
Stefan Lazov
Verified Expert in Engineering
Machine Learning Engineer and Developer
Sofia, Bulgaria
Toptal member since December 10, 2021
Stefan is a machine learning engineer with around four years of experience in ML and deep learning. He has worked on various industry and research projects. Currently, Stefan is interested in working with new people and using his talent to develop applications that help people automate tasks. He also has experience in ASP.NET, ASP.NET Core, SQL, PostgreSQL, Mongo DB, Docker, and microservices.
Portfolio
Experience
- Machine Learning - 7 years
- OpenCV - 5 years
- Scikit-learn - 5 years
- Pandas - 5 years
- Natural Language Processing (NLP) - 5 years
- Computer Vision - 5 years
- Generative Pre-trained Transformers (GPT) - 5 years
- Deep Learning - 5 years
Preferred Environment
Visual Studio Code (VS Code), PyTorch, TensorFlow, Python, Scikit-learn, Pandas, OpenCV, Natural Language Toolkit (NLTK), SpaCy, IBM Watson Assistant
The most amazing...
...project I have worked on was AI for dental X-rays, including tooth numbering, third molar detection, and disease detection.
Work Experience
AI Engineer
Mohamed Mehdi El Ouali
- Helped the client architect find a solution to their problem, including AI and non-AI components and hosting.
- Assisted the client in storing their data on databases hosted on the cloud.
- Developed a virtual assistant for the client, building on pure large language models (LLMs) functionality.
AI Product Expert & Developer
Bob Hewitt
- Built a virtual assistant for the company to help clients execute operations faster and be more informed about the processes.
- Developed a front end and hosted the virtual assistant on the cloud.
- Assisted the client in integrating large language models (LLMs) into their pipeline.
AI Consultant
Claimit Software Limited
- Developed a system for text classification that helped the client reduce human effort.
- Built a system for image classification of documents that helped the client reduce human effort.
- Assisted the client in integrating their internal systems with large language models (LLMs).
Machine Learning Engineer
AstroMind, Inc
- Developed an API for hosting deep learning models.
- Implemented logging and log filtering via AWE tools.
- Optimized deep learning models to run faster and save the output to storage.
AI Expert
Opari AG
- Leveraged LLMs to optimize the processes within the company's product.
- Performed data scraping in Python to increase the company's database.
- Wrote Go services to incorporate new functionalities within the company's product.
Senior Python Developer
KBC Global Services
- Developed a whole new chatbot system for business clients.
- Integrated a chatbot with various internal banking systems containing customer data using Python, Rasa, AWS, and PostgreSQL.
- Reviewed the pull requests of more junior team members.
- Defined Python coding standards to be used within the team and mentored junior developers.
- Translated business process diagrams to chatbot dialog flows.
ML Developer
Kinner Digital LLC, DBA Profluence Media
- Developed an app capable of summarising videos both visually and textually.
- Used state-of-the-art technology for text and video summarization.
- Acted as a DevOps hosting the whole app on the cloud, handling protocols, databases, virtual machines, etc, and optimizing the cost that the client pays.
Senior AI Engineer
Curie Vision
- Developed and deployed a system for converting 360 views of objects to 3D models by using AI.
- Communicated the output of my work directly with company management. Managed between one to five company staff members at different periods.
- Worked with the AWS cloud environment to train deep learning models, deploy the system, and store the information in databases and S3 buckets.
Senior NLP Engineer
Ontotext
- Developed and deployed a model for extracting relations between biomedical entities.
- Pre-processed a large number of biomedical documents for training the models.
- Communicated the result to both the internal management and the clients.
Chief Executing Officer
Miracle Star LTD
- Established the company with the idea of working on ML-related projects for various clients. I looked for, approached, and presented the offerings of my company to potential clients and partners.
- Acted as a deep learning engineer for a client in the USA. My job was to design and develop deep learning models for dental X-ray images. I worked on tooth numbering, thing molar detection, and establishing data annotation guidelines.
- Signed and managed contracts and company expenses. Hired an accountant to handle tax-related responsibilities.
Machine Learning Team Lead
Ablera
- Worked on a virtual assistant for automating insurance company's operations. My job included learning and implementing some of the methodologies used for training IBM Watson Assistant. For some period I also led a team of three working on the project.
- Served as a co-owner in this company and aside from my engineering duties I worked on recruitment, delivering product presentations for clients, and handling internal team conflicts.
- Worked on a deep learning-driven system for car damage detection. I led a team of three engineers and my job was not only to lead the team but also to design and partially develop the experiments which we conducted.
Deep Learning Engineer
Centroida
- Researched techniques for generating adversarial samples for 'fooling' computer vision model. I implemented state-of-the-art techniques and indeed crafted adversarial samples.
- Designed and developed a deep learning model for keyword extraction on a project for clustering and topic extraction from newspaper articles.
- Worked on a project for a system that can do Twitter sentiment analysis. My responsibilities included designing and developing the deep learning sentiment analysis model and working on the result visualization dashboard, where we used Kibana.
- Designed a deep learning-driven face detection model on a system for video surveillance.
Back-end Engineer
Centroida
- Worked on the development of a property management system. I was responsible for developing the back end for various product features and exposing those functionalities via an API.
- Developed a course registration system. I directly communicated with the client, and gathered requirements, designed the architecture of the product, defined and assigned tasks for other engineers.
- Worked on a project related to a new cryptocurrency exchange-like platform. I was not involved in the development of the blockchain functionalities but in the development of various modules such as user authentication.
