What is a Embedded Engineer at Astranis?

As an Embedded Engineer at Astranis, you are building the critical software that brings next-generation micro-geostationary satellites to life. This role sits at the absolute core of the company's mission to connect the unconnected. You will write the code that manages spacecraft subsystems, processes high-throughput network traffic in orbit, and rigorously tests hardware before it ever leaves the ground.

The impact of this position is immense. Because Astranis operates in a fast-paced, vertically integrated environment, you are not just writing isolated firmware. You are directly responsible for the reliability, performance, and safety of multi-million-dollar space assets. Whether you are developing low-level flight software, engineering network routing protocols for space-to-ground communication, or building production test infrastructure to validate flight hardware, your code ensures mission success in one of the harshest environments imaginable.

Expect a highly collaborative, cross-functional engineering culture. You will work shoulder-to-shoulder with hardware designers, FPGA engineers, and payload specialists. The complexity of the problems you will solve requires a deep understanding of the boundary between hardware and software, a relentless focus on system reliability, and the agility to iterate quickly without compromising quality.

Getting Ready for Your Interviews

Preparing for an interview at Astranis requires more than just brushing up on syntax; you need to demonstrate a holistic understanding of embedded systems from the bare metal up to the application layer. Interviewers want to see how you think when the hardware behaves unexpectedly and how you architect software that cannot fail.

Focus your preparation on these key evaluation criteria:

• Firmware & Systems Engineering – You must exhibit a deep, intuitive grasp of C/C++, memory management, and real-time operating systems (RTOS). Interviewers will evaluate your ability to write highly efficient, deterministic code that respects strict resource constraints.
• Hardware-Software Co-design – You will be tested on your ability to read schematics, understand component datasheets, and communicate effectively with hardware engineers. Demonstrating experience with board bring-up and hardware debugging tools (like oscilloscopes and logic analyzers) is crucial.
• Mission-Critical Problem Solving – Spacecraft cannot be easily rebooted or patched once deployed. You must show how you design for fault tolerance, handle edge cases, and systematically debug complex system-level issues.
• Adaptability & Ownership – Astranis values engineers who take extreme ownership of their systems. You should be prepared to discuss how you have driven projects from initial concept through production, adapting to shifting requirements along the way.

Interview Process Overview

The interview process for an Embedded Engineer at Astranis is rigorous, practical, and highly focused on real-world engineering challenges. You will typically begin with a recruiter screen to align on your background, role interests (such as Network Software vs. Production Test), and compensation expectations. This is followed by a technical screen with a hiring manager or senior engineer, which usually involves a deep dive into your past projects and a live coding exercise focused on embedded C/C++ fundamentals, bit manipulation, or basic hardware interfacing.

If you advance, you will be invited to a comprehensive onsite or virtual panel. This stage is designed to test the limits of your technical depth and your ability to collaborate. You will face specialized rounds covering system architecture, advanced coding, hardware debugging, and behavioral alignment. Astranis interviewers rely heavily on practical scenarios rather than abstract puzzles; they want to see how you would troubleshoot a malfunctioning peripheral or architect a test suite for a new flight computer.

Expect an environment that is challenging but collaborative. Interviewers will often provide hints or pivot the constraints of a problem to see how you adapt. They are looking for engineers who remain calm under pressure, communicate their assumptions clearly, and drive toward pragmatic, robust solutions.

This timeline illustrates the typical progression from your initial recruiter conversation through the technical screens and the final multi-round panel. Use this visual to pace your preparation, ensuring you are ready for both the rapid-fire technical questions early on and the deep architectural and behavioral discussions required during the final stages. Minor variations may occur depending on whether you are interviewing for a senior role, network software, or production test software.

Deep Dive into Evaluation Areas

Embedded C/C++ and RTOS Fundamentals

This is the bedrock of your technical evaluation. Interviewers will probe your mastery of the C/C++ languages specifically within the context of resource-constrained, real-time environments. Strong performance means writing clean, deterministic code without relying on dynamic memory allocation, and demonstrating a flawless understanding of pointers, volatile variables, and bitwise operations.

Be ready to go over:

• Memory Management – Stack vs. heap, memory maps, alignment, and the dangers of memory fragmentation in long-running systems.
• Concurrency and Interrupts – Writing safe Interrupt Service Routines (ISRs), managing race conditions, and using mutexes, semaphores, and queues in an RTOS environment.
• Bit Manipulation – Setting, clearing, and toggling bits, packing and unpacking data structures, and handling endianness.
• Advanced concepts (less common) – Custom bootloaders, memory protection units (MPUs), and compiler optimization flags.

Example questions or scenarios:

• "Implement a circular buffer in C that is safe to be read from a main loop and written to by an ISR."
• "Explain the volatile keyword and provide three distinct scenarios where it must be used."
• "Write a function to reverse the bits of a 32-bit integer as efficiently as possible."

