Junior Java Developer with hands-on experience building backend services using Java, Spring Boot, REST APIs, and relational databases. I have worked closely with a senior mentor on real-world projects, including a full-stack Tic-Tac-Toe application with authentication, AI integration, and microservices architecture using Kafka and Docker. I bring a strong analytical mindset from my previous scientific background and a practical, problem-solving approach to software development.

Sylwia Barteczko

Junior Java Developer with hands-on experience building backend services using Java, Spring Boot, REST APIs, and relational databases. I have worked closely with a senior mentor on real-world projects, including a full-stack Tic-Tac-Toe application with authentication, AI integration, and microservices architecture using Kafka and Docker. I bring a strong analytical mindset from my previous scientific background and a practical, problem-solving approach to software development.

Available to hire

Junior Java Developer with hands-on experience building backend services using Java, Spring Boot, REST APIs, and relational databases. I have worked closely with a senior mentor on real-world projects, including a full-stack Tic-Tac-Toe application with authentication, AI integration, and microservices architecture using Kafka and Docker. I bring a strong analytical mindset from my previous scientific background and a practical, problem-solving approach to software development.

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Experience Level

Expert
Expert
Expert
Expert
Expert
Expert
Intermediate
Intermediate
Intermediate
Intermediate
Beginner
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Language

Javanese
Advanced

Work Experience

Junior Java Developer (Mentored Real-World Projects) at Java Development Mentorship Program
September 1, 2023 - Present
Learned backend development through a 1:1 mentorship with a senior developer, applying real-world workflows and best practices. Developed backend applications using Java, Spring Boot, Hibernate, and PostgreSQL, following clean architecture and SOLID principles. Built full-stack web applications using Thymeleaf, HTML, CSS, and JavaScript, integrating REST APIs and secure login with Spring Security and JWT. Managed relational databases and wrote optimized queries. Wrote unit and integration tests with JUnit and Testcontainers; used Git and Docker for versioning and deployment. Practiced team-like development with code reviews, refactoring, and collaborative workflows.
Quality Assurance Technician at Marios's Gelati
June 30, 2023 - July 15, 2025
Led the Quality Assurance department, ensuring compliance with CFIA, HACCP, and GMP standards. Managed and optimized quality control processes, implementing automation where possible. Conducted data analysis and reporting, improving production efficiency and product consistency. Supervised and trained production workers, ensuring adherence to quality protocols. Coordinated third-party audits and governmental inspections, maintaining regulatory compliance.
Technologist at Marma SP Z O.O.
December 31, 2021 - July 15, 2025
Managed process optimization and supervised laboratory testing. Implemented new raw materials and technologies, improving production quality. Maintained and updated technical documentation for process validation.
Quality Assurance at Danone S.A.
August 31, 2021 - July 15, 2025
Managed quality assurance and compliance with GHP, GMP standards. Led data analysis and process optimization projects to improve efficiency. Collaborated on cross-functional initiatives to enhance production quality. Maintained technical documentation and provided team training.
Quality Control Assistant at Greencore, UK
August 31, 2016 - July 15, 2025
Conducted quality control checks in a fast-paced production environment. Collected and analyzed production data, ensuring compliance with quality standards. Reported findings and assisted in process optimization to improve efficiency.
Order Management Associate at Morrison, UK
August 31, 2015 - July 15, 2025
Managed order processing and fulfillment, ensuring accurate inventory tracking. Optimized workflow efficiency, reducing errors in shipment preparation. Developed strong attention to detail and problem-solving skills in a high-pressure environment.
Quality Assurance at Danone S.A.
August 1, 2021 - August 23, 2025
Managed quality assurance and compliance with GHP and GMP standards. Led data analysis and process optimization projects to improve efficiency. Collaborated on cross-functional initiatives to enhance product quality. Maintained technical documentation and provided team training. Managed process optimization and supervised laboratory testing.
Quality Control Assistant / Quality Assurance Technician at Marma SP Z O.O.
December 1, 2021 - August 23, 2025
Implemented new raw materials and technologies to improve production quality. Maintained and updated technical documentation for process validation. Conducted quality control checks in a fast-paced production environment. Collected and analyzed production data ensuring compliance with quality standards. Reported findings and assisted in process optimization to increase efficiency.
Order Management Associate at Mario’s Gelati
June 1, 2023 - August 23, 2025
Managed order processing and fulfillment, ensuring accurate inventory tracking. Optimized workflow efficiency, reducing errors in shipment preparation. Developed strong attention to detail and problem-solving skills in a high-pressure environment.
Junior Java Developer (Mentored Real-World Projects) at Java Development Mentorship Program
September 1, 2023 - Present
Learned back-end development through structured 1:1 mentorship with a senior developer, applying real-world workflows and best practices. Developed back-end applications using Java, Spring Boot, Hibernate, and PostgreSQL, following clean architecture and SOLID principles. Built full-stack web applications using Thymeleaf, HTML, CSS, and JavaScript, integrating REST APIs and secure login with Spring Security and JWT. Managed relational databases (PostgreSQL, MySQL, SQLite) and wrote optimized queries. Wrote unit and integration tests with JUnit and Testcontainers; used Git and Docker for versioning and deployment. Practiced team-like development with code reviews, refactoring, and collaborative workflows.
Quality Control Assistant at Greencore, UK
August 1, 2016 - August 23, 2025
at Morrison, UK
August 1, 2015 - August 23, 2025
Junior Java Developer at Java Development Mentorship Program
September 20, 2023 - October 28, 2025
Mentored real-world projects; backend development using Java, Spring Boot, and Docker; applied best practices in software development, including test-driven development, version control, and clean architecture.
Quality Assurance / QA Analyst at Danone S.A.
August 1, 2021 - August 1, 2021
Led data analysis and process optimization projects to improve efficiency; contributed to quality assurance activities and cross-functional collaboration to enhance product quality.
Junior Java Developer at Java Developer Mentorship Program
September 20, 2023 - Present
Managed quality assurance and compliance with GMP standards. Led data analysis and process optimization projects to improve efficiency. Collected and analyzed production data, ensuring compliance with quality standards. Reported findings and assisted in process optimization to improve efficiency. Managed order processing and fulfillment, ensuring accurate inventory tracking. Optimized workflow efficiency, reducing errors in shipment preparation. Led the Quality Assurance department, ensuring data consistency and process reliability by validating outputs and maintaining structured processes. Analyzed and validated test results, ensuring data accuracy, consistency, and traceability. Supervised and trained production workers, ensuring adherence to quality protocols. Coordinated third-party audits and governmental inspections, ensuring end-to-end process compliance.

Education

Master of Science at University of Silesia, Poland
January 1, 2015 - December 31, 2020
Master of Science at University of Silesia, Poland
January 1, 2015 - January 1, 2020
Master of Science at University of Silesia, Poland
January 1, 2015 - January 1, 2020
Master of Science in Biotechnology at University of Silesia, Poland
January 1, 2015 - December 31, 2020

Qualifications

Java Development Mentorship Program
September 1, 2023 - July 15, 2025

Industry Experience

Software & Internet, Life Sciences, Manufacturing, Consumer Goods, Wholesale & Distribution, Healthcare, Professional Services