For employers

Hire this AI Trainer

Sign in or create an account to invite AI Trainers to your job.

LoginCreate account
Invite to Job
Leon Bienert

Leon Bienert

AI Training Specialist / Data Annotator

Germany flagHannover, Germany
$16.00/hrIntermediateInternal Proprietary Tooling

Key Skills

Software

Internal/Proprietary Tooling

Top Subject Matter

Computer Vision
Object Detection
Ocr Domain Expertise

Top Data Types

ImageImage
AudioAudio
VideoVideo

Top Task Types

RLHF
Evaluation Rating
Prompt Response Writing SFT
Data Collection
Fine Tuning
Transcription

Freelancer Overview

As an AI Training Specialist with 2+ years of professional experience, I specialize in complex, quality-focused data annotation and research workflows. Backed by a Bachelor of Engineering from Leibniz Universität Hannover (2024), I bring a highly analytical approach to my work and excel at rapidly mastering proprietary internal tools. My expertise spans multiple modalities, including Image, Text, and Audio. I am highly proficient in advanced labeling workflows such as precise image segmentation, Reinforcement Learning from Human Feedback (RLHF), and comprehensive AI model evaluation.

IntermediateEnglishGerman

Labeling Experience

Object Annotation

VideoObject Detection
Responsible for the frame-by-frame annotation and tracking of dynamic objects in video datasets to train computer vision models. The work involved maintaining strict temporal consistency across frames and executing specialized labeling tasks, such as 'Video Color Picker', to accurately classify visual attributes over time. Delivered high-quality ground-truth data essential for improving video recognition and generative AI video models.

Responsible for the frame-by-frame annotation and tracking of dynamic objects in video datasets to train computer vision models. The work involved maintaining strict temporal consistency across frames and executing specialized labeling tasks, such as 'Video Color Picker', to accurately classify visual attributes over time. Delivered high-quality ground-truth data essential for improving video recognition and generative AI video models.

2024 - Present

AI Training Specialist / Data Annotator

Audio
In my audio processing tasks, I collected and recorded German speech data designed to train expressive text-to-speech models. I also performed evaluations on AI-generated speech, comparing outputs to human voice recordings for naturalness and emotional accuracy. My work further extended to reviewing and correcting transcriptions for both English and German audio data. • Recorded quality German voice samples with precisely targeted emotional expression. • Evaluated AI voice outputs for pronunciation, clarity, and realism. • Reviewed and corrected AI-generated transcription for ground-truth alignment. • Supported model fine-tuning through consistent and accurate annotation.

In my audio processing tasks, I collected and recorded German speech data designed to train expressive text-to-speech models. I also performed evaluations on AI-generated speech, comparing outputs to human voice recordings for naturalness and emotional accuracy. My work further extended to reviewing and correcting transcriptions for both English and German audio data. • Recorded quality German voice samples with precisely targeted emotional expression. • Evaluated AI voice outputs for pronunciation, clarity, and realism. • Reviewed and corrected AI-generated transcription for ground-truth alignment. • Supported model fine-tuning through consistent and accurate annotation.

2024 - Present

Conversation Head-to-Head

TextRLHF
I participated in reinforcement learning from human feedback (RLHF) for generative AI model training. My responsibilities included ranking and evaluating head-to-head responses from AI models to single prompts and designing prompts to guide AI output. I assessed conversational AI systems for accuracy, tone, helpfulness, and safety. • Conducted prompt engineering to elicit specific outputs from generative AI. • Carried out extensive comparative evaluations across text-to-image and text-to-speech models. • Authored and rated reverse prompts to describe AI-modified images. • Generated and evaluated AI-created website templates to support coding and web design models.

I participated in reinforcement learning from human feedback (RLHF) for generative AI model training. My responsibilities included ranking and evaluating head-to-head responses from AI models to single prompts and designing prompts to guide AI output. I assessed conversational AI systems for accuracy, tone, helpfulness, and safety. • Conducted prompt engineering to elicit specific outputs from generative AI. • Carried out extensive comparative evaluations across text-to-image and text-to-speech models. • Authored and rated reverse prompts to describe AI-modified images. • Generated and evaluated AI-created website templates to support coding and web design models.

2024 - Present

Image Masking

ImageSegmentation
As an AI Training Specialist and Data Annotator, I performed high-precision masking of objects in complex images to enhance object recognition models. My work involved detailed annotation, including applying bounding boxes and polygons to numerously diverse datasets. I ensured the integrity and accuracy of labeled data for computer vision projects across multiple domains. • Executed pixel-perfect segmentation and masking within intricate images. • Labeled objects and text blocks for OCR data preparation using bounding boxes and polygons. • Utilized video annotation tasks such as Video Color Picker for precise color data tagging. • Applied annotations to both English and German-language image data.

As an AI Training Specialist and Data Annotator, I performed high-precision masking of objects in complex images to enhance object recognition models. My work involved detailed annotation, including applying bounding boxes and polygons to numerously diverse datasets. I ensured the integrity and accuracy of labeled data for computer vision projects across multiple domains. • Executed pixel-perfect segmentation and masking within intricate images. • Labeled objects and text blocks for OCR data preparation using bounding boxes and polygons. • Utilized video annotation tasks such as Video Color Picker for precise color data tagging. • Applied annotations to both English and German-language image data.

2024 - Present

Video color picker

VideoClassification
Responsible for frame-by-frame analysis of video datasets. Executed specialized classification tasks (Video Color Picker) by meticulously tagging and classifying visual attributes and color data across dynamic video frames.

Responsible for frame-by-frame analysis of video datasets. Executed specialized classification tasks (Video Color Picker) by meticulously tagging and classifying visual attributes and color data across dynamic video frames.

2023 - Present

Education

L

Leibniz Universität Hannover

Bachelor of Engineering, Mechanical Engineering

Bachelor of Engineering
2019 - 2024

Work History

L

Leibniz Uni Hannover

IT Support Assistant at Leibniz Universität Hannover

Hannover
2020 - 2023