Software Engineer, Full Stack (W-2 Contract, US Remote)
| 💰 Salary | $50 – $65 per hour |
| 📍 Location | United States |
| 🏢 Company | Cincinnatus LLC (staffing partner for leading AI lab) |
| 💼 Category | Software Engineering / AI |
| 🌍 Remote | Yes (US-based remote) |
| 📋 Contract Type | W-2 Full-time (not freelance) |
| ⏰ Commitment | 40 hours/week |
| 💸 Payment | W-2 employment (payroll, benefits, compliance) |
About the role:
Join a leading AI lab’s cutting-edge GenAI team and help build foundational AI models from the ground up. We’re seeking talented Full-Stack Software Engineers with hands-on production experience across modern application stacks to build, integrate, and stress-test real software on top of frontier models before they ship. You’ll work directly with the AI lab’s engineering manager on fast-moving projects and are expected to onboard quickly and contribute working code early.
What you will do:
- Build and ship full-stack applications, services, and internal tools in Python, Java, Rust, C#, C++, or TypeScript that exercise frontier model capabilities
- Integrate pre-release model APIs into working software, including tool interfaces, evaluation harnesses, and telemetry
- Diagnose and document model and integration failure modes, translating observations into clear written feedback for the research team
- Prototype quickly against shifting requirements, delivering working increments with limited up-front specification
- Collaborate with the engineering manager and other engineers to maintain code quality and architecture
What you need:
- 3+ years of dedicated professional experience building and shipping production software at a recognized, top-tier organization
- Production experience in at least one of Python, Java, Rust, C#, or C++, plus working proficiency in a second language
- Hands-on experience across the stack: backend services and APIs, a modern front-end framework (React or equivalent), relational or document databases, and cloud deployment
- Demonstrated ability to onboard onto an unfamiliar codebase and deliver working code quickly
- Strong written communication skills and ability to explain complex technical decisions clearly
- Ability to engage reliably for at least 40 hours/week during weekdays
Preferred (not required):
- Experience with AI/ML workflows or model evaluation
- Prior work on developer tools, infrastructure, or platform engineering
Important notes:
- 🇺🇸 US location required – fully remote within the United States
- 📋 W-2 contract – not freelance or project-based
- ⏰ 40 hours/week – full-time structured role
- 🏢 Employer of record: Cincinnatus LLC
- 🔧 Multiple language stacks – Python, Java, Rust, C#, C++, TypeScript
- 🚀 Fast-paced AI environment – work with pre-release models
Why this job is worth your time:
$50-$65/hour to build full-stack applications that stress-test frontier AI models, with W-2 benefits and direct collaboration with a leading AI lab.