Software Engineer - Software Defined Networking (SDN)
Posted Oct 1, 2026
The role in short
Embed with the Navy FDE team to assess, harden, and modernize a government-provided SDN codebase, delivering secure and maintainable software baselines.
Role Description:
Defense Unicorns is seeking a Software Engineer to own the assessment, hardening, testing, and modernization of a Government-provided software-defined networking (SDN) baseline capability. You will join the Defense Unicorns Navy Forward Deployed Engineering (FDE) team and be responsible for understanding an unfamiliar codebase, improving its security and maintainability, and delivering a reliable software baseline that can be sustained as mission requirements evolve.
This is a software-engineering role with a systems and networking focus. You will work directly with source code, build systems, dependencies, runtime behavior, test suites, and open-source integrations. You will diagnose complex issues across application and network boundaries, remediate vulnerabilities, and leverage AI tools to maintain and develop applications within DevSecOps pipelines. Additionally, you will establish disciplined engineering practices around code quality, release readiness, and long-term sustainment.
Working with Defense Unicorns platform engineers and Government stakeholders, you will integrate the SDN application codebase to ensure the software can be built, tested, packaged, deployed, and operated successfully for Navy environments.
Responsibilities:
The listed responsibilities are not exhaustive and additional responsibilities may be assigned based on the evolving needs of the organization. We are seeking a dynamic individual who is able to adapt and take on new responsibilities as they arise.
- Own the technical assessment of an SDN codebase, including architecture, build process, dependency evaluation and management, runtime components, test coverage, security posture, and upstream open source relationships.
- Design and implement secure, maintainable changes that remediate vulnerabilities, improve resilience, and preserve traceability between upstream software, Government-owned code, configurations, and local patches.
- Develop trustworthy unit, integration, end-to-end, regression, and failure-mode tests for hardening and modernization changes.
- Institute AI-enabled tooling to enable the hardening and maintenance of the SDN application codebase.
- Debug complex behavior across application, Linux, and network boundaries, including traffic flows, routing, segmentation, identity, failover, telemetry, and performance.
- Partner with platform engineers on container readiness, packaging, CI/CD, deployment workflows, and automated security scanning while owning code-level triage and remediation.
- Support lab validation, demonstrations, release acceptance, and conversion of operational findings into durable fixes and regression tests.
- Produce clear technical documentation, participate in architecture and code reviews, communicate tradeoffs to stakeholders, and mentor other engineers.
Basic Experience and Qualifications
- 5+ years of software-engineering experience, proficiency in C++, Python and Bash scripting, and demonstrated ownership of production or legacy codebases.
- Strong Linux fundamentals, including services, processes, permissions, logging, package management, and command-line troubleshooting.
- Strong networking fundamentals, including TCP/IP, routing, DNS, TLS, segmentation, interfaces, policy enforcement, and traffic analysis.
- Experience with secure software development, dependency management, vulnerability triage, patching, code review, and remediation.
- Strong testing discipline across unit, integration, end-to-end, and regression testing.
- Working knowledge of containers, version control, build automation, CI/CD, registries, observability, and modern release practices.
- Strong problem-solving, communication, and documentation skills, including design documents, technical assessments, and runbooks.
- U.S. citizenship and ACTIVE US Government SECRET security clearance or higher.
Preferred Experience and Qualifications:
- Experience developing or sustaining SDN, network orchestration, routing, virtual network functions, network appliances, or other network-control software.
- Experience containerizing VM-based or monolithic software and maintaining upstream open source integrations, forks, or patches.
- Strong familiarity with agentic AI-assisted engineering tools and workflows for maintaining and developing software products, accelerating codebase analysis and remediation, and supporting automated resilience, failure-mode, and chaos testing.
- Familiarity with Kubernetes, Helm, GitOps, OCI artifacts, and/or software delivery.
- Experience with SAST, DAST, software composition analysis, SBOMs, container scanning, STIGs, and automated security checks.
- Experience with performance, resilience, or chaos engineering and observability for distributed or networked systems.
- Experience modernizing and migrating applications from virtual machine-based environments to containerized deployments.
Prep for this interview
4 questions likely to come up at Defense Unicorns, each matched to a line in this posting.
- 1Cloud, deployment and security
They wrote: “U.S. citizenship and ACTIVE US Government SECRET security clearance or higher.”
The customer's security team sends a 200-question review. How do you handle it?
How to answer
Why they ask: Security reviews often block deals. FDEs help get through them.
- Start from your company's standard answers (SOC 2 report, past reviews)
- Answer clearly; don't oversell
- Bring in your security team for anything you're unsure of
- Keep the new answers for the next customer
Tip: Reuse past answers, flag honest gaps, and offer a call for the hard questions.
- 2Discovery and scoping
They wrote: “Produce clear technical documentation, participate in architecture and code reviews, communicate tradeoffs to stakeholders, and mentor other engineers.”
A customer says “we want AI in our claims process.” What do you ask in the first meeting?
How to answer
Why they ask: Most FDE work starts this vague. They want to hear you find the real problem before you pick a tool.
- Map the current process: who touches a claim, in what order, with which systems
- Find the slowest or most error-prone step and ask what it costs them
- Agree on one measurable goal (for example time per claim, or error rate)
- Ask what data you can access, and who signs off on security
Tip: Ask about the work, not the technology. Who does it today, how long it takes, what a mistake costs, and how they'd know it got better.
- 3Integrations and APIs
They wrote: “Develop trustworthy unit, integration, end-to-end, regression, and failure-mode tests for hardening and modernization changes.”
Walk me through connecting our product to a customer's internal system that has no documentation.
How to answer
Why they ask: This happens weekly in the job. They want a calm, step-by-step method.
- Find who owns the system and get read access to a test environment
- Watch real traffic or logs to learn the data shapes
- Build a thin adapter with logging around every call
- Agree on how failures get reported, and who fixes what
Tip: Talk about finding the owner of the system first. The code is the easy part.
- 4Coding
They wrote: “5+ years of software-engineering experience, proficiency in C++, Python and Bash scripting, and demonstrated ownership of production or legacy codebases.”
Here's a CSV export from a customer. Write a script that cleans it and loads it into our API.
How to answer
Why they ask: Very close to real FDE work. They watch how you handle bad rows and failures.
- Read with a proper CSV parser; check the header first
- Validate each row and collect errors, not crash on the first one
- Send in batches with retries and a clear report at the end
- Write one or two quick tests for the parsing
Tip: Talk through edge cases out loud: encodings, missing fields, duplicates, rate limits.
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