I’m Marek
Software Architect, FullStack Developer, Engineer, and Much more

Using the technology we can achieve our goals faster, easier and more effectively. Choosing the right solution is critical for solving the problem in the right way!

About Me

I am a software architect, software developer, engineer, web developer, embedded programmer, machine learning engineer, domain analyst, math enthusiast... The FullStack all the way! And much more! I am just doing what must be done to achieve the goal. I am fascinated by solving problems through application of technology. Building the solution that can help to make life easier is very fulfilling.

I love learning new skills!
Gaining knowledge is absolutely cool!

I treat every task as an opportunity for gaining new knowledge. There is not one supreme technology (for now) or way to get "the things done". Every approach has strong pluses and flaws. For instance, neural networks are great for many tasks but many of them are not suitable for embedded devices with limited resources.

A solution always should help achieve goals of higher purpose than the solution itself!

It is my view that the solution should always help achieve higher goals than the solution itself. For example, the hospital (The Product owner) ordering the new solution (IT system or medial equipment) that is more user friendly, wants not only to get the "better" solution; they want to be more productive and react faster in emergency situations!


When under a huge load, it is very easy to forget to enjoy your work :)



Awesome Bongo Cat Codes by Caroline Artz @carolineartz

Skills

Programming Languages

Java, Kotlin, C#, Python, C/C++, JavaScript, TypeScript

Business Analysis

UML, Archimate 2.0, ERD - entity relationship diagrams



Technologies and Tools

Java Native Interface, Swing, maven, SpringBoot, Hibernate, JUnit

React, React Redux, Node.js, express.js, jQuery, ejs

ASP.NET CORE, ASP.NET MVC, Razor Views, Razor Pages, .NET Framework,
LINQ, EntityFramework,MassTransit, SignalR

MySQL, Oracle, Microsoft SQL Server, PostgeSQL, sqllite

MongoDB

Heroku, Firebase, Azure

HTML, CSS, SASS, Bootstrap

openCV, TensorFlow, TensorFlowLite

Matlab, Octave, AMPL

OpenMP, OpenACC, OpenCL

git, Docker, REST API, GraphQL

AndroidStudio

Keil uVision

and Much More!



Operating Systems

MacOS, Linux (Debian), Windows

Permits and Documents

Category B driving license

Other

Techstream, MS Office, WPS Office, Libre Office, LaTeX

Advancement of language skills

Timeline

Experience

DoingIT Marek Czelij, Freelance
Software development; business analysis of the client's domain problem; designing IT systems; web development; embedded systems development; tutoring in the field of a broadly understood computer science, digital electronics, control theory
Klarna,
Senior Full Stack, Login Platform
Software development; working with high critical, high scalable, and performant systems, contributing to the existing platforms and solutions; integration of multisystem flows
Klarna,
Senior Full Stack AI developer
Software development; working newest AI solutions; AI agents; external service providers; Integrating AI solutions with existing webapps; Contributing to existing platforms
Aera Payment & Identification,
Full Stack developer
Software development; Working with frontend and backend; Implementing fintech domain flows; Implementing microservices; Working on company systems and solutions; AML awareness; Creating web applications; Working with sensitive data; Working in the manner of PCI DSS software development life cycle; Working in agile methodology
Aera Payment & Identification,
Mobile Application developer, Embedded developer
Software development; Implementing fintech domain flows; Working on company systems and solutions; Creating mobile applications; Working with EMV; AML awareness; Working in the manner of PCI DSS software development life cycle; Introducing new team members to the project; Working in agile methodology
Axa It Solutions,
Axa Ireland,
FullStack developer
Software development; Working on company systems and solutions; Working with web applications and backend; Migrating legacy systems on cloud infrastructure; Introducing new team members to the project; Working in agile methodology
Mitsubishi Electric B.V. Europe,
application department,
CC-link specialist
Creating the applications based on the newest CC-link technology solutions; Providing trainings for the team
Mitsubishi Electric B.V. Europe,
application department
Creating the applications for the company's clients; creating the demonstration applications; testing the new solutions, improving the existing ones; the customer requirements analysis; integration the customer devices with the Mitsubishi Electric devices; assistance in training; conducting customer training; remote assistance; continuous improvement of knowledge and competence; creating documentation; instructions for the team and customers
Mitsubishi Electric B.V. Europe,
student internship
Getting to know the Mitsubishi Electric's solutions in the field of industrial automation; creating the applications that allowed one to acquire product handling skills

Education

Computer science,
Faculty of Electronics and Information Technology,
Warsaw University of Technology
Specialisation - The Information and decision making systems
Master's Studies
Mechatronics
Faculty of Mechatronics and Aviation,
Military University of Technology
Specialisation - Automation and control
Engineer Degree
The diploma thesis was written under direction of a mathematician from the University of Warsaw.





