Błażej Kotowski, Developer in Linz, Austria
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Błażej Kotowski

Verified Expert  in Engineering

Software Developer

Location
Linz, Austria
Toptal Member Since
November 10, 2016

As someone who's been passionate about computer science since his tender years, Błażej has a lot of experience with various languages. The area that he chooses to work in mainly is back-end programming. He loves to craft perfect solutions, focusing on detail and reliability. Although Błażej likes to learn new things and take on challenges, he also finds much satisfaction in polishing up his skills.

Portfolio

[Enterprise] Asset Panda LLC
Ruby on Rails (RoR), RSpec, MongoDB, PostgreSQL, Amazon Web Services (AWS)...
BigMedia.ai
HTML, CSS, RSpec, Capybara, Heroku, JavaScript, Ruby on Rails 5, Algorithms...
Advisor Analytics, LLC
Amazon Web Services (AWS), Python 3, CSS, HTML, JavaScript, GoCD, Terraform...

Experience

Availability

Part-time

Preferred Environment

Git, Zsh, Visual Studio Code (VS Code), MacOS, Linux, Vim Text Editor

The most amazing...

...thing I've coded is a visualization and sonification of the evolutionary simulation of aquatic life.

Work Experience

Database Architect | Senior Back-end Developer

2021 - PRESENT
[Enterprise] Asset Panda LLC
  • Worked on the legacy codebase of an existing application to reduce the page load times drastically—in some cases, more than ten times.
  • Increased modularity of the code by applying concepts like the single-responsibility principle or separation of concerns. Introduced PORO classes like services and query objects.
  • Wrote and maintained a comprehensive coding standards guide document to be followed strictly by all the back-end developers in the team.
  • Oversaw the work of up to five developers, planning the tasks, conducting detailed code reviews, and organizing regular code walkthroughs and training sessions.
  • Designed a MongoDB database architecture from scratch for migrating the legacy data to the new application with a more optimal data model. The design process was conducted in consultation with MongoDB data modeling experts.
Technologies: Ruby on Rails (RoR), RSpec, MongoDB, PostgreSQL, Amazon Web Services (AWS), Data Modeling, Performance, Algorithms, Server Administration, Data Structures, Object-oriented Programming (OOP), Linux, Vim Text Editor, Databases

Full-stack Developer

2020 - 2020
BigMedia.ai
  • Collaborated with an international team of freelancers on developing a suite of apps for collaborative video creation. Used Pivotal Tracker for task management and bug tracking.
  • Created a cost-effective, on-demand Zoom users and meetings management system using Ruby on Rails and the Zoom Business API. Supported automatic profile creation, syncing between environments, and setting the maximum spending limit.
  • Used GitHub and contributed the code for several API endpoints to one of the most popular open-source Zoom API client gems. Helped identify bugs and provide solutions.
  • Helped develop a novel live streaming platform allowing for remote filming during the COVID-19 crisis. Supported multi-camera shooting and live state updates using Action Cable.
  • Developed and maintained a comprehensive base of automated unit and integration tests using Capybara and RSpec. Implemented a custom testing helper for simulating API interaction based on JSON response fixtures.
Technologies: HTML, CSS, RSpec, Capybara, Heroku, JavaScript, Ruby on Rails 5, Algorithms, Server Administration, Data Structures, Data Modeling, Object-oriented Programming (OOP), jQuery, Vim Text Editor

Full-stack Developer

2019 - 2020
Advisor Analytics, LLC
  • Used Terraform, provisioned an AWS infrastructure based on Elastic Beanstalk, and then deployed the app. Used custom security groups and a PostgreSQL RDS machine.
  • Created a custom payment page for the client's product. Integrated PayPal with a custom payment flow and the Stripe online payment gates.
  • Iteratively implemented several requested changes in the page's design using JavaScript, Webix, HTML, and CSS.
  • Provisioned a separate EC2 machine within the infrastructure for a continuous delivery tool, GoCD. Created and managed testing and deployment pipelines with custom tasks provided in the form of bash scripts.
  • Developed and maintained the integration tests for the most important product features using RSpec and Capybara.
Technologies: Amazon Web Services (AWS), Python 3, CSS, HTML, JavaScript, GoCD, Terraform, Django, Python, Server Administration, Data Structures, jQuery, Vim Text Editor

