Adam Stelmaszczyk, Developer in Warsaw, Poland
Adam is available for hire
Hire Adam

Adam Stelmaszczyk

Verified Expert  in Engineering

Algorithms Developer

Warsaw, Poland
Toptal Member Since
September 14, 2017

As a curiosity-driven constant learner, Adam is interested in mathematics, computer science, and artificial intelligence. Having come across programming at a very young age, he grew up solving problems and especially enjoys it when the solutions involve creativity. A good communicator and people person, Adam has a good eye for detail. He has worked in teams of all sizes and actively participates in open source and AI competitions.


Google Ads, Facebook Ads, Google Cloud, BigQuery, MongoDB, Git, Python...
GridCell (via Toptal)
Python, Google Cloud, TensorFlow, Deep Reinforcement Learning
Smarkets, Hanson Applied Sciences
Amazon Web Services (AWS), BigQuery, PostgreSQL, GitLab, Jenkins, Docker, Flask...




Preferred Environment

PyCharm, Vim Text Editor, Git, Linux, GNU

The most amazing...

...thing I've done is teach a human model how to walk using deep reinforcement learning and 80 CPUs.

Work Experience

Machine Learning Engineer

2018 - 2018
  • Optimized Facebook and Google ads.
  • Devised and implemented five ads optimization algorithms, with one showing a significant improvement.
  • Introduced and automatized split testing to compare the algorithms fairly.
  • Contributed to the jobs architecture, code repository structure, reviewed code, and helped others.
  • Designed, conducted, and analyzed experiments, prepared technical reports and a strategy for next steps.
  • Devised a way to find similar campaigns and to have even more data to leverage.
  • Conducted 1-hour AI learning session for 15 people.
Technologies: Google Ads, Facebook Ads, Google Cloud, BigQuery, MongoDB, Git, Python, Monte Carlo, Testing, Mathematics

Machine Learning Specialist

2017 - 2018
GridCell (via Toptal)
  • Implemented custom reinforcement learning environments in Python compatible with OpenAI gym.
  • Tested various deep reinforcement learning algorithms such as DQN and PPO.
  • Deployed, trained, and hyperparameter tuned models on Google Cloud Machine Learning Engine.
  • Provided technical advice.
  • Documented every step and environment detail needed to reproduce the experiments.
  • Learned about Differentiable Neural Computers and implemented new training task in the DeepMind's code.
Technologies: Python, Google Cloud, TensorFlow, Deep Reinforcement Learning

Software Engineer

2015 - 2017
Smarkets, Hanson Applied Sciences
  • Collaborated on research, design, and implementation of state-of-the-art market pricing algorithms.
  • Partnered in research, design, and implementation of anti-fraud micro-service for auto flagging suspicious activity, using Random Forests.
  • Increased the trading performance N times by parallelizing computations onto N shards.
  • Discovered, wrote tests, and fixed multiple severe bugs. Fixed more than a 100 smaller ones.
  • Proposed an idea and wrote a hybrid mobile app that replaced the old native one completely, thanks to that we had only one codebase and team instead of three (web, Android, iOS).
  • Conducted 57 technical in-person interviews, introduced online coding tests which more than 1000 candidates took, devised a method for auto grading, introduced employee referral scheme that brought more than 5 excellent new employees to the company.
  • Worked in a self-management setting in a period of a rapid development (from 28 to over 90 employees), contributed to Smarkets growth and culture.
Technologies: Amazon Web Services (AWS), BigQuery, PostgreSQL, GitLab, Jenkins, Docker, Flask, Bash, Linux, GNU, Haskell, Scikit-learn, Pandas, NumPy, IPython, SciPy, Python, Machine Learning

Cohort Member

2015 - 2015
Entrepreneur First
  • Accepted to the EF4 cohort consisting of 36 top tech people throughout Europe. There were 1200 applicants.
  • Collaborated with other members to conceptualize ideas.
  • Created SportsTracking proof of concept, an automatic extraction of statistics from sport videos using image recognition (Python, OpenCV).
  • Built prototype of BitVisual, a visualization of Bitcoin transactions (Neo4j graph database).
  • Developed first version of, a marketplace for translators (Scala, Play Framework).
Technologies: Scala, Bitcoin, Neo4j, OpenCV, Python

Software Engineer

2014 - 2015
  • Implemented core functionalities of Store Intelligence Android application in a team of 4.
  • Developed features for identity system for Flemish Government using Wicket (Java) in a team of 5.
  • Fixed several reported issues in the back-end of large Java EE system for Polish Ministry of Health.
  • Built a mobile hybrid application written in AngularJS and packed with Cordova for Android. Introduced Jenkins for automatic builds, which saved us about 5% of time everyday and resulted in less context-switching.
  • Conducted video-recorded, 1-hour Brown Bag Seminar titled "Android: basics, tips & tricks" to an audience of 30 people.
  • Co-organized HP Developer Day, brand-new, one-day programming competition for Polish developers. 2014 event gathered 40 selected participants and met with a very positive feedback.
Technologies: Jenkins, Android, Java

