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Principal Engineer, AI Model LifeCycle

Crusoe

Crusoe

Software Engineering, Data Science
San Francisco, CA, USA
Posted on Feb 6, 2026

Location

San Francisco, CA - US

Employment Type

Full time

Location Type

On-site

Department

Cloud Engineering

Crusoe's mission is to accelerate the abundance of energy and intelligence. We’re crafting the engine that powers a world where people can create ambitiously with AI — without sacrificing scale, speed, or sustainability.

Be a part of the AI revolution with sustainable technology at Crusoe. Here, you'll drive meaningful innovation, make a tangible impact, and join a team that’s setting the pace for responsible, transformative cloud infrastructure.

About the Role:

The Principal Software Engineer for the Model LifeCycle team will play a crucial role in building a comprehensive managed platform for the entire application development lifecycle, with a specific focus on leveraging Machine Learning models, including Large Language Models (LLMs).

What You will be working on:

  • Manage fine-tuning systems for large foundation models (SFT, PEFT, LoRA, adapters), including multi-node orchestration, checkpointing, failure recovery, and cost-efficient scaling.

  • Implement and maintain end-to-end training pipelines for Large Language Models.

  • Distillation and reinforcement learning pipelines (e.g., preference optimization, policy optimization, reward modeling).

  • Agent execution infrastructure

  • Dataset, model, and experiment management: versioning, lineage, evaluation, and reproducible fine-tuning at scale.

Collaboration and impact

  • Work closely with product, business, and platform teams to shape the core abstractions and APIs of the system.

  • Influence long-term architectural decisions around training runtimes, scheduling, storage, and model lifecycle management.

  • Contribute to and engage with the open-source LLM ecosystem.

  • This role offers significant 0 → 1 ownership — you'll be designing and building core systems from first principles.

What You’ll Bring to the Team:

  • Strong Engineering Fundamentals:

    • Advanced degree in Computer Science, Engineering, or a related field.

    • 10-15+ years of industry experience driving impactful projects in the AI Space

    • Proven track record of delivering early-stage projects under tight deadlines.

    • Expertise in using cloud-based services, such as, elastic compute, object storage, virtual private networks, managed database, etc.

  • AI/ML Expertise:

    • Experience in Generative AI (Large Language Models, Multimodal).

    • Deep experience with AI infrastructure, including training, inference.

Bonus Points:

  • Proficiency in Golang or Python for large-scale, production-level services.

  • Contributions to open-source AI projects such as vLLM or similar frameworks.

  • Performance optimizations on GPU systems and inference frameworks.

  • Experience working with PyTorch

  • Experience with training and fine-tuning LLMs

  • Personal Attributes:

    • Proactive and collaborative approach with the ability to work autonomously.

    • Strong communication and interpersonal skills.

    • Passion for building cutting-edge AI products and solving challenging technical problems.

Benefits:

  • Industry competitive pay

  • Restricted Stock Units in a fast growing, well-funded technology company

  • Health insurance package options that include HDHP and PPO, vision, and dental for you and your dependents

  • Employer contributions to HSA accounts

  • Paid Parental Leave

  • Paid life insurance, short-term and long-term disability

  • Teladoc

  • 401(k) with a 100% match up to 4% of salary

  • Generous paid time off and holiday schedule

  • Cell phone reimbursement

  • Tuition reimbursement

  • Subscription to the Calm app

  • MetLife Legal

  • Company paid commuter benefit; $300/month

Compensation Range

Compensation will be paid in the range of up to $256,000 - $320,000 + Bonus. Restricted Stock Units are included in all offers. Compensation to be determined by the applicants knowledge, education, and abilities, as well as internal equity and alignment with market data.

Crusoe is an Equal Opportunity Employer. Employment decisions are made without regard to race, color, religion, disability, genetic information, pregnancy, citizenship, marital status, sex/gender, sexual preference/ orientation, gender identity, age, veteran status, national origin, or any other status protected by law or regulation.