Volodymyr

Volodymyr Milyukov
Senior Java Developer

SUMMARY

Seasoned Software Engineer with over 20 years of experience in Java, including enterprise
backend services, with a focus on the development and maintenance of complex, high-
reliability systems. Proven expertise in designing, developing, and supporting legacy and
modern enterprise solutions, integrating with RESTful backend services, and building
responsive desktop UIs for business-critical operations.

Hands-on experience working with peripheral devices, including printers, scanners, and
payment terminals, with a strong understanding of end-to-end workflows in POS and retail
environments. Skilled in Java, J2EE, Swing, EJB, Spring Boot/WebFlux, reactive
programming, multithreading, and distributed systems.

Proficient with Ant, Maven, IntelliJ IDEA, Eclipse, GitHub Actions, and Agile/Scrum practices.
Experienced in collaborating with cross-functional teams, participating in code reviews, and
mentoring peers to ensure high-quality, maintainable software.

KEY SKILLS

Programming Languages Java, JavaScript, TypeScript

AWT/Swing, JavaFX, GWT, JSP, Servlets, HTML/DHTML, CSS,
Desktop / UI Development
JS/jQuery, Spring Boot, Web Flux, JSTL

Spring Boot, Spring MVC, Spring WebFlow, Spring
Frameworks/Libraries WebFlux, Spring Security, Spring Data, EJB, JPA, Hibernate,
Stream Reactive, Struts, XWork
Database Tools / ORMs Oracle, MS SQL Server, PostgreSQL, JDBC, PL/SQL, noSQL.

IntelliJ IDEA, Eclipse, Postman, Oracle WebLogic, IIS,
Version Control & CI/CD
Windows, Linux, OS/2

Testing Tools JUnit, TestNG, Mockito, Cucumber, Automated GUI Testing

Agile Methodology Scrum, Kanban

Languages English - upper-intermediate; Ukrainian - native

EDUCATION
 Master’s Degree in Computer Science
State University 'Lviv Polytechnics'
2000

WORK EXPERIENCE
Java Backend Developer
Apr 2023 – Dec 2025

Project description:
A healthcare accessibility initiative delivering mobile laboratory services, offering convenient,
non-invasive medical screenings directly at clients’ homes or workplaces. The project utilized
advanced Point of Care technologies to provide timely and accurate diagnostics, reduce
healthcare costs, and enable early illness detection. Its primary goal was to make high-quality
healthcare more accessible while promoting proactive health management through
innovative, on-site screening solutions.

Key Contributions & Responsibilities:
 Designed and implemented core backend services using Spring Boot and Hexagonal
Architecture, ensuring clean separation between domains, application, and
infrastructure layers.
 Developed RESTful APIs for patient management, scheduling, authentication, and
medical process workflows.
 Integrated AWS S3 for secure medical document storage and SendGrid /Twilio for email
and SMS notifications.
 Implemented JWT-based authentication and token refresh mechanisms for secure
access control.
 Collaborated with the Front-End and DevOps teams to ensure consistent integration,
API documentation (via SpringDoc OpenAPI), and CI/CD delivery pipelines.
 Optimized database performance through query tuning and schema design
improvements.

Achievements:
 Successfully integrated AWS S3 presigned URLs, enhancing large file upload efficiency
and user experience.
 Played a key role in deploying a multi-region configuration system, allowing the app to
adapt dynamically based on regional settings.
 Contributed to the delivery of a production-ready, modular backend enabling faster
feature delivery and reduced maintenance complexity

Tech stack: Java 22, Spring Boot 3.5, Spring Security, JPA/Hibernate, PostgreSQL, Liquibase,
AWS S3, SendGrid, Twilio, Google Maps API, MapStruct, Maven, Docker.
__________

Java Backend Developer
Aug 2021 - Mar 2023

Project description:
A comprehensive web-based platform designed to empower small and medium-sized
businesses by centralizing key operations, including service management, communication,
supply chain, marketing, analytics, and third-party integrations—within a unified ecosystem.
The platform leveraged a modern microservice architecture and RESTful APIs to enable
 seamless interaction between internal modules and external services such as payment,
workflow, and e-commerce systems, streamlining business processes and improving
operational efficiency.

