Bartłomiej Patrzyk, Developer in Kraków, Poland
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Bartłomiej Patrzyk

Verified Expert  in Engineering

Full-stack Developer

Kraków, Poland
Toptal Member Since
February 18, 2020

Along with being passionate about cloud computing, Bartłomiej is a proficient full-stack developer with over a decade of experience in software development and industrial automation. He has worked in teams of various sizes in both startup and corporate environments. With robust problem-solving skills and a proactive approach, Bartłomiej always delivers beyond what is expected.


Freelance Client
React, .NET 6, C#, C#.NET, JavaScript, Redux, D3.js, Mapbox, Mapbox SDK...
Software Mansion
Amazon Web Services (AWS), Bitrise, MongoDB, PostgreSQL, Java, Kotlin, Node.js...
Branchspace (via Software Mansion)
Amazon Web Services (AWS), Oracle Database, Jenkins, Ansible, Terraform...




Preferred Environment

Jira, Postman, IntelliJ IDEA, WebStorm, Linux, GitHub

The most amazing...

...thing I've built was a precise control system for manufacturing machines with an innovative temperature control algorithm that increased machine productivity.

Work Experience

Senior Software Developer

2020 - 2023
Freelance Client
  • Developed a crop and field management system with a rich presentation layer (interactive maps, charts, and dashboards).
  • Created a crop growth model based on the agronomists' recommendations.
  • Implemented a sophisticated farming activities recommendations engine aimed at helping the growers schedule their work throughout the growing season.
  • Built an integration with IoT LoRa devices (pumps, valves, soil moisture sensors, water level sensors, and flow meters).
  • Implemented a synchronization service between a legacy SQL database and the application.
  • Conducted research and feasibility studies regarding the availability and possibility of integration with existing agronomical APIs (weather radars and soil texture maps).
  • Participated in the UI/UX and product design process.
Technologies: React, .NET 6, C#, C#.NET, JavaScript, Redux, D3.js, Mapbox, Mapbox SDK, Azure Cosmos DB, SQL, SQL Server 2016, Azure DevOps, Git, HTML, CSS, Material UI, IoT Protocols

Senior Software Engineer | Architect

2017 - 2019
Software Mansion
  • Led the migration from a legacy Java monolith deployed on AWS to Kotlin microservices deployed on Heroku.
  • Supervised the refactoring and technical debt mitigation in a legacy React Native app.
  • Configured CI/CD pipelines on CircleCI, Bitrise, and Jenkins for back ends, front ends, and mobile apps (both native Android/iOS and React Native).
  • Designed, configured, and automated infrastructures on AWS and Heroku.
  • Conducted technical interviews for software developer and DevOps roles (from intern to senior).
  • Prepared tutorials and mentored participants at React Native and Expo workshops.
Technologies: Amazon Web Services (AWS), Bitrise, MongoDB, PostgreSQL, Java, Kotlin, Node.js, JavaScript, React Native, React, REST, Git, CSS, HTML, SQL, Terraform, Ansible, Heroku, Full-stack

Senior Software Developer

2016 - 2018
Branchspace (via Software Mansion)
  • Developed a highly customizable digital platform for the airline and travel industries.
  • Designed, configured, and maintained the system infrastructure on AWS using Terraform and Ansible.
  • Developed a set of web apps for company data management, all of which used Shibboleth for single sign-on.
  • Mentored teammates on AWS and DevOps and held internal workshops.
  • Analyzed customer requirements and prepared development documentation.
  • Helped to optimize the scrum process by suggesting means to better organize the planning meetings, such as doing the backlog grooming and preparing the meeting agenda in advance.
Technologies: Amazon Web Services (AWS), Oracle Database, Jenkins, Ansible, Terraform, Amazon Virtual Private Cloud (VPC), Amazon EC2, Amazon S3 (AWS S3), React, JavaScript, MongoDB, Spring, Java, Git, SQL, REST, HTML, CSS, Full-stack

