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David Maina

David Maina

AI Data Annotator | LLM Training, Fraud Detection & Healthcare Data-I data annotator with experience in LLM training, prompt engineering, and RLHF. Skilled in evaluating and improving AI outputs for accuracy, safety, and quality. Experienced in fraud detection and anomaly detection using machine learning, including real-time transaction analysis. Strong background in Python, NLP, and data annotation across healthcare and financial datasets.

United Kingdom flagFolkestone, United Kingdom
$35.00/hrExpertData Annotation TechV7 LabsTelus

Key Skills

Software

Data Annotation TechData Annotation Tech
V7 LabsV7 Labs
TelusTelus
TolokaToloka
Scale AIScale AI
RemotasksRemotasks
Redbrick AIRedbrick AI
AppenAppen
ClickworkerClickworker
LabelboxLabelbox
MercorMercor
Micro1

Top Subject Matter

Healthcare – Medical Records & Patient Data Annotation
Finance – Fraud Detection & Risk Analysis
Technology – LLM Training & NLP Annotation

Top Data Types

Computer Code ProgrammingComputer Code Programming
TextText
ImageImage

Top Task Types

Bounding Box
Polygon
Prompt Response Writing SFT
Data Collection
Computer Programming Coding
RLHF
Evaluation Rating
Question Answering
Classification
Function Calling
Fine Tuning
Object Detection

Freelancer Overview

2024 Dec-2025 May AI Trainer Outlier AI / Freelance, Remote • Created and refined high-quality prompts and responses used to train and evaluate large language models (LLMs) across diverse domains including technology, science, and general knowledge. • Evaluated and ranked AI-generated responses based on factual accuracy, coherence, tone, safety, and adherence to project guidelines. • Performed detailed feedback and annotation tasks to improve model outputs using Reinforcement Learning from Human Feedback (RLHF). • Conducted fact-checking and research to ensure responses were accurate, reliable, and aligned with verified information sources. • Identified model weaknesses, hallucinations, biases, and logical inconsistencies by acting as an adversarial user during testing tasks. • Applied complex annotation guidelines and evaluation frameworks to maintain high-quality AI training datasets. • Contributed to improving AI performance in coding, reasoning, writing, and conversational tasks.

ExpertEnglish

Labeling Experience

No Data Labeling experience added

David M. hasn’t added any AI Training or Data Labeling experience to their OpenTrain profile yet.

Education

C

Canterbury Christ Church University

Msc in Cyber security , Cyber security Technology

Msc in Cyber security
2024 - 2026
M

Moringa School

Computer science , Information Technology

Computer science
2022 - 2023

Work History

M

Mercor

AI training

Folkestone
2025 - 2026
C

Canterbury Christ Church University

Researcher Apprenticeship

Canterbury
2025 - 2025