Researcher | Full-stack Developer

2018 - 2020
MusicCritic — Music Technology Group (MTG)
  • Maintained and developed an AI-driven web application for music practice teaching and automatic assessment. Implemented an API in compliance with the LTI standards.
  • Helped prepare the pilot music teaching courses and led the technical integration with one of the biggest available MOOC platforms offering courses geared toward art, music, and creative technology.
  • Coordinated a team of five music-technology and machine-learning doctoral researchers to integrate their research work into an existing web application.
  • Built a standard and a guide for creating add-on AI modules to be easily installed into the application within the Django code.
  • Prepared and executed a series of experiments to deal with the complexity of audio latency in the Web Audio API. By introducing optimizations, I reduced the recording app's latency significantly.
Technologies: NGINX, Web Audio API, Docker, Django, Python, Algorithms, Server Administration, Data Structures, Data Modeling, Object-oriented Programming (OOP), jQuery, Linux, Vim Text Editor

Ruby on Rails Developer

2017 - 2018
Clustrix
  • Worked in a team of three to extend and maintain an admin interface consisting of a DBI app and GUI app for an existing scaled-out RDBS product.
  • Optimized several complex MySQL queries generated by Rails to perform better in the product-specific environment and database.
  • Upgraded two Rails apps with 20,000+ lines from Rails 4 and Ruby 2.2 to Rails 5 and Ruby 2.5.
  • Refactored cluttered parts of code, introducing modern Rails concepts like services and concerns.
  • Created and maintained tests for already existing and only introduced features.
Technologies: MySQL, JavaScript, Bash, Ruby on Rails (RoR), Server Administration, Data Structures, Data Modeling, Object-oriented Programming (OOP), Linux, Vim Text Editor, Databases

Ruby on Rails Developer

2016 - 2017
22Fours/Synnaps
  • Improved the code performance of an existing Ruby on Rails application.
  • Developed an application that connected the parties involved in solving a refugee crisis.
  • Adapted the existing Ruby on Rails code to three language versions.
  • Implemented a couple of themes into the existing Ruby on Rails applications.
  • Created a complex booking management system using RoR.
  • Configured a lot of servers for various Ruby on Rails environments.
Technologies: Redis, Ruby on Rails (RoR), Ruby, Server Administration, jQuery, Vim Text Editor

Full-stack Developer

2015 - 2015
SI Labs GmbH
  • Constructed a library for scraping data from major German energy companies' APIs and websites.
  • Created a location-based heuristic solution for expense optimization based on energy companies' offers and reports.
  • Developed a solution generating PDF documents based on input data from many sources.
  • Took part in designing the company's IT infrastructure.
  • Maintained an application according to very strict security instructions.
  • Contributed to the concept stage of designing innovative solutions.
  • Built the fundaments for and maintained an Android application.
Technologies: Python, Ruby on Rails (RoR), Ruby, Server Administration, Data Structures, Object-oriented Programming (OOP), jQuery, Linux, Vim Text Editor

Ruby on Rails | PHP Analyst

2015 - 2015
teNeues
  • Analyzed the condition and integrity of various Ruby on Rails applications.
  • Analyzed the hardware and software setup of application servers.
  • Analyzed various databases structure to assess the optimality of their design.
  • Updated the code and fixed some major performance issues.
  • Created a comprehensive rapport of code condition, possible code part usage, test coverage, and explanations of application behavior.
Technologies: JavaScript, PHP, Ruby on Rails (RoR), Ruby, Vim Text Editor

Web Developer

2014 - 2015
Restaurant Partner Polska Sp. z.o.o
  • Created various marketing-related, data-based applications.
  • Implemented graphic designs.
Technologies: JavaScript, PHP, Ruby on Rails (RoR), Ruby, jQuery, Vim Text Editor

Android and Web (RoR) Application Developer

2013 - 2014
TheCheck.in
  • Created an Android map-based application serving data from API.
  • Maintained a Ruby on Rails application based on NoSQL database, storing large amounts of location-based data.
  • Supported a Backbone.js application serving data from the API.
  • Set up an application and database server.
Technologies: MongoDB, Ruby on Rails (RoR), Ruby, Java, Vim Text Editor

Chief Technology Officer

2012 - 2013
Kipscore.com
  • Created a web application for tournament organizing.
  • Implemented an automatic payment system.
  • Constructed a web scraper library—scraping sports players data from external websites.
  • Developed a C application for serving the scraped data quickly.
  • Built a WebSockets solution for observing the tournament progress.
  • Designed and implemented a W3C valid website design.
  • Created a Facebook application for joining and displaying the tournaments.
Technologies: C, Redis, Ruby on Rails (RoR), Ruby, Server Administration, Data Structures, Data Modeling, Object-oriented Programming (OOP), jQuery, Linux, Vim Text Editor