Hardware Interaction and Board Bring-up

Because you are building physical spacecraft and test equipment, you must prove you can bridge the gap between software and hardware. Interviewers want to know that you can read a datasheet, configure a microcontroller's peripherals, and debug a failing communication bus using standard lab equipment.

Be ready to go over:

• Communication Protocols – Deep understanding of I2C, SPI, UART, CAN, and Ethernet, including their physical layers and timing constraints.
• Peripheral Configuration – Setting up DMA, timers, ADCs, and DACs from scratch.
• Debugging Techniques – How you use oscilloscopes, logic analyzers, and multimeters to prove whether a bug is in the software or the hardware.
• Advanced concepts (less common) – Signal integrity issues, clock domains, and basic FPGA interfacing.

Example questions or scenarios:

• "Walk me through the exact steps you would take to bring up a custom PCB with a new microcontroller and an external SPI flash memory."
• "You are reading data over I2C and occasionally getting corrupted bytes. How do you isolate the root cause?"
• "Design a driver architecture for a sensor that takes 500ms to sample, ensuring the CPU isn't blocked during that time."

Networking and Test Infrastructure

Depending on your specific track (Network Software or Production Test), you will be evaluated on your ability to move data reliably or validate hardware at scale. Strong candidates will show they can architect robust Python-based test frameworks or implement high-throughput network stacks that survive high-latency, lossy environments.

Be ready to go over:

• Network Protocols – TCP/IP, UDP, routing algorithms, and custom packet structures.
• Test Automation – Using Python to control test equipment (SCPI), inject faults, and automate hardware-in-the-loop (HITL) testing.
• System Architecture – Designing scalable software that can test hundreds of boards simultaneously or route gigabits of data through a satellite payload.
• Advanced concepts (less common) – Network simulation, RF fundamentals, and Linux kernel networking.

Example questions or scenarios:

• "Design an automated test suite for a newly manufactured power supply board. What hardware and software do you need?"
• "Explain how TCP handles packet loss and why it might be problematic over a high-latency satellite link."
• "Write a Python script to parse a binary log file and extract specific telemetry frames."

Key Responsibilities

As an Embedded Engineer at Astranis, your day-to-day work is highly dynamic and deeply tied to the physical hardware. If you are on the flight software team, you will spend your time writing and optimizing the C/C++ firmware that controls satellite attitude, manages power distribution, and monitors system health. You will frequently compile your code, flash it onto engineering models, and monitor telemetry to verify its behavior under simulated space conditions.

If you are focused on Network Software, your responsibilities will pivot toward implementing and optimizing routing protocols, managing data flow through the satellite's payload, and ensuring secure, high-throughput communication between the spacecraft and ground stations. You will collaborate closely with FPGA engineers to offload critical network processing to hardware, ensuring maximum efficiency.

For those in the Hardware/Production Test Software track, your primary deliverable is confidence. You will architect the Python-based automated test frameworks that validate every single piece of hardware before it is integrated into the satellite. This involves writing drivers for custom test fixtures, automating lab equipment, and analyzing massive datasets to catch manufacturing defects or design flaws early in the production cycle. Regardless of your specific team, you will spend a significant portion of your week in the lab, probing boards, reading schematics, and collaborating with cross-functional teams to solve complex integration challenges.

Role Requirements & Qualifications

To thrive as an Embedded Engineer at Astranis, you need a blend of low-level software expertise, hardware intuition, and a proactive, problem-solving mindset. The company looks for engineers who are not afraid to dig into an unfamiliar datasheet or trace a signal on a schematic to find the root cause of an issue.

• Must-have skills – Exceptional proficiency in C and C++ for embedded systems. Deep understanding of RTOS concepts, concurrency, and memory management. Hands-on experience with hardware communication protocols (SPI, I2C, UART) and lab debugging tools (oscilloscopes, logic analyzers). For test-focused roles, strong Python skills for automation are mandatory.
• Experience level – Mid-level to senior roles typically require 4 to 8+ years of experience in embedded software, firmware, or hardware test engineering. Experience taking a product through the full lifecycle—from prototype to production—is highly valued.
• Soft skills – Strong cross-functional communication is essential. You must be able to explain software constraints to hardware engineers and vice versa. Extreme ownership, adaptability, and the ability to thrive in a fast-paced, sometimes ambiguous startup environment are critical.
• Nice-to-have skills – Previous experience in the aerospace, satellite, or automotive industries. Familiarity with Linux kernel drivers, Yocto, FPGA interfacing, or advanced networking protocols.

Common Interview Questions

The questions below represent the types of technical and behavioral challenges you will encounter during the Astranis interview process. They are designed to test not just your knowledge, but your approach to problem-solving, debugging, and system design. Focus on the underlying concepts rather than memorizing specific answers.

Firmware & RTOS Fundamentals

These questions test your mastery of C/C++ and your ability to write safe, efficient code for constrained environments.

