Momchil Hardalov

Momchil Hardalov

Applied Scientist

Amazon AWS AI Labs


I am an Applied Scientist in Natural Langauge Processing (NLP) at Amazon AWS AI Labs. My research interests include question answering, conversational agents, patterns-based few-shot learning, distant supervision, cross-lingual and cross-domain transfer. Before joining Amazon, I was a Research Scientist at Checkstep Research, where I worked on NLP for content moderation using few-shot learning, semi-supervised and multi-source fine-tuning of pre-trained language models. I did my Ph.D. at Sofia University “St. Kliment Ohridski” on dialog and question answering systems.

I have a strong software engineering background along with extensive experience in developing production systems. I previously held a position as a Machine Learning Engineer at ReceiptBank (now Dext) where I built NLP models for automatic field information extraction from unstructured payment documents. I was also a Machine Learning Engineer in an ad-tech company, Adcash OÜ, where I developed distributed and scalable models for ad recommendations. Prior to that, I created and maintained desktop and web applications while in the roles of a full-stack Software Engineer and Team Lead at Acstre.

For more details you can download my CV and see a list of my publications.

  • Natural Language Processing
  • Few-Shot Learning with Large Language Models
  • Semi-Supervised Learning
  • Multilingual Learning
  • Stance Detection
  • Abusive Language Detection
  • Question Answering
  • Conversational Agents
  • Ph.D. Candidate in Natural Language Processing, 2017-2023 (Expected)

    Sofia University "St. Kliment Ohridski", Sofia, Bulgaria

  • MSc in Information Retrieval and Knowledge Discovery, 2014-2016

    Sofia University "St. Kliment Ohridski"

  • BEng in Computer Systems and Technologies, 2010-2014

    Technical University-Sofia

Recent News


Amazon AWS AI Labs
Applied Scientist II
Nov 2022 – Present Barcelona, Spain
Working on information extraction from long-form texts in conversational threads.
Checkstep Research
Research Scientist
Nov 2020 – May 2022 Sofia, Bulgaria

Conducted research in natural language processing for content moderation and stance detection.

  • Published 5 scientific papers, 4 are accepted to appear in top-tier venues.
  • Developed, productionalized and delivered models to end clients in collaboration with the dev team.
  • Curated machine learning models based on the specifics in the clients' policy definitions.
  • Worked on few-shot and multi-domain learning for mono and cross-lingual stance detection.
  • Researched semantic neighborhood models for cross-lingual abusive language detection.
Receipt Bank (now Dext)
Machine Learning Engineer
Oct 2019 – Oct 2020 Sofia, Bulgaria

Worked on automatic field information extraction from unstructured payment documents.

  • Improved the extraction coverage and the overall accuracy of key fields (4%--10% depending on the field and the metric).
  • Developed models for new (client requested) fields working closely with the Business team.
  • Researched, prototyped, and productionalized machine learning models.
Adcash OÜ
Machine Learning Engineer
Aug 2015 – Oct 2017 Sofia, Bulgaria

Developed distributed and scalable product serving ad recommendations.

  • Increased the company's profit by 7% with a new ad serving (exploitation) model.
  • Increased the ad diversity by 12% and the revenue by 5% with a new (exploration) model.
  • Researched, prototyped, and productionalized machine learning models.
  • Designed and executed experiments (A/B tests) for model optimizations.
  • Worked closely with the Business team to design new features.
Team Lead
Jul 2010 – Aug 2015 Sofia, Bulgaria

Designed, developed and maintained desktop and web applications. Led a small team of developers.

  • Productionalized an unified user management and security system integrated into more than 20 company products spanning over 250 organizations.
  • Built an event-based notification system with communication channels as plug-ins.
  • Successfully migrated existing projects' legacy database management system to PostgreSQL.
  • Delivered multiple software projects by leading 3-5 people project teams.
  • Gathered technical specifications for new products/features from clients.