Software Engineer III

At Sierra Space, we build the missions and systems that keep our world secure in the domain above Earth.

Sierra Space team members share a spirit of innovation and collaboration and a belief that we can deliver on the boldest missions in space today. Together with our customers, we aim to safeguard our nation, sustain human presence in space, and secure the freedom of operations in low Earth orbit and beyond.

Our success is measured by the trust of those who rely on what we build and deliver, and our technologies keep the United States and its allies mission‑ready throughout space.

We are mission‑driven, and together, we are an extraordinary team.

The Software Engineer III role involves designing, developing, and testing software applications for space systems and technologies. This advanced position requires expertise in at least one programming language, an advanced understanding of software development principles, and the ability to design and architect complex software systems. You will write clean, maintainable code, collaborate with team members to understand project requirements, and contribute to the development of innovative software solutions.

Additionally, you will mentor and guide other engineers, providing technical leadership and support.

In this role, you will design, develop, and test software applications for space systems and technologies while writing clean, maintainable code that adheres to best practices and coding standards. You will architect and implement complex software systems to meet project requirements and collaborate with team members to understand project needs, contributing to the development of effective software solutions. Utilizing version control systems such as Git, you will manage code changes and work collaboratively with team members.

You will participate in code reviews to ensure code quality and adherence to development standards, troubleshoot and resolve software‑related issues in a timely manner, and document software configurations, processes, and procedures for future reference. Staying current with industry trends and advancements in software development and space technologies will be essential, and you will mentor and guide other engineers, providing technical leadership and support to foster growth and collaboration within the team.

Our mission is driven by an unyielding commitment to advancing space‑based technology in service of our customers and safeguarding national security. We seek individuals who are passionate about innovating beyond boundaries and relentlessly pursuing solutions that protect, preserve and empower—and to join us in this critical mission.

We’re looking for team members who align with our values, mission, and goals—while also meeting the minimum qualifications below. The preferred qualifications are a bonus, not a requirement.

• Requires bachelor’s degree in a related field (or equivalent work experience in lieu of degree or master’s +3 yrs experience).
• Typically, 5+ years of related experience.
• Expertise in one to multiple programming languages and advanced understanding of software development principles.
• Ability to design and architect complex software systems.
• Experience with different software development methodologies such as Agile and Scrum/Kanban.
• Strong problem‑solving skills.
• Ability to mentor and guide other engineers.
• The ability to obtain and maintain a U.S. Security Clearance is required

• Strong technical understanding of C++ and Object‑Oriented Programming
• Experience implementing client‑server applications using socket I/O using TCP/UDP.
• Experience implementing loosely coupled applications using PUB/SUB messaging
• Familiarity with Open Standards such as CCSDS, C2MS, Open Mission Systems (OMS), and Universal C2 Interface (UCI)
• Experience with spacecraft flight software development
• Experience developing mission management and/or payload control software
• Demonstrated experience leading a team developing software
• Experience with software tools for requirements tracking, code reviews, static analysis, library and artifact repository, and automated build
• Knowledge…