• Implement a thread-safe queue using mutexes and semaphores.
• Explain the difference between an inline function and a macro. When would you use each?
• Write a C function to count the number of set bits in a 32-bit integer.
• How do you prevent priority inversion in an RTOS?
• Describe the boot sequence of an ARM Cortex-M microcontroller from power-on to main().

Hardware Interaction & Debugging

These questions evaluate your ability to interface with physical components and troubleshoot complex system issues.

• You are communicating with a sensor over SPI, but reading all zeros. Walk me through your debugging process.
• Explain how DMA works and provide an example of when you would use it instead of interrupt-driven I/O.
• Given a specific component datasheet, how would you configure the microcontroller's registers to initialize it?
• How do you handle debouncing a physical button press in software?
• Design a system to monitor the temperature of 10 different components on a board and trigger an alert if any exceed a threshold.

Networking & Test Automation (Role Dependent)

These questions focus on your ability to move data reliably or build robust validation infrastructure.

• How would you design a custom protocol to send telemetry data over a lossy UART connection?
• Write a Python script to interface with a power supply over a serial connection, set a voltage, and read the current.
• Explain the OSI model and describe where a custom MAC protocol would fit in.
• How do you structure a test framework to handle hundreds of asynchronous hardware tests simultaneously?
• Describe how you would implement a firmware over-the-air (OTA) update mechanism safely.

Behavioral & Past Experience

These questions assess your cultural fit, ownership, and ability to work in a high-stakes environment.

• Tell me about the most difficult hardware/software integration bug you have ever solved.
• Describe a time when you had to push back on a hardware design change because of software constraints.
• How do you prioritize tasks when working on a critical path for a launch or production deadline?
• Tell me about a project where you had to learn a completely new technology or protocol on the fly.
• Why are you interested in the space industry, and why Astranis specifically?

Frequently Asked Questions

Q: How deep do I need to go into hardware during the technical screens? You are not expected to design complex analog circuits, but you must be comfortable reading schematics, understanding basic electronic components (resistors, capacitors, pull-ups), and explaining how you would use lab equipment to verify the signals your software is generating.

Q: Is prior aerospace or satellite experience required? No. While aerospace experience is a nice bonus, Astranis frequently hires engineers from automotive, consumer electronics, medical devices, and traditional networking backgrounds. They care about your engineering fundamentals and your ability to build reliable, mission-critical systems.

Q: What is the difference between the Network Software and Production Test roles? The Network Software role focuses heavily on data routing, payload management, and high-throughput communication protocols (often involving Linux and advanced networking concepts). The Production Test role focuses on writing Python-based automation frameworks to validate physical hardware, requiring deep knowledge of test instruments and hardware-in-the-loop systems.

Q: Where are these roles located, and what is the working style? These roles are based in San Francisco, CA. Because the work is deeply tied to physical hardware, lab equipment, and satellite integration, these are primarily onsite roles. You must be comfortable working in an office and lab environment.

Other General Tips

• Think out loud and state your assumptions: When given a coding or system design problem, do not just start writing silently. Explain your thought process, clarify the constraints (e.g., "Are we assuming a 32-bit architecture?"), and discuss the trade-offs of your approach.
• Brush up on your bitwise math: You will almost certainly be asked to manipulate bits, pack data, or interact with memory-mapped registers. Be fast and flawless with &, |, ^, ~, <<, and >>.

• Know your resume inside and out: Be prepared to draw block diagrams of any system you list on your resume. Interviewers will pick a specific project and drill down until they reach the limits of your knowledge to understand exactly what you contributed.
• Ask hardware-minded questions: At the end of your interviews, ask questions that show you understand the domain. Ask about their testing philosophy, how they handle radiation mitigation in software, or what their typical board bring-up process looks like.

Summary & Next Steps

Securing an Embedded Engineer role at Astranis is an opportunity to push the boundaries of what is possible in commercial spaceflight. You will be joining a team of brilliant, driven engineers who are fundamentally changing global connectivity. The work is demanding, the standards for reliability are astronomical, and the hardware-software challenges are incredibly rewarding.

To succeed in this interview process, focus on solidifying your embedded C/C++ fundamentals, practicing your hardware debugging logic, and preparing clear, detailed narratives about your past projects. Remember that interviewers are looking for colleagues they can trust to write code that survives the vacuum of space. Be confident, communicate clearly, and lean into your practical, hands-on engineering experience.

This compensation data reflects the base salary ranges for various Embedded Engineer positions at the San Francisco headquarters. The wide range ($115,000 to$260,000 USD) accounts for differences in seniority (e.g., standard vs. Senior) and specific sub-disciplines (e.g., Production Test vs. Flight/Network Software). When evaluating your offer, remember to consider the full compensation package, including equity in a high-growth aerospace startup.

You have the technical foundation and the problem-solving skills required to excel in this process. Continue to explore additional interview insights and resources on Dataford to refine your approach. Trust your preparation, embrace the technical challenges, and get ready to help build the future of space-based internet.