Senior Software Engineer

2015 - 2017
Software Mansion
  • Implemented full-stack solutions, mostly with a Java or Node.js back end and a React front end.
  • Set up infrastructures and deployed apps on AWS or Heroku.
  • Mentored junior and mid-level developers and helped them quickly get up to speed.
Technologies: Amazon Web Services (AWS), Jenkins, Docker, Heroku, MongoDB, Spring, Java, Node.js, JavaScript, React, SQL, REST, Git, Express.js, HTML, CSS, Full-stack

Software Engineer

2015 - 2016
Node1 (via Software Mansion)
  • Implemented a Node.js SOAP service that worked as a type of middleware between two legacy systems. The application periodically imported data stored in AWS S3 into a MySQL database and exposed it with a SOAP API.
  • Deployed services on Heroku and configured metrics and alerts.
  • Monitored the services and provided support in case of failures.
Technologies: Amazon S3 (AWS S3), Heroku, SOAP, Sequelize, MySQL, Node.js, JavaScript, Git, REST, Express.js, SQL

Contract Software Developer

2015 - 2015
Sabre Corporation
  • Implemented front-end and back-end features for a configurable eCommerce platform.
  • Developed and maintained an in-house test automation framework.
  • Worked with QA team on resolving the defects and helped create test scenarios.
Technologies: YUI, JavaScript, SOAP, Oracle Database, Hibernate, Spring, Java, REST, JavaScript Debugging, Full-stack

Software Engineer

2014 - 2015
Software Mansion
  • Worked on various native Android apps with Facebook and Twitter integrations, Google Maps, OpenStreetMap, QR code scanner, and Socket.IO.
  • Analyzed customer requirements and created and estimated user stories.
  • Prepared Android apps for publishing, monitored apps that were in production, and resolved the defects.
Technologies: Robospice, Retrofit, Fabric, Crashlytics, Instabug, Android SDK, Java, Google Maps, Google Maps SDK, Git, REST, Android

Industrial Automation Specialist

2008 - 2014
Termo Automatyka
  • Designed, built, and programmed an automation system for fuel hose thermoforming machines.
  • Created functional requirements and designed a control system for a water treatment plant.
  • Designed and implemented a heat recuperation system that preheated process water using excessive heat from steam condensate.
  • Implemented PID controllers for several heating substations that optimized energy consumption.
Technologies: PHP, Java, Ladder Logic, PLC, JavaScript, Modbus Protocol, Siemens PLC, Automation Tools, Human-machine Interface (HMI)

Crowdsourcing App

A crowdsourcing app for a developing country market where users could perform various tasks in exchange for a reward. The mobile app was available for Android and iOS and developed in React Native. The back end was leveraged with Java and Kotlin with the Spring Boot framework. The data was stored in MongoDB and PostgreSQL databases.

Technologies: Java, Kotlin, Spring Boot, Hibernate, MongoDB, PostgreSQL, JavaScript, React Native, Heroku, AWS (S3, Elastic Beanstalk, EC2, VPC), CircleCI

Digital Platform for the Travel Industry

The project's primary objective was to design and build a highly customizable eCommerce platform for the airline and travel industries. With Java on the back end and React on the front end, the application was architected to be highly scalable and easily extensible to facilitate the needs of different customers.

Technologies: Java, Spring, MongoDB, JavaScript, React, Redux, AWS (VPC, EC2, S3, ElastiCache), Terraform, Ansible, Docker, Jenkins

Internal Corporate Portal

The project's main goal was to create a central place where the employees could manage critical business data. The application needed to be integrated with existing systems and tools. The back end was implemented in Java, and the front end was implemented in React. The application included SAML single sign-on that was integrated with Active Directory.

Technologies: Java, Spring, Hibernate, Oracle Database, JavaScript, React, Redux, AWS (VPC, EC2, S3), Shibboleth, Jenkins

SAP SOAP Middleware

A robust SOAP API implemented in Node.js with a MySQL database that acted as a type of middleware between SAP and a legacy ERP application. The back end periodically imported data from the SAP database and exposed it to the front-end application used by the operations team. The biggest challenge was to ensure data integrity and optimize database queries.