Experience
Is Sparse Attention More Interpretable?
https://arxiv.org/abs/2106.01087Face Detection and Identification from Surveillance Cameras
https://www.youtube.com/watch?v=6LmT9icwgb8Demo:
https://www.youtube.com/watch?v=HPOWDhau_bY
Twitter Sentiment Analysis
https://www.youtube.com/watch?v=WHfdpzqaUI4&t=124sDemo
https://www.youtube.com/watch?v=WHfdpzqaUI4&t=124s
Education
Master's Degree in Computer Science
University of Cambridge - Cambridge, United Kingdom
Bachelor's Degree in Mathematics and Computer Science
American University, Bulgaria - Blagoevgrad, Bulgaria
Skills
Libraries/APIs
PyTorch, Scikit-learn, Pandas, OpenCV, Natural Language Toolkit (NLTK), REST APIs, TensorFlow Deep Learning Library (TFLearn), OpenAI Assistants API, OpenAI API, Hugging Face Transformers, Twilio API, NumPy, TensorFlow, SpaCy, Web API, Node.js, React, Keras, Facebook API, YouTube API, FFmpeg, Rasa NLU, Azure Cognitive Services, DeepSpeech
Tools
ChatGPT, Named-entity Recognition (NER), Amazon SageMaker, GitHub, OpenAI o1, You Only Look Once (YOLO), Open Neural Network Exchange (ONNX), AI Prompts, Azure Machine Learning, Dialogflow, Whisper, GraphRAG, Kibana, Tableau
Languages
Python, CSS, HTML, SQL, JavaScript, R, TypeScript, Python 3, Java, C++, C#
Frameworks
SST, LlamaIndex, Agentic Frameworks, LangGraph, ASP.NET, ASP.NET Core, ARKit
Paradigms
Anomaly Detection, ETL, Agile, Automation, Test-driven Development (TDD), DevOps, Microservices
Platforms
Amazon Web Services (AWS), Docker, AWS Security Token Service (STS), HubSpot, Visual Studio Code (VS Code), Azure, Databricks, Azure AI Studio, iOS, Google Cloud Platform (GCP), AWS IoT, Kubernetes, Cloud Run
Storage
MySQL, Data Pipelines, Graph Databases, PostgreSQL, Databases, MongoDB, Amazon S3 (AWS S3), Google Cloud, Elasticsearch
Other
Natural Language Processing (NLP), Machine Learning, Natural Language Generation (NLG), Sentiment Analysis, Deep Learning, Research, Calculus, Linear Algebra, Computer Vision, Artificial Intelligence (AI), Computer Vision Algorithms, AI Design, Video Processing, Object Detection, Chatbots, Chatbot Conversation Design, Machine Learning Operations (MLOps), Datasets, APIs, Large Language Models (LLMs), Image Processing, AI Programming, Early-stage Startups, Image Generation, Full-stack Development, Generative Pre-trained Transformers (GPT), Convolutional Neural Networks (CNNs), Image Recognition, Support Vector Machines (SVM), Frameworks, Data Science, Back-end, Data Analytics, Analytics, Data Manipulation, Statistical Analysis, Data Analysis, Generative Artificial Intelligence (GenAI), Language Models, Prompt Engineering, OpenAI GPT-3 API, Data Versioning, Web Scraping, Recommendation Systems, Software Development, Forecasting, Image Analysis, Big Data, Data Scraping, Time Series, Data Modeling, Predictive Analytics, Regression Modeling, Data Annotation, BERT, Text Analytics, Minimum Viable Product (MVP), FastAPI, Artificial Neural Networks (ANN), Biomedical Products, Machine Learning Algorithms, Open-source LLMs, Open Source, Retrieval-augmented Generation (RAG), Supervised Learning, Optical Character Recognition (OCR), AI Chatbots, AI Agents, Mathematics, Statistics, Multimodal Models, Generative Adversarial Networks (GANs), Text-to-Speech (TTS), Document Processing, Hugging Face, Back-end Development, Generative Pre-trained Transformer 4 (GPT-4), Distributed Training, Transformers, Transformer Models, ChatGPT API, Algorithms, Credit Cards, SDKs, eCommerce, API Integration, Medical Imaging, Data Classification, Vector Databases, Conversational AI, Product Owner, User Journeys, Hexagonal Architecture, Object Tracking, Kalman Filtering, Audio Streaming, Low Latency, Pattern Recognition, Predictive Modeling, Agentic AI, OpenAI SDK, Biology, AI Data Classification, ChatGPT Prompts, Healthcare Data Science, Real World Data, Roboflow, Image Segmentation, Detectron2, CTO, IBM Watson Assistant, Analysis, Linguistics, Abstract Algebra, Facial Recognition, Signal Processing, Generative Models, Generative Pre-trained Transformer 3 (GPT-3), OpenAI GPT-4 API, OpenAI, Pgvector, Pricing, Marketing Mix Modeling, Advertising Technology (Adtech), Voice Analysis, Speech Analytics, Electronic Health Records (EHR), Clinical Trials, Graph Neural Networks (GNNs), Multi-agent Systems, Collaborative AI, LangChain, Large Language Model Operations (LLMOps), Genomics, Gemini, 3D Graphics, Electronic Medical Records (EMR), Biostatistics, Epidemiology, Smart Cities, Smart City Technology, Natural Language Understanding (NLU), Team Leadership, Transportation & Logistics, Speech-to-Text (STT), Speech Recognition, Data Loading, Variational Autoencoders (VAEs), Deep Neural Networks (DNNs), Scraping, Full-stack, Digitization, TikTok, Neuro-symbolic AI, No-code Development, PG Vector, ElevenLabs Solutions, Game Development
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