Chief Technology Officer

2011 - 2013
Jourmie.com
  • Created a website application managing media storage.
  • Implemented a graphic design.
  • Executed an application and database environment.
  • Configured a domain with a SSL certificate.
  • Created a secure data storage system.
Technologies: Redis, Ruby on Rails (RoR), Ruby, Server Administration, Data Structures, Data Modeling, Object-oriented Programming (OOP), jQuery, Linux

Web Developer

2009 - 2011
Mebella.pl
  • Designed a W3C-valid website layout.
  • Created a CMS.
  • Configured the domain and hosting.
  • Maintained the website changes.
Technologies: Kohana, PHP, Server Administration

Latent Space Divination

Latent Space Divination is ongoing research and a series of experiments using different media, dealing with the epistemological implications of the computational revolution in the form of deep learning techniques that have led to the GPT-3 natural language model. The investigation focuses on the convoluted, numerical latent representations of knowledge held within the circuitry of the AI model, the inner workings of the algorithm itself, as well as the belief systems and sociocultural conditions underlying the emergence of the technology.

Master Thesis: Dualization of Rhythm Patterns

https://zenodo.org/record/4091469
A two-year-long research project on a novel research-oriented task of rhythm dualization. For this task, I have worked with and developed new state-of-the-art deep neural networks. Designed architectures based on sequence-to-sequence learning and autoencoding. Constructed a dataset for the task and worked with data augmentation, feature extraction, dimensionality reduction, etc. The task also included comprehensive theoretical research on human rhythm cognition.

Preferly

Preferly is a platform for referral marketing. The biggest part of it is an API for integrating user applications. It enables users to track customer referrals, generates statistics, and takes care of mailing. It also implements a complex anti-fraud system detecting system abuse attempts. There is also a WooCommerce plugin—written in PHP for implementing Preferly straightforward into an existing eCommerce based on WordPress.

Jourmie

Jourmie is a modern, interactive travel social network that I built from scratch. Besides having well-known social features like friends, private messaging, commenting, and so on—it provides a new approach to content creation. It integrated many different technologies like library media storage and conversion and WebSockets for real-time communication or Facebook, Twitter, and Google+ connections.
2018 - 2020

Master's Degree in Sound and Music Computing

Universidad Pompeu Fabra - Barcelona, Spain

2011 - 2014

Bachelor's Degree in Computer Science

Poznan University of Technology - Poznan, Poland

SEPTEMBER 2021 - PRESENT

Data Modeling

MongoDB University

SEPTEMBER 2021 - PRESENT

MongoDB Performance

MongoDB University

SEPTEMBER 2021 - PRESENT

The MongoDB Aggregation Framework

MongoDB University

SEPTEMBER 2021 - PRESENT

MongoDB Basics

MongoDB University

MAY 2021 - PRESENT

Blockchain Developer

Coursera

Frameworks

Ruby on Rails (RoR), Django, Kohana, Ruby on Rails 5, Capybara, Truffle

Tools

RSpec, Capistrano, Yeoman, Vim Text Editor, Git, Sublime Text, Zsh, NGINX, Docker Compose, Terraform, MongoDB Shell, MongoDB Atlas

Paradigms

Object-oriented Programming (OOP), Agile Software Development, Scrum, Concurrent Programming, Functional Programming, Data Science

Other

Sound Design, Data Modeling, Algorithms, Data Structures, Music Production, Server Administration, Performance, GoCD, Music Information Retrieval (MIR), Digital Signal Processing, Deep Learning, Machine Learning, Artificial Intelligence (AI), Technical Writing, Coding, Deep Neural Networks, Art, Data Visualization, Data, Dimensionality Reduction, DApps

Languages

Python, JavaScript, C, Ruby, Java, Bash, HTML, CSS, Python 3, C++, PHP

Libraries/APIs

jQuery, Ruby on Rails API, Web Audio API, Facebook API, TensorFlow, Pandas, Web3.js

Platforms

Amazon Web Services (AWS), MacOS, Linux, Unix, Heroku, Oracle, Docker, Blockchain, Visual Studio Code (VS Code)

Storage

MongoDB, PostgreSQL, Redis, MySQL, Amazon S3 (AWS S3), Databases

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