AI Engineer/ML Engineer - Senior Developers - AI Training - Sheffield, UK

prolificacademicltd; United States; Remote; USD 83,000 - 110,000; Full time

Benefits offered by this job

Fully remote

Flexible hours

Job summary

prolificacademicltd is seeking senior AI/ML engineers for a fully remote, contract-based role. You will contribute to training and evaluating large language models, review model explanations, and provide expert feedback through RLHF-based workflows.

The position emphasizes production-grade ML with Transformers, CNNs, and RNNs, plus prompt engineering and RAG. Flexible hours and rapid onboarding are highlighted, with pay described per task and hour.

Qualifications

• Hands-on experience building, deploying, or fine-tuning ML models.
• Experience with neural networks: Transformers, CNNs, RNNs and optimization.
• Experience with prompt engineering, RAG, or RLHF.
• Ability to audit model logic and detect data contamination.

Responsibilities

• Review AI explanations of architectures, losses, and backpropagation for accuracy.
• Audit ML code/notebooks for efficiency and correctness in training/eval pipelines.
• Provide high-quality human feedback to align models through RLHF.
• Assess how AI handles complex chain-of-thought prompts and pinpoint failures.
• Benchmark model outputs against defined taxonomies and metrics.

Skills

ML model development

Production ML

Transformers

RAG RLHF

Model auditing

Education

PhD in CS/AI/related

MS in ML/AI

Tools

PyTorch

TensorFlow/Keras

Hugging Face Transformers

Amazon SageMaker

Pinecone

Milvus

Weaviate

Job description

Role overview

This is a senior-level contract opportunity for experienced AI and machine learning engineers to contribute to the training and evaluation of large language models. Selected candidates join an expert contributor network and complete paid technical tasks that draw on deep production-grade ML expertise. Work is structured as one-hour focused sessions, with researchers typically paying up to $80 per hour for this specialist input, and an initial 10–15 minute skills assessment gates entry.

Responsibilities

• Review AI-generated explanations of model architectures, loss functions, and backpropagation to confirm technical accuracy
• Audit ML code and notebooks, including training loops, preprocessing scripts, and evaluation pipelines, for efficiency and correctness
• Supply the high-quality human feedback used to align models with intent, safety, and helpfulness through reinforcement learning workflows
• Critically assess how AI systems handle complex chain-of-thought prompts and pinpoint where reasoning breaks down
• Run comparative benchmarking between competing model outputs against defined technical taxonomies and performance metrics

Requirements

• Bachelor's, Master's, or PhD in Computer Science, Artificial Intelligence, Robotics, or a related quantitative discipline with an ML focus
• Hands-on production experience building, deploying, or fine-tuning ML models
• Professional-level command of neural network architectures such as Transformers, CNNs, and RNNs, plus associated optimization techniques
• Practical experience with prompt engineering, retrieval-augmented generation (RAG), or reinforcement learning from human feedback (RLHF)
• Ability to audit complex model logic, spot training-data contamination, and evaluate mathematical proofs behind ML algorithms
• Sharp attention to detail when identifying hallucinations, biased outputs, or logical failures in AI-generated technical content

Nice to have

• Expert proficiency with PyTorch or TensorFlow/Keras
• Advanced Python (NumPy, Pandas, Scikit-learn) and working knowledge of Hugging Face Transformers
• Exposure to AWS SageMaker, Google Cloud Vertex AI, Weights & Biases, or LangChain
• Familiarity with vector databases such as Pinecone, Milvus, or Weaviate for RAG evaluation

Benefits and work setup

• Fully remote with flexible hours and no minimum commitment
• Onboarding typically completed within 15 minutes of passing the assessment
• Hourly rates up to $80, with task descriptions, time estimates, and pay shown before acceptance
• Location: Sheffield, United Kingdom