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

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