Technologies: JavaScript, Node.js, MySQL, Sequelize, Heroku, AWS S3

Control and Visualization Tool for the HVAC Industry

A web app for controlling and visualizing the state of AC/ventilation units. It allowed the users to change the machine's parameters and state manually or using simple automation rules. The application leveraged the Modbus protocol for communicating with the Unit's PLC.

Tour Guide App

The app was designed to guide tourists through the trails of a landscape park. Users can access interactive educational content about local fauna and flora by scanning QR codes found on the trail. The app also contained a quiz where users could test their knowledge and compete with other tourists.

Technologies: Android, OpenStreetMap, Retrofit, RoboSpice, QR code scanner

Training App

A mobile app intended for people who are looking for training buddies. It allows users to search for other users interested in the same sports disciplines and arrange to train together. It also made it possible to browse sports events that were taking place near a user's location.

Technologies: Android, Google Maps SDK, Retrofit, RoboSpice

Event Finder App

An Android app that allowed users to look for interesting events near their location. The app included social media features such as friends lists, in-app chats, and check-in functions. Moreover, the application allowed the user to notify their friends in case of an emergency and included a simple navigation feature in case one got lost. Furthermore, it allowed business owners to promote their events by giving users free vouchers and notifying them about new promotions.

Technologies: Android, Google Maps SDK, Retrofit, RoboSpice

Shor’s Algorithm Simulation

Shor’s factoring algorithm is one of the fundamental algorithms in quantum computer science. For my master’s thesis, I implemented the simulation of multiple optimization variants of the algorithm and analyzed their performance.

Technologies: C#

A Control System for Fuel Hose Manufacturing Machines

A programmable logic controller (PLC) program that controlled machines that built car fuel hoses. The main objective of the software was to precisely control the heating and cooling of the part and the movement of the actuators that were installing hose connectors. With a custom temperature control algorithm, it was possible to reduce the overall process duration and increase productivity. The program was developed in compliance with internal quality assurance standards and health and safety regulations.

Technologies: PLC, Ladder Logic, Modbus
2013 - 2014

Master of Science Degree (Honors) in Computer Science

AGH University of Science and Technology - Kraków, Poland

2008 - 2013

Bachelor of Engineering Degree in Computer Science

AGH University of Science and Technology - Kraków, Poland


React, Node.js, D3.js, YUI, Fabric, Retrofit, Robospice, Google Maps SDK, Google Maps


Jenkins, Git, Jira, WebStorm, IntelliJ IDEA, Postman, Amazon Virtual Private Cloud (VPC), Instabug, Crashlytics, Knex.js, MongoDB Atlas, CircleCI, Terraform, Ansible, Amazon ElastiCache, Sequelize, Shibboleth, GitHub, Siemens PLC, JavaScript Debugging


Java, JavaScript, SQL, HTML, C#, C#.NET, PHP, TypeScript, Kotlin, CSS, C++, Pascal


Spring, Material UI, Android SDK, React Native, Express.js, Spring Boot, Jest, Hibernate, Redux


REST, Azure DevOps


Amazon Web Services (AWS), Heroku, Amazon EC2, Mapbox, MacOS, Docker, Android, Bitrise, AWS Elastic Beanstalk, Oracle Database, Oracle, Ubuntu, Ubuntu Linux, Apache2, Linux


Amazon S3 (AWS S3), Azure Cosmos DB, PostgreSQL, MongoDB, MySQL, Redis, SQL Server 2016


Full-stack, .NET 6, PLC, Quantum Computing, SOAP, Ladder Logic, OpenStreetMap, QR Codes, SAP, LDAP, Ubuntu Server, Modbus Protocol, Automation Tools, Cisco, Networking, Networks, Neural Networks, Algorithms, CORBA, ICE, Mapbox SDK, IoT Protocols, Human-machine Interface (HMI)

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