex ideas to non-technical stakeholders.

4. Interview Process Overview

The interview process at Collins Aerospace is thorough and designed to assess both your deep technical capabilities and your fit within a highly structured, compliance-driven engineering culture. The process typically begins with a recruiter screen to verify your background, clearance eligibility, and basic qualifications. This is followed by a technical screen with a hiring manager or senior engineer, which focuses on your resume, past projects, and high-level embedded concepts.

If you advance, you will be invited to a comprehensive panel interview, which may be conducted virtually or onsite. This stage usually consists of several sessions spanning technical deep dives, architecture and system design, and behavioral evaluations. Unlike consumer tech companies that heavily index on LeetCode-style algorithm puzzles, Collins Aerospace prioritizes practical, domain-specific problem solving. You will face questions about bare-metal programming, RTOS behavior, cryptography, and real-world debugging scenarios.

The company places a strong emphasis on collaboration and communication. Throughout the process, interviewers will gauge how well you articulate your thought process and how you handle pushback. They want to see that you can work effectively with hardware engineers, systems engineers, and program managers to deliver complex, secure systems.

This visual timeline outlines the typical stages of your interview journey, from the initial recruiter screen to the final comprehensive panel. Use this to pace your preparation—focus first on articulating your past experience and high-level concepts for the initial screens, then transition into deep technical review and system design practice for the final rounds. Keep in mind that for defense-related roles, the timeline may occasionally stretch due to clearance verifications or specific program requirements.

5. Deep Dive into Evaluation Areas

To succeed in your interviews, you must be prepared to demonstrate expertise across several core technical and behavioral domains.

Embedded C/C++ and Low-Level Programming

At the heart of any embedded role is your ability to write efficient, safe, and predictable code. Interviewers will test your mastery of C and C++, focusing on concepts that are critical for resource-constrained environments. Strong candidates will effortlessly navigate memory management without relying on dynamic allocation, understand the nuances of the compilation process, and write code that interacts directly with hardware registers.

Be ready to go over:

• Pointers and Memory – Deep understanding of pointer arithmetic, function pointers, and memory-mapped I/O.
• Volatile and Interrupts – How and why to use the volatile keyword, and best practices for writing Interrupt Service Routines (ISRs).
• Concurrency in C/C++ – Managing shared resources, race conditions, and atomic operations without an OS.
• Advanced concepts (less common) – Custom linker scripts, assembly language integration, and compiler optimization flags.

Example questions or scenarios:

• "Write a macro to set, clear, and toggle a specific bit in a hardware register."
• "Explain what happens in the system from the moment power is applied to when main() is called."
• "How would you debug a hard fault on an ARM Cortex-M processor?"

Cryptography and Secure Systems

For the Principal Crypto Embedded Software Engineer role, this is a make-or-break evaluation area. You must prove that you can design and implement systems that withstand sophisticated cyber threats. Interviewers will look for a solid foundation in applied cryptography and experience integrating these concepts into embedded hardware.

Be ready to go over:

• Symmetric vs. Asymmetric Crypto – Appropriate use cases for AES, RSA, ECC, and the performance trade-offs in embedded systems.
• Secure Boot and Trust Anchors – Designing a chain of trust from immutable ROM to the application layer.
• Key Management – Secure generation, storage, and rotation of cryptographic keys using Hardware Security Modules (HSMs) or secure elements.
• Advanced concepts (less common) – Side-channel attack mitigation, Post-Quantum Cryptography (PQC) readiness, and FIPS 140-3 compliance.

Example questions or scenarios:

• "Walk me through the architecture of a secure bootloader for an avionics communication module."
• "How would you securely store a private key on a microcontroller that does not have a dedicated secure enclave?"
• "Explain the difference between encryption, hashing, and digital signatures, and provide an embedded use case for each."

RTOS and Hardware Integration

Embedded engineers at Collins Aerospace rarely work in isolation from the hardware. You will be evaluated on your ability to orchestrate complex tasks using a Real-Time Operating System and your familiarity with standard hardware interfaces. Strong performance here means showing you can debug issues with an oscilloscope just as well as you can with a software debugger.

Be ready to go over:

• RTOS Fundamentals – Task scheduling, priority inversion, mutexes, semaphores, and message queues.
• Communication Protocols – Deep knowledge of SPI, I2C, UART, CAN, and Ethernet.
• Hardware Debugging – Using logic analyzers, JTAG, and oscilloscopes to verify software-hardware timing.
• Advanced concepts (less common) – Direct Memory Access (DMA) configuration, FPGA-to-processor communication, and multi-core RTOS synchronization.

Example questions or scenarios:

• "Describe a scenario where priority inversion occurs and explain how a priority inheritance protocol resolves it."
• "You are reading data from a sensor via SPI, but the data is occasionally corrupted. How do you troubleshoot this?"
• "How do you decide whether to use an interrupt or polling for a specific hardware peripheral?"

System Design and Leadership

As a Principal Engineer, you are expected to lead the technical direction of major projects. This area evaluates your ability to design robust architectures from scratch and your capacity to guide a team through complex technical challenges. Interviewers want to see a balance of visionary thinking and practical, ground-level execution.

Be ready to go over:

• Architecture Trade-offs – Balancing power consumption, memory footprint, processing speed, and security.
• Cross-Functional Collaboration – How you work with hardware teams to define pinouts, power states, and board bring-up processes.
• Mentorship and Influence – Strategies for elevating the technical bar of your team through code reviews and architectural guidance.
• Advanced concepts (less common) – Designing for DO-178C certification, fault-tolerant system design, and redundancy management.

Example questions or scenarios:

• "Design the software architecture for a secure, over-the-air (OTA) firmware update system."
• "Tell me about a time you disagreed with a hardware engineer about a system design. How did you resolve it?"
• "How do you ensure that your team writes code that is both secure and compliant with aerospace standards?"