Job Overview : Performance Engineer (C++, Python, Rust) – W-2 Contract, US-Based
| 💰 Salary | $70–$110 per hour |
| 📍 Location | United States |
| 🏢 Company | Cincinnatus LLC (staffing partner for leading AI lab) |
| 💼 Category | Software Development / Performance Engineering |
| 📋 Contract Type | W-2 Full-time (not freelance) |
| ⏰ Commitment | 40 hours/week – no other engagements |
| 💸 Payment | W-2 employment (payroll, benefits, compliance) |
| 🔧 Tech Stack | C++, Python, Rust |
About the role:
Join a leading AI lab’s cutting-edge GenAI team to be at the core of the AI revolution. We’re seeking talented Performance Engineers with deep expertise in low-level systems optimization — specifically C++, Python, and Rust — to bring hands-on technical excellence and elevate the quality of AI training and inference infrastructure.
This is a W-2 employment position with Cincinnatus LLC, with the opportunity to be placed at a leading AI Lab as part of their extended workforce. This is a 40-hour full-time engagement, with no conflicts/no other engagements.
What you will do:
- Guide research and engineering teams to close knowledge gaps and improve AI model performance in systems-level optimization, compiler engineering, and runtime performance
- Design challenging, domain-relevant tasks across multiple specializations
- Write accurate and well-structured solutions to performance engineering problems
- Evaluate performance engineering tasks and provide clear, written technical feedback
- Develop guidelines and detailed rubrics to assess systems design quality across AI workloads
- Collaborate with other subject matter experts to ensure consistency and accuracy in training data
What you need:
- 2+ years of dedicated professional experience in performance engineering, systems programming, or low-level optimization
- Deep hands-on expertise in at least one of: C++, Python, or Rust – with working familiarity across the others being a strong plus
- Demonstrable track record of measurable performance improvements on production systems (e.g., latency reduction, throughput gains, memory footprint optimization)
- Demonstrable career progression
- Ability to engage reliably for at least 40 hours/week during weekdays
- Strong written communication skills and the ability to explain complex technical decisions clearly
Important notes:
- 🇺🇸 US location required
- 📋 W-2 contract – not freelance or project-based
- ⏰ 40 hours/week – full-time commitment, no other engagements
- 🏢 Employer of record: Cincinnatus LLC (not Mercor)
- 💰 Highest referral bonus yet: $2,000
- 🚀 Leading AI lab – work on cutting-edge GenAI
Why this job is worth your time:
$70-110/hour to apply your systems optimization expertise to the most advanced Large Language Models, with W-2 benefits and the prestige of working with a leading AI lab.