Marcin Kosztołowicz, Developer in Kraków, Poland
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Marcin Kosztołowicz

Verified Expert  in Engineering

Software Developer

Kraków, Poland
Toptal Member Since
August 22, 2015

A year ago, Marcin earned the master's degree in computer science and currently is a student of philosophy. During his studies, he worked as an Android developer for 2 years. Then, he participated in projects related to data analysis. Recently, he has been associated with a cognitive science laboratory. His passion for solving problems demonstrates his intense focus and desire to learn and use new technologies.


Momo (via Toptal)
REST, Java, Android
Python, JavaFX, R, Octave, Spring, Java
PostgreSQL, ORMLite, SQLite, Java, Android




Preferred Environment

Android Studio, Git, PyCharm, Linux, GNU

The most amazing...

...feature I've created was a voice recognition algorithm for intelligent building software.

Work Experience

Android Developer

2015 - 2016
Momo (via Toptal)
  • Mirrored an iOS social app and implemented new features.
  • Implemented Android application WhatNow.
  • Designed Android application architecture.
Technologies: REST, Java, Android

Software Developer

2014 - 2015
  • Created a voice command recognition plugin. The algorithm was based on MFCC and implemented in Java (Spring). Research and prototyping was made in R and Octave.
  • Developed a JavaFX application focused on UX experience.
  • Did preliminary research of data coming from LeapMotion.
  • Created a Java implementation of an ARMA forecasting algorithm.
  • Conducted research, reading scientific papers and prototyping algorithms.
Technologies: Python, JavaFX, R, Octave, Spring, Java

Android Developer

2012 - 2014
  • Designed and implemented Android applications. Used a REST API and SQLite (ORMLite) for on-device storage.
  • Conducted server-side administration, installing and running Java web applications (Apache, PostgreSQL).
  • Created customized UI components.
  • Researched a video chat feature, using ooVoo (WebRTC).
  • Implemented unit tests and instrumentation tests.
  • Participated in Scrum meetings.
Technologies: PostgreSQL, ORMLite, SQLite, Java, Android

Carpyen (LAMP Catalog)

An Android application which was a base for building catalog-like applications. Content was provided by server (REST API), and it had an offline mode and synchronization feature.

Build examples: Carpyen, Studenckie Zniżki Kraków

Torba Kangura (Points of Interest for Parents)

Mobile application (Android) which provides useful information for parents with kids. It is possible to find interesting places where a parent can take their child. Data is provided for major cities in Poland.

Ancilla (Care Assistance)
A system which was supposed to help in taking care of old people. There were two separate mobile applications, one for the elderly patient and one for the caregiver. UI design by Przemyslaw Brzezinski.

Voice Command Recognition Plugin

Voice command recognition used in intelligent building systems. Based on MFCC. Prototyped in Octave and R, implemented in Java.

Cavern Laboratory

JavaFX application designed to simplify computation of land surface changes caused by cavern exploitation.

Cryptocurrency Trade and Mining System

System based on Cron and Python code which was adjusting cryptocurrency mining to cryptocurrency market circumstances combined with auto-selling.

Technical Support in Cognitive Science Laboratory

Supported technical and software side of cognitive science research, especially eye tracking and fNIRS research.

Kostki - Indie Logic/Puzzle PvP Game on Android

A logic/puzzle game featuring player vs. player and player vs. bot modes, with a back-end built in Python Tornado and a bot AI based on projective simulation.
2009 - 2014

Master's Degree in Computer Engineering

AGH University - Kraków


Google API, Android API, Volley Android Library


PyCharm, Git, Weka, Emacs, Android Studio


iOS, Android, Linux, JavaFX


Java, Python, Bash, R, Octave


Swagger, Android SDK, Spring, ORMLite


SQLite, PostgreSQL


REST, Model View Controller (MVC)


Front-end, GNU, Machine Learning

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