Software Architect

Fathom5

$130K — $155K *
Aerospace & Defense
8 - 10 years of experience
Job Overview by Ladders

Qualifications

  • 8+ years of software engineering experience with a focus on systems design and implementation.
  • Proven architecture ownership for a shipped system in real-world conditions.
  • Expertise in a statically typed systems language, preferably Go.
  • In-depth knowledge of Linux systems and debugging tools.
  • Experience with AI Native development and coding tools.
  • Design-level competence in container orchestration (Kubernetes) and distributed systems fundamentals.
  • Strong written and verbal communication skills, capable of producing detailed design documents.

Responsibilities

  • Own the architecture of TempestOS subsystems, including design and implementation.
  • Design for AI Native development with contextual oversight from human developers.
  • Produce detailed design artifacts for developer implementation without ambiguity.
  • Incorporate security as a foundational design element rather than a post-design consideration.
  • Review design proposals before implementation, ensuring feasibility and adherence to standards.
  • Mentor junior developers, focusing on their growth and understanding of complex designs.
  • Contribute to the codebase, prototyping, and execution of designs while handling basic tasks.

Benefits

  • Opportunities for mentorship and direct impact on junior developer growth.
  • Engagement in hands-on coding and architecture within a cutting-edge tech stack.
  • Participation in company demo days and customer engagements, showcasing progress.
  • Exposure to cross-team collaborations, integrating diverse functionalities.
  • Potential for working with advanced systems in defense, maritime, and autonomous domains.
Full Job Description
Role Overview

Architecture and Design
  • Own the architecture of assigned TempestOS subsystems end to end: service boundaries, interfaces, data models, failure modes, and upgrade paths.
  • Design for AI Native development. Our team employs AI agents in the design and development of code with our developers providing context and oversight.
  • Produce written design artifacts at a level of detail a developer can implement without escalating for interpretation.
  • Design for the constraints TempestOS operates under: resource-constrained edge hardware, DDIL links, container orchestration without a reachable control plane, and policy enforcement at runtime.
  • Treat security posture as a first-order design input rather than a review gate: least privilege, supply chain attestation, and runtime integrity built into the design rather than bolted on.
  • Make the tradeoffs explicit. Every significant decision carries a written rationale and the alternative that was rejected.
  • Sequence and decompose designs so work can be parallelized across developers of varying experience without creating integration debt.
Design Review and Technical Standards
  • Serve as design authority for changes to subsystems. Review proposals before implementation starts, not after the merge request lands.
  • Enforce and mature standards for testing, interface versioning, documentation, and backward compatibility across TempestOS services. This includes updating AI governance documents.
  • Identify architectural drift early and propose the correction while it is still cheap.
  • Say no to designs that will not survive contact with a deployed system, and explain why in terms the author can act on.
Mentorship and Developer Growth
  • Pair with junior and mid-level developers on problems above their current level, with the goal that the goal for them to handle the next challenge on their own.
  • Review code with intent to teach. Explain the reasoning behind the corrections over providing the fix.
  • Break complex designs into scoped, implementable tasks that stretch a developer without setting them up to fail.
  • Run design walkthroughs and internal technical sessions so architectural context is shared rather than held.
  • Give direct, timely feedback on quality and delivery. Escalate persistent performance concerns to Engineering leadership.
  • Build the bench. The measure is junior developers producing sound designs of their own within a year.
Hands-On Contribution
  • Write production code against the TempestOS codebase.
  • Prototype the risky part of a design and prove it before handing the rest off.
  • Take the unglamorous work when it is the fastest path to unblocking the team.
Cross-Team and Partner Integration
  • Work with the platform, applications, and field engineering teams so designs account for how the product is actually deployed, integrated, and supported.
  • Support integration of partner payloads and capabilities as containerized services on TempestOS, including the interface and policy work that makes those integrations repeatable.
  • Demonstrate progress at company demo days and customer engagements, and occasionally support bid and proposal activity where technical architectural inputs are needed.


Qualifications

Core
  • Eight or more years of professional software engineering experience, including significant time designing systems that other engineers implemented.
  • Demonstrated architecture ownership of a system that shipped and operated under real conditions .
  • Mastery of at least one statically typed systems language (Go, Rust, C, or C++), with the ability to work through advanced programming concepts. Go experience strongly preferred given the TempestOS stack.
  • Deep Linux systems fluency: process model, filesystems, networking, containers, and the debugging tooling that goes with them.
  • Familiar with AI development and coding tools and comfortable with AI Native development.
  • Container and orchestration competence at a design level (Kubernetes, container runtimes, and image supply chain)
  • Distributed systems fundamentals: service decomposition, message passing, consistency and partition behavior, and data serialization (Protocol Buffers, gRPC, or equivalent).
  • Written and verbal communication strong enough that the design document itself is a primary deliverable, and clear enough to hold up in front of developers, management, and customers.
  • Demonstrated mentorship. The candidate can point to engineers who got materially better because of them.
  • US citizenship, required for clearance eligibility and customer site access.
  • Active US Department of War Secret clearance, or the ability to obtain and maintain one over the duration of employment.
Preferred
  • Defense, maritime, naval, or autonomous systems domain experience; delivery of combat management or command and control software especially relevant.
  • Experience with attribute-based access control, zero-trust architecture, policy engines (OPA/Rego), runtime integrity, or supply chain attestation.
  • Experience with edge compute in DDIL environments and cloud-native development practices applied to network-disconnected systems.
  • Familiarity with GitLab, Harbor, AlmaLinux, or comparable components.
  • Fluency with AI-assisted development workflows, and judgment about where they belong in a safety- and security-critical codebase.
  • Master's degree in computer science, electrical engineering, or a related field.
  • Prior Navy, Marine Corps, or Joint service experience, particularly in engineering, cyber, or unmanned systems roles.
Cultural
  • Decisiveness over consensus. Makes the call with incomplete information and documents the reasoning.
  • Honest about reality. Brings problems to the team rather than softening them.
  • Teaching instinct. Gets satisfaction from an engineer's growth, not only from their own commits.
  • Startup stamina. Caliburn is building at the intersection of tactical systems and advanced software. That occasionally means long hours, in-person work, and travel.

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