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David Mwangi

David Mwangi

5+ yrs experience in data labeling/ data annotation for AI, CV & NLP models

Kenya flagNairobi, Kenya
$20.00/hrExpertAppenClickworkerDataturk

Key Skills

Software

AppenAppen
ClickworkerClickworker
DataturkDataturk
MindriftMindrift
OneFormaOneForma
RemotasksRemotasks
Snorkel AISnorkel AI
TolokaToloka
TelusTelus
Scale AIScale AI

Top Subject Matter

No subject matter listed

Top Data Types

Geospatial Tiled ImageryGeospatial Tiled Imagery
TextText
VideoVideo

Top Task Types

Classification
Diagnosis
Evaluation Rating
Prompt Response Writing SFT
RLHF

Freelancer Overview

With a strong foundation in mathematics and a deep commitment to detail, I bring hands-on experience in AI training data projects across multiple domains. I have contributed to data labeling and annotation tasks for leading platforms such as Mindrift, Telus AI, OneForma, and Toloka. My work spans e-commerce product image and text labeling, where I helped structure large-scale datasets to improve product search and categorization; social media content annotation, supporting safety and moderation algorithms; and English LLM evaluation, where I reviewed AI-generated outputs for factual accuracy, coherence, and ethical alignment. What sets me apart is my ability to combine analytical thinking with linguistic precision. My academic background at the PhD level honed my attention to logic and structure, which I now apply to complex annotation tasks. Whether evaluating the tone of a chatbot response or tagging object boundaries in images, I approach every task with care, consistency, and a deep understanding of how high-quality data shapes smarter AI. I’m equally comfortable following strict guidelines and providing insightful feedback that helps refine annotation protocols.

ExpertEnglishSpanishJapanese

Labeling Experience

Clickworker

E-commerce Image & Text Labeling for Product Categorization

ClickworkerImageBounding BoxClassification
In this project, I annotated and labeled thousands of e-commerce product images and titles to improve machine learning models used for product recommendation, visual search, and categorization. My tasks included drawing bounding boxes around key visual features (e.g., logos, packaging), assigning accurate product categories and attributes, and verifying text metadata like titles and specifications. The project involved high-volume labeling with strict accuracy standards (>95%), reviewed through multiple QA rounds. I ensured compliance with dynamic guidelines, maintained label consistency, and met tight deadlines while delivering high-quality work that directly contributed to AI training for global retail clients.

In this project, I annotated and labeled thousands of e-commerce product images and titles to improve machine learning models used for product recommendation, visual search, and categorization. My tasks included drawing bounding boxes around key visual features (e.g., logos, packaging), assigning accurate product categories and attributes, and verifying text metadata like titles and specifications. The project involved high-volume labeling with strict accuracy standards (>95%), reviewed through multiple QA rounds. I ensured compliance with dynamic guidelines, maintained label consistency, and met tight deadlines while delivering high-quality work that directly contributed to AI training for global retail clients.

2021 - 2024

Education

U

University of Nairobi

PhD in Mathematics, Mathematics

PhD in Mathematics
2018 - 2024
E

Egerton University

Master of Arts in Mathematics, Mathematics

Master of Arts in Mathematics
2017 - 2018

Work History

S

St. Paul University

Instructor of Record

Nairobi
2022 - Present
S

St. Paul University

Head Teaching Assistant

Nairobi
2018 - 2022