Slawomir Mazur, Developer in Warsaw, Poland
Slawomir is available for hire
Hire Slawomir

Slawomir Mazur

Verified Expert  in Engineering

Java Developer

Location
Warsaw, Poland
Toptal Member Since
January 16, 2017

Slawomir is a seasoned engineer with over 15 years of experience delivering high-quality, scalable solutions across diverse domains. Passionate about software architecture, optimization, and algorithms, he excels as a technical lead, lecturer, and trainer. A strong advocate for test-driven development (TDD), Slawomir holds certifications as a Java engineer and AWS architect.

Spring MVCJavaMagentoTest-driven Development (TDD)HibernateJEESpring SecuritySpring BootGitKotlinSoftware EngineeringSoftware DevelopmentLinuxJavaScriptAmazon Web Services (AWS)

Portfolio

STRICTE
Kubernetes, Docker, Spring Boot, Groovy, Kotlin, Java, Spring Security...
CodersLab
Spring, jQuery, JavaScript, Java EE, Java, Hibernate
Picadilla
Spring, Java

Experience

Java - 13 yearsTest-driven Development (TDD) - 10 yearsSpring Boot - 8 yearsSpring Security - 8 yearsAmazon Web Services (AWS) - 7 yearsDocker - 6 yearsKubernetes - 5 yearsKotlin - 5 years

Availability

Full-time

Preferred Environment

Amazon Web Services (AWS), Docker, Kotlin, Java, Spring MVC, Spring Boot, Kubernetes

The most amazing...

...I've created is an innovative AI-driven analytics platform, transforming data for traffic planning, traffic light timing, and sequencing operational efficiency.

Work Experience

Software Engineer | Independent Technology Consultant | Lecturer

2015 - 2024
STRICTE
  • Designed and developed microservice architecture, acting as a senior software engineer. I worked on back-end services communicating through various protocols, including Kafka, SNS/SQS, gRPC, and REST APIs.
  • Planned, designed, and executed the transition of monolithic applications to a microservice/serverless hybrid model using API Gateway and Lambda.
  • Developed, for Siemens in Hong Kong, a real-time pedestrian and traffic tracing and analysis flow—it controlled traffic at junctions with traffic lights using high-throughput IoT and automotive universal medium radar sensors.
  • Collaborated on an NDA project for a German loan enterprise leader, leveraging Java 11, Spring Boot, Cloud, Docker, Kubernetes, and Travis CI.
  • Architected and integrated financial platforms supporting iOS and Android clients for a German loan comparison service, ensuring quick and reliable online loans. This project is under NDA.
  • Integrated Onfido's identity verification API with third-party fraud prevention systems for enhanced security and identity services using Java 11, Spring Boot, Docker, and Kubernetes.
  • Integrated, for CRM suite, dealer management systems for efficient and effective communication, combining social media activities with AI, using Java 8, JAX-WS, JAX-RS, JAXB, and SOAP.
  • Collected, processed, and analyzed real-time, streaming data from an IoT network of over 5 million devices for ISTA, utilizing Java 8, JAX-WS, JAXB, and SOAP.
  • Determined all aspects of development from the applicable technology stack and workflow to coding standards and choosing the system architecture and each individual component and connections between the components of this system.
  • Implemented quality assurance by successfully adapting TDD discipline to daily routines.
Technologies: Kubernetes, Docker, Spring Boot, Groovy, Kotlin, Java, Spring Security, Amazon Web Services (AWS), Google Cloud

Trainer | Consultant

2017 - 2023
CodersLab
  • Developed an innovative curriculum that integrates the latest software engineering practices and technologies, significantly enhancing the educational experience and employability of students.
  • Led a collaborative project between academia and industry, facilitating real-world software development experiences for students, which resulted in the creation of commercially viable applications.
  • Implemented a continuous learning and assessment platform using cutting-edge technologies, improving student engagement and outcomes by providing immediate feedback and personalized learning paths.
Technologies: Spring, jQuery, JavaScript, Java EE, Java, Hibernate

Tech Lead | Senior Java Developer

2016 - 2017
Picadilla
  • Orchestrated technology and team members.
  • Introduced TDD.
  • Introduced clean code and guided workshops on the subject.
Technologies: Spring, Java

Senior Java Developer

2014 - 2016
Picadilla
  • Upgraded to Java version 8.
  • Improved the back-end system performance by a meaningful factor.
  • Made extensive use of Amazon Web Services to compile, package, and deliver our software.
Technologies: Spring, Java