Android Freelance Developer

2012 - 2012
  • Gathered requirements, met and communicated with a client.
  • Implemented Android financial application which provided live share and corporate bond prices, plus a list of company announcements, dedicated to the Maltese listed market.
  • Advised and deployed finished product to the Google Play market.
Technologies: Java, Android

Software Engineer Intern

2011 - 2011
  • Implemented part of S Pen Library and developed demo app.
  • Wrote a tutorial + an exemplary game showing how to use the camera in Samsung Linux Platform (now Tizen).
Technologies: Java, Android, C++, C

Junior Programmer

2009 - 2009
  • Joined a startup (2 people at that time) to learn while developing websites such as and
Technologies: Drupal, PHP, JavaScript, CSS, HTML

Game Tree Search Algorithms
C++ library for AI bot programming, useful in competitions.

Shield for Clash of Clans

Winner of Hack & Tell #2 London:

Utility/hack for Clash of Clans, one of the most popular mobile games ever. It received 1000 installs after just 12 days and another 1000 installs after only 6 days through word of mouth between players. So far it has been installed on 200,000 devices in the world and counting.

Swipe Master 2: Space

Android game developed over the course of a year as a personal project. Swipe Master has been installed on more than 30,000 devices in the world. It wasn't our primary goal, fun and learning were, but we even earned some money on ads.

++C Programming Language

Dynamically typed C. I also made string manipulation more convenient by making the string a built-in type. Also removed the need for declarations being before definitions, which is annoying in original C.

For proof of concept, I wrote ++C to C++ translator (in C++, using Flex and Bison).

10th (out of 4014) in Halite 3

During 3 months of competition, I created an AI bot in C++ that reached top 10.

4th (out of 880) in Battle of Bots #3
During 1 week of competition, I created an AI bot in C++ that reached 4th place.

7th (out of 2700) in IndiaHacks: Bot Challenge
During 1 week of competition, I created an AI bot in C++ that reached 7th place.

Distinction on Engineer's Thesis from Warsaw University of Technology

Thesis title: "Tool for detecting similar program code fragments."

Top 3% Overall on Stack Overflow
Sorted by reputation points I'm in top 9000 users.

Our NIPS 2017: Learning to Run Approach

For three months, from July to November 13, a friend and I participated in the NIPS 2017: Learning to Run competition. In this publication, we describe our experience.

Skills: Deep reinforcement learning, TensorFlow, physics-based simulation


C++, Python, Java, SQL, R, C, HTML, CSS, JavaScript, PHP, Octave, Assembler x86, Bash, Scala, Haskell


JUnit, Swagger, Bootstrap, Django, Boost, Flask, Play Framework, Caffe


GitLab, Shell, Git, OpenAI Gym, Jenkins, PDB, GDB, Vim Text Editor, PyCharm, IPython, BigQuery


Data Science, Object-oriented Programming (OOP), Continuous Integration (CI), Test-driven Development (TDD), Unit Testing, REST, Testing, Functional Programming


Linux, Drupal, Google Cloud Platform (GCP), Heroku, Amazon Web Services (AWS), Docker, Android


Game Theory, Optimization, Reinforcement Learning, Evolutionary Algorithms, Neural Networks, Software Development, Machine Learning, Deep Learning, Data Structures, Artificial Intelligence (AI), Algorithms, Genetic Algorithms, Research, Software Engineering, Bitcoin, Statistics, Mathematics, GNU, Deep Reinforcement Learning, Monte Carlo, Facebook Ads, Google Ads, Compilers, Security


Keras, TensorFlow, NumPy, Pandas, Standard Template Library (STL), Scikit-learn, Matplotlib, SciPy, OpenCV


MySQL, PostgreSQL, Neo4j, Google Cloud, MongoDB

2017 - 2018

Progress Toward a Ph.D. in Artificial Intelligence, Deep Reinforcement Learning

University of Warsaw - Warsaw, Poland

2013 - 2014

Master's Degree in Artificial Intelligence

Warsaw University of Technology - Warsaw, Poland

2009 - 2013

Engineer's Degree in Computer Science

Warsaw University of Technology - Warsaw, Poland

2011 - 2012

Engineer's Degree in Computer Science

University of Malta - Malta


Oracle Certified Professional, Java SE 6 Programmer


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.


Share your needs

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

Choose your talent

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

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