Mikołaj Zapalski

AI/ML engineer with product building skills

Gdansk, Poland, CET

MZ

About

AI/ML engineer with five years of experience in tech startups, holding a Master's degree in IT & Econometrics. For the past two years, focused on integrating LLMs into applications, with expertise in RAG, GenAI (stable diffusion, style transfer), search, and recommender systems. Combines a strong statistical background with a keen interest in leveraging data for innovative solutions.

Work Experience

Leya

05/2024 - 02/2025

AI Research Engineer

• Designed and optimized LLM infrastructure to support core features like token management, retries, stream parsing, agent failure handling, and snapshot deployments. Integrated new features into the AI backend with a focus on reliability, scalability, type safety, and clean, maintainable code, driving significant product growth. • Authored research reports to guide data-driven decisions, implementing paragraph-level, hallucination-free citations, infinite-context document representation, advanced embeddings, output validation, and RAG pipelines tailored to legal datasets. Regularly applied SOTA research to enhance product capabilities, rigorously tested through a custom evaluation framework to ensure performance, reliability, and scalability. • Reduced the error rate from 2.5% to 0.02% (100x improvement), significantly improving reliability and user satisfaction. Collaborated with stakeholders in high-pressure 'war room' settings, iterating rapidly on user feedback to secure €500k+ deals.

GoE Wellness

09/2023 - 05/2024

Data Scientist

• Integrated and maintained machine learning models for a holistic wellness mobile app, including a personal LLM assistant, in-app content recommendation system, and semantic search engine. • Designed and deployed efficient ML data pipelines for user activity scoring and content retrieval modules, optimizing app performance. • Leveraged Python expertise (pandas, NumPy, PyTorch, FastAPI) to deploy machine learning models on AWS infrastructure, integrating OpenAI API and wearables API with MongoDB for advanced functionalities and user data management.

Epinote

07/2022 - 09/2023

Product Engineer

• Designed, delivered, and owned numerous internal tech solutions (web scrapers, data pipelines, automation tools) that streamlined workflows and boosted efficiency. • Developed a global contractor payroll system, automating monthly processing for 400 employees ($50k/month), including transfers, invoicing, and P&L reporting. • Successfully implemented a 70% efficiency improvement through automation of contractors' legal paperwork pipeline. • Proposed the exploration of OpenAI API for data augmentation, investigating its potential to increase the size of the client's CRM database by 15%. • Utilized Python, Pandas, Jupyter Notebook, JavaScript, Zapier, and Google Sheets to deliver effective solutions.

Epinote
Part-time

04/2020 - 01/2022

Data Analyst

• Managed hundreds of multimodal datasets (vision, tabular, text, audio), ensuring data quality through robust annotation, cleaning, and validation processes. • Developed and implemented data quality checks to improve data integrity for machine learning projects, while iteratively optimizing the data annotation process, resulting in a 10x improvement in project delivery time. • Transitioned to a combined role encompassing project and operations management, ensuring smooth data pipeline execution and client satisfaction. • Led the annotation team, gathered and implemented client requirements and feedback, resulting in a significant improvement in model performance and accuracy.

International Paper
Part-time

2019 - 2021

IT Service Desk Analyst

• Provided technical support and incident management for IT systems and peripherals, effectively resolving issues and monitoring & responding to alerts. • Prioritized tasks to minimize global infrastructure disruptions and enhance user experience.

Fern Flower
Part-time

2018 - 2021

Co-Founder | Gardening services

• Seasonal activity in the garden and home automation sectors.

Education

AGH University of Krakow

2020 - 2022
Master's Degree | IT & Econometrics

Technical University of Valencia

2022 - 2022
Student Exchange | Machine Learning & Data Science

AGH University of Krakow

2017 - 2020
Bachelor's Degree | IT & Econometrics

Skills

Python
OpenAI & Antrophic APIs
FastAPI
pydanticAI
pandas
numpy
scikit-learn
jupyter
pytorch-transformers
LangChain
AWS
Azure
Docker
git
TypeScript

Projects

regalo

gift ideas generator & planner

pydanticAI
LLMs
TypeScript

style transfer paper

2022 master's thesis that discusses GenAI art just before the generative boom

python
pytorch
tensorflow

polish rap bot

pre-LLM era chatbot for discord and meta's services with rap-style song writing feature

python
asyncio
API

@skyblue.yoga

my attempt to create an Artifical Influencer, PoC built for a podcast episode

SD/Flux
LLMs
LangChain

2048-embd

fundamentals of vector word embeddings meet classic 2048 game

word2vec
BERT
python

recommender sys paper

2020 bachelor's thesis that compares different recommender systems for a movie database

python
surprise
numpy