Software Engineer

2013 - 2014
IBM
  • Involved in the architecture, development, and maintenance of high performance, distributed, transactional, and scalable security system which processes billions of security events per day.
  • Guided back-end guild workshops on cutting-edge software solutions.
  • Introduced a number of open-source solutions to common project problems.
Technologies: Spring, Java

Software Engineer

2011 - 2012
University of Heidelberg
  • Deployed an open-source, data-mining platform, and KNIME—for integrating, sharing and processing HCS data using a work-flow-oriented architecture.
  • Developed image processing (signal processing, automated segmentation, morphological operation, structure identification, filtering, classification), statistics, bioinformatics, and analysis methods.
  • Implemented data analysis including data modeling and visualization.
Technologies: KNIME, ImageJ, Java

Associate Software Engineer

2010 - 2012
ETH Zurich
  • Involved in designing and modeling data from life science—essentially large scale biological image and sequence data.
  • Worked at a university that was ranked #11 in the world's ranking ETH scores in computer science and #18 overall according to US News Education.
  • Wrote three publications on the subject.
Technologies: KNIME, ImageJ, Java

Senior Developer

2009 - 2011
Softisland Sp. z o.o.
  • Introduced the PHP Zend Framework to the company as an optimal web application development platform and Magento as the best eCommerce solution.
  • Led the development of a large-scale Magento solution that fits client's needs.
  • Developed a large amount of commercial and open extensions for Magento.
Technologies: Magento, Zend Framework, PHP

PHP Programmer

2008 - 2009
Planet Soft IT Outsourcing
  • Worked side by side as a PHP programmer—building various social networking services and websites.
  • Developed mostly with the Zend Framework and Symfony.
  • Designed, developed, tested, and documented web applications.
Technologies: Zend Framework, PHP

Professional Development and Training

• Magento Certified Front-end Developer
• Magento Certified Developer Plus
License: 5359963
https://u.magento.com/certification/directory/dev/77473

• Oracle Certified Expert, Java Persistence API Developer
• Oracle Certified Professional, Java Programmer
License: OC1104347

• Zend PHP 5.3 Certified Engineer
• Zend Framework Certified Engineer
• Zend Certified Engineer
License ZEND011643

Lackon.de

I built a Magento 2-backed shopping platform for the eBay giant, Lackon.de. Lackon.de focuses on companies in the automotive industry and offers workshop and paint shop supplies, car care, and cleaning products for detailing and accessories.

UrbanCity

A Magento shop for Polish clothing retailer in Germany.

Gavle GmbH

A shopping platform which I built together with over a dozen of extensions.

Sudoku Puzzle

Sudoku is a logic-based, combinatorial, number-placement puzzle. The objective is to fill a 9×9 grid with digits so that each column, each row, and each of the nine 3×3 sub-grids that compose the grid (also called "boxes," "blocks," "regions," or "sub-squares") contains all of the digits from 1 to 9.

This a version of Sudoku that I built.

Languages

Java, Kotlin, JavaScript, Go, PHP, Groovy, Java SE

Frameworks

JPA, Hibernate, Spring MVC, Spring Security, Spring Boot, Express.js, Spring, Zend Framework, Jakarta Server Pages (JSP)

Libraries/APIs

Node.js, React, jQuery, JPA 2

Tools

Git, Jenkins, GitLab, GitHub, ImageJ

Paradigms

Test-driven Development (TDD), Design Patterns

Platforms

JEE, Magento, Amazon Web Services (AWS), Linux, Android, Docker, Kubernetes, KNIME, Java EE

Storage

MySQL, Spring Data, MongoDB, PostgreSQL, Couchbase, Google Cloud, Spring Data JPA

Other

OCJP6, Software Development, Software Engineering, Software Architecture, Algorithms, Applied Mathematics, Multithreading

2008 - 2010

Master of Science Degree in Computer Science

Wroclaw University of Technology - Wrocław, Poland

2004 - 2008

Bachelor of Science Degree in Computer Science

The State Higher Vocational School in Nysa - Nysa, Poland

FEBRUARY 2018 - PRESENT

Magento Certified Front End Developer

Magento Commerce

JANUARY 2018 - PRESENT

Magento Certified Developer Plus

Magento Commerce

JULY 2014 - PRESENT

Oracle Certified Expert, Java Persistence API Developer

Oracle

APRIL 2012 - PRESENT

Oracle Certified Professional, Java Programmer

Oracle

JANUARY 2011 - PRESENT

Zend PHP 5.3 Certified Engineer

Zend Technologies

DECEMBER 2009 - PRESENT

Zend Framework Certified Engineer

Zend Technologies

AUGUST 2009 - PRESENT

Zend Certified Engineer

Zend Technologies

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.

1

Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.
2

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.
3

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