Thesis

Face detection algorithms in image and their implementation in the embedded systems
An overview of algorithms and methods of face detection in embedded devices





Courses

Payments


  • UL EMV Contact Contactless Masterclass
  • Payments foundations

IT


  • Software Architecture Training Program - Ongoing
  • IBM AI Engineering
  • IBM Generative AI Engineering
  • Ingenico Tetra Telium 3 Developer Training
  • The Complete Web Development Bootcamp
  • Complete C# Masterclass
  • Java Programming Masterclass for Software Developers
  • The Ultimate Full-stack .NET Developer: Part 1, Part 2, Part 3
  • Complete ASP NET MVC Web Development - Newbie to Ninja
  • The Ultimate Data Structures & Algorithms Series: Part 1, Part 2, Part 3
  • The Ultimate C# Series: Part 1, Part 2, Part 3
  • The Ultimate Design Patterns Series: Part 1, Part 2
  • Design Patterns in Java
  • Microsoft Azure, SCRUM and MicroServices with .NET
  • Master ASP.NET MVC Core 3.1
  • Building Microservices Using ASP.NET CORE 5.0 and Docker
  • Complete React Developer (w Redux, Hooks, GraphQL)
  • Advanced Java Programming

Industrial Automation


  • The Operation, programming and configuration of The Mitsubishi Electric's industrial robots
  • The Operation, programming and configuration of the Mitsubishi Electric's FX5 and iQ-R series PLC's
  • The Operation, programming and configuration of the Mitsubishi Electric's GOT2000 panel series
  • The Operation, programming and configuration of the Mitsubishi Electric's FX5 PLC + simple-motion with MRJ4 servo
  • The Operation, programming and configuration of the Mitsubishi Electric's A800 inverter series
  • CC-link basic, CC-link IE Field, MR-J4-GF - Full Training, Mitsubishi Electric
  • Mitsubishi Motion Controller - basic training

Projects

Portfolio 1

Halmoia

Portfolio 1

Graph traversal AI agent

Portfolio 1

Product Data retriever AI agent

Portfolio 1

LLM Orchestrator AI agent

Portfolio 1

Chatbot webapp integration

Portfolio 1

WebSearch tool for LLM

Portfolio 1

Gemini AI Gateway

Portfolio 1

Emotion detector web app

Portfolio 1

Job Application Coach

Portfolio 1

Babel Fish Translator

Portfolio 1

Voice Assistant

Portfolio 1

Chatbot with RAG

Portfolio 1

Business AI Meeting Companion

Portfolio 1

Personal assistant

Portfolio 1

Acquirer communication plugin

Portfolio 1

Foundations for RAG application

Portfolio 1

Revenue graph web application

Portfolio 1

Payment application

Portfolio 1

Contacting acquirer and submitting merchant agreement

Portfolio 1

Microsystem for generating agreements

Portfolio 1

Merchant onboarding flow

Portfolio 1

Internal content management system

Portfolio 1

Converting monolith system to microservices in the cloud

Portfolio 1

FacesAndFaces

Portfolio 1

The Travel Agency

Portfolio 1

The Customer WebApi Microservice

Portfolio 1

Book publishing house

Portfolio 1

My eCommerceShop

Portfolio 1

Vehicle identification and localisation

Portfolio 1

face detection task support

Portfolio 1

The Bitcoin-Ticker

Portfolio 1

The MyToDoList

Portfolio 1

Segregation of details by volume

Portfolio 1

users' parameters database

Portfolio 1

Dynamic Time Warping

Portfolio 1

The AFAUFD

Portfolio 1

The Sugar-weighing station

Portfolio 1

The store database

Portfolio 1

shampoo packaging packing station

Portfolio 1

compilation of kernel of the RTLinux

Portfolio 1

reducer

Portfolio 1

gripper for insulin pen

Portfolio 1

compressor first A800E in Poland

Portfolio 1

The tea bag production

Portfolio 1

GSM modem

Portfolio 1

train wagons/cars length measurement

Portfolio 1

traverse movement measurement module

Portfolio 1

display controller

Portfolio 1

LQ controller

Portfolio 1

Database of the household appliance service provider

Portfolio 1

Screw jack