Matej Kloska, Developer in Bratislava, Bratislava Region, Slovakia
Matej is available for hire
Hire Matej

Matej Kloska

Verified Expert  in Engineering

Machine Learning Developer

Bratislava, Bratislava Region, Slovakia

Toptal member since July 8, 2016

Bio

Matej has more than 10 years of back-end applications development experience. He received his PhD in the field of informatics with a focus on time series and anomaly detection. He is passionate about reusable, testable, clean code and has experience in microservice-oriented clean architecture and container-oriented infrastructure with a focus on Kubernetes. He has wide hands-on experience as a developer, data engineer, and later as CTO. Matej loves back-end and machine-learning challenges.

Portfolio

Kempelen Institute of Intelligent Technologies
Python, NumPy, Pandas, Jupyter, Time Series, Anomaly Detection...
Freelance Clients
Python, Django, Flask, Celery, RabbitMQ, Amazon Simple Queue Service (SQS)...
Faculty of Informatics and Information Technologies
Machine Learning, Big Data, R, Python, NumPy, Data Science...

Experience

  • Python - 7 years
  • Django - 6 years
  • Go - 5 years
  • Microservices Architecture - 5 years
  • Machine Learning - 5 years
  • Time Series - 5 years
  • PostgreSQL - 4 years
  • Kubernetes - 2 years

Availability

Part-time

Preferred Environment

Docker, Git, Vim Text Editor, Visual Studio Code (VS Code), MacOS, Kubernetes

The most amazing...

...things I've coded are a custom RTB platform with a fully customizable personalization ad server and my PhD thesis in the field of time series anomaly detection.

Work Experience

Research Engineer

2021 - PRESENT
Kempelen Institute of Intelligent Technologies
  • Applied various methods for intelligent time series analysis.
  • Developed an application for anomaly detection in power consumption time series.
  • Published a research paper related to anomaly detection.
Technologies: Python, NumPy, Pandas, Jupyter, Time Series, Anomaly Detection, Time Series Analysis, Research, Containerization, Machine Learning, PyTorch, Machine Learning Operations (MLOps), Predictive Modeling, Trend Analysis, CI/CD Pipelines, DevOps, Continuous Integration (CI), Continuous Delivery (CD), Data Analysis, Unit Testing, Testing, Git, Automated Testing, Back-end, Large Language Models (LLMs), Natural Language Processing (NLP), Scikit-learn, Object-oriented Programming (OOP), OpenAI GPT-3 API, Data Analytics, Jupyter Notebook

Senior Engineer

2019 - PRESENT
Freelance Clients
  • Faced challenging tasks related to performance and scaling issues.
  • Acted as the leader of the back-end team. Managed both the technical aspects and team dynamics. Involved in balancing immediate challenges with long-term goals for efficient and sustained growth.
  • Focused on building up DevOps principles and automation, aiming to seamlessly integrate development and operations.
Technologies: Python, Django, Flask, Celery, RabbitMQ, Amazon Simple Queue Service (SQS), Amazon EKS, ECS, Amazon RDS, PostgreSQL, HTML Templates, Containerization, FastAPI, SQLAlchemy, Amazon Web Services (AWS), Django REST Framework, REST, CI/CD Pipelines, DevOps, Continuous Integration (CI), Continuous Delivery (CD), Unit Testing, Pytest, Testing, OpenAI, Git, GitHub, Automated Testing, Back-end, Technical Leadership, APIs, Back-end Architecture, gRPC, Grafana, Orchestration, Cloud Deployment, Object-oriented Programming (OOP), OpenAI GPT-3 API, Back-end Development, Jupyter Notebook

Researcher

2019 - 2020
Faculty of Informatics and Information Technologies
  • Researched anomaly detection methods and techniques in data streams.
  • Pre-processed a large (hundreds of gigabytes) dataset about household energy consumption for further experiments.
  • Assisted in data structures and algorithms courses. Taught two courses, each with 15 students.
Technologies: Machine Learning, Big Data, R, Python, NumPy, Data Science, Time Series Analysis, Artificial Intelligence (AI), Data Analysis, Scikit-learn, Data Analytics, Jupyter Notebook, Research, Jupyter

CTO

2017 - 2019
Alvolia
  • Designed microservices architecture capable of handling 2+ million requests per second (RPS).
  • Implemented novel bidding algorithms for effective real-time bidding with emphasis on correct budget spending.
  • Designed a data pipeline responsible for processing large amounts of data for intelligent cookie segmentation and targeting.
  • Handled the integration process with SSP partners.
Technologies: DSP, Real-time Bidding (RTB), Cassandra, Google Cloud Storage, PostgreSQL, Jira, BigQuery, Google Cloud Platform (GCP), Kubernetes, Apache Kafka, Go, Object-oriented Design (OOD), Data Engineering, Architecture, SQL, Django REST Framework, REST, CI/CD Pipelines, DevOps, Continuous Integration (CI), Unit Testing, Automated Testing, Back-end, Technical Leadership, APIs, Back-end Architecture, gRPC, Google Cloud Build, Gin-Gonic, Grafana, Orchestration, Cloud Deployment, Object-oriented Programming (OOP), CTO, Back-end Development

CTO

2011 - 2018
AdBOOST
  • Created a scalable synchronization pipeline for millions of ads and search keywords in real-time.
  • Worked as a full-stack developer with a primary focus on the back end.
  • Designed a Kubernetes-based microservice-oriented architecture.
  • Worked on business goals and communication with customers.
  • Realized migration from on-prem infrastructure to Google Cloud Platform.
Technologies: Google Ads API, Google Analytics API, PostgreSQL, Jira, Celery, Aerospike, Kubernetes, RabbitMQ, Redis, Django, Python, Object-oriented Design (OOD), Data Engineering, Architecture, SQL, Django REST Framework, REST, CI/CD Pipelines, DevOps, Continuous Integration (CI), Unit Testing, Automated Testing, Technical Leadership, APIs, Back-end Architecture, Java, Google Cloud Build, Grafana, Cloud Deployment, Object-oriented Programming (OOP), CTO, Back-end Development

Teaching Assistant

2016 - 2017
Faculty of Informatics and Information Technologies
  • Assisted parallel programming and database systems courses.
  • Provided hands-on coding sessions for groups of students at the university.
  • Managed assignments for course students performing corrections and evaluations.
  • Regularly mentored students and their term projects.
Technologies: Databases, SQL, NoSQL, Time Series Analysis, Java, Object-oriented Programming (OOP), Jupyter

Researcher

2015 - 2016
Faculty of Informatics and Information Technologies
  • Supported the faculty content and metadata system COME2T.
  • Implemented multiple methods of keyword extraction from a corpus of documents.
  • Built a UX-friendly tool for easy comparison of similar XML files.
Technologies: Anomaly Detection, Redmine, JavaScript, Ruby on Rails (RoR), Ruby, Python, NumPy, Data Science, Time Series Analysis, Data Engineering, Data Analysis, Data Analytics, Research, Jupyter

Freelance Developer

2010 - 2015
Contractor
  • Created a custom Python-based CMS for the clients.
  • Handled basic HTML/CSS work for various clients such as small websites and newsletters.
  • Maintained multiple small websites for various clients from the eCommerce and public sectors.
Technologies: PostgreSQL, MySQL, JavaScript, Django, Python, Unit Testing

AdBOOST

Intelligent multi-network marketing platform for advertising agencies and individuals. AdBOOST helps automatically advertise your eCommerce products properly at scale (millions of keywords and ads in real time).

Alvolia

Alvolia helps advertisers in real-time bidding campaigns as SaaS DSP. I made all the decisions regarding technology selection, architecture design and development, and critical modules of the system. The whole system was designed from the ground up and distributed as a fault-tolerant system operating at high RPS rates (2+ million RPS).

COME2T

A system that allows easy administration of lightweight semantics for the provided content and user-created annotations, which are often created as a result of implicit collaboration between users of a web-based application.

Asgardlogy

https://ieeexplore.ieee.org/abstract/document/7753377
In this work, I tackled supporting efficient concept map authoring for capturing document semantics by proposing and evaluating enhancements in a graph-based user interface of our document management tool. The presented enhancements constitute the first stage of my research on facilitating document semantics authoring.

Achieved results were published in the 11th International Workshop on Semantic and Social Media Adaptation and Personalization (SMAP).
2017 - 2023

PhD in Informatics

Technical University of Košice - Košice, Slovakia

2014 - 2016

Master's Degree in Information Systems

Slovak University of Technology at Bratislava - Bratislava, Slovakia

2011 - 2014

Bachelor's Degree in Informatics

Slovak University of Technology at Bratislava - Bratislava, Slovakia

MAY 2018 - PRESENT

Executive Data Science

Johns Hopkins University | via Coursera

MAY 2018 - PRESENT

Machine Learning

Stanford University | via Coursera

Libraries/APIs

Google Ads API, Google Analytics API, REST APIs, SQLAlchemy, Scikit-learn, TensorFlow, Facebook Marketing API, Facebook Ads API, Bing API, NumPy, PySpark, Pandas, PyTorch

Tools

Google Kubernetes Engine (GKE), Git, BigQuery, Celery, RabbitMQ, Grafana, Pytest, Vim Text Editor, Jira, Redmine, Google Analytics, Jupyter, Amazon Simple Queue Service (SQS), Amazon EKS, GitHub

Languages

SQL, Go, Python, C, Ruby, R, PHP, JavaScript, Java

Frameworks

Django, gRPC, Flask, Gin-Gonic, Django REST Framework, Ruby on Rails (RoR), AngularJS

Paradigms

Unit Testing, Back-end Architecture, Test-driven Development (TDD), Object-oriented Design (OOD), Behavior-driven Development (BDD), Microservices, Anomaly Detection, Microservices Architecture, REST, DevOps, Continuous Integration (CI), Continuous Delivery (CD), Testing, Object-oriented Programming (OOP), Agile Software Development, Automated Testing

Storage

PostgreSQL, Aerospike, MongoDB, Redis, MySQL, Google Cloud Storage, Google Cloud, ScyllaDB, NoSQL, Databases, Cassandra, Elasticsearch, Cloud Deployment

Platforms

Docker, Kubernetes, Apache Kafka, Amazon Web Services (AWS), MacOS, Google Cloud Platform (GCP), Zendesk, Google Ads, Visual Studio Code (VS Code), Jupyter Notebook

Other

Machine Learning, Real-time Bidding (RTB), Data Science, Time Series, Artificial Intelligence (AI), CI/CD Pipelines, Back-end, Back-end Development, Distributed Systems, DSP, Google Cloud Build, Data Engineering, Data Build Tool (dbt), Architecture, Forecasting, Containerization, FastAPI, Machine Learning Operations (MLOps), Predictive Modeling, Trend Analysis, Data Analysis, Technical Leadership, APIs, Orchestration, Data Analytics, SOC 2, Big Data, Analytics, DMP, Prometheus, Information Systems, Informatics, Time Series Analysis, Research, ECS, Amazon RDS, HTML Templates, OpenAI, Large Language Models (LLMs), Natural Language Processing (NLP), CTO, OpenAI GPT-3 API

Collaboration That Works

How to Work with Toptal

Toptal matches you directly with global industry experts from our network in hours—not weeks or months.

1

Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.
2

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.
3

Start your risk-free talent trial

Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.

Top talent is in high demand.

Start hiring