Key Contributions & Responsibilities:
 Developed and maintained microservice-based backend modules using Spring Boot,
following clean architecture and SOLID principles.
 Designed and optimized RESTful APIs for internal and external integrations (Stripe,
Monday.com, AWS, Amazon SP API).
 Implemented secure authentication and authorization using JWT and Spring Security,
including access/refresh token management.
 Managed database schema versioning and migrations via Liquibase, and optimized
PostgreSQL queries for performance.
 Integrated AWS S3 for file storage and implemented presigned URL access for media
assets.
 Automated API documentation with Springdoc OpenAPI and Swagger UI.
 Collaborated closely with frontend, DevOps, and QA teams to ensure seamless
deployment and high reliability.
 Maintained code quality and test coverage using Jacoco, Mockito, and JUnit
 Ensured compliance with Checkstyle.

Tech stack: Java 17, Spring Boot 2.7, Spring Data JPA, Spring Security, Liquibase, PostgreSQL,
AWS (S3, ECS), Stripe API, SendGrid, Monday.com, API, MapStruct, JWT, Swagger/OpenAPI,
Docker, Maven.
__________

Software Engineer
Nov 2019 - July 2021

Project description:
A large-scale content discovery platform serving billions of personalized recommendations to
users worldwide. The project focused on supporting and maintaining web supply systems for
the R&D team, ensuring platform stability, scalability, and high performance across a global
network of publisher sites.

Responsibilities:
 Developed and maintained one of the world’s largest real-time big data systems,
processing over 20TB of new data daily.
 Took end-to-end ownership of backend services — from design and development to
deployment, monitoring, and optimization.
 Collaborated closely with a highly skilled engineering team to deliver high-performance,
scalable solutions.
 Contributed to projects focused on Internet personalization, content feeds, real-time
bidding, and video recommendation systems.
 Played an active role in enhancing user engagement and shaping how billions of people
discover content online.

Tech stack: Java, Spark, Kafka, Hadoop, Cassandra, Vertica, MySQL, HDFS, BigQuery, Docker,
Linux.
__________
 Software Engineer
July 2019 - Nov 2019

Project description:
Involved in a large-scale enterprise project focused on supporting and maintaining SAP
Marketing solutions. The main goal of the project was to ensure system stability, implement
new features, and handle change requests to continuously enhance the functionality and
performance of the platform.

Responsibilities:
 Performed bug fixing and implemented new features to improve existing system
functionality.
 Handled change requests and ensured the timely delivery of updates and
enhancements.
 Participated in daily meetings and grooming sessions to align on priorities and technical
solutions.
 Collaborated closely with backend, frontend, UX, and QA team members to ensure
seamless integration and high-quality deliverables.
 Maintained and optimized backend services following clean code and reactive
programming principles.

Tech stack: Java 8, Spring Boot, Spring 5, Spring WebFlux, Spring Security, Stream Reactive,
Groovy, Cucumber, Microsoft SQL Server, IntelliJ IDEA, Postman, Jira, MS SQL Studio, Notepad+
+.

__________

Software Engineer
June 2018 - Nov 2019

Project description:
A leading clinical information system widely used in Danish hospitals, providing an integrated
clinical workplace for doctors, nurses, and medical staff. The system supports clinical, planning,
and patient administration tasks through a unified platform, improving hospital workflow
efficiency, ensuring coherent care pathways, and enhancing patient safety. The project also
included automated summarization and reporting tools for management decision-making.

Responsibilities:
 Developed software components to enhance system functionality and user experience.
 Designed and implemented automation tests to ensure software quality and reliability.
 Performed code refactoring to improve maintainability, performance, and adherence to
best practices.

Tech stack: Java 8, Swing, JUnit.
__________

Software Engineer
July 2017 - May 2018

Project description:
A single-entry platform enabling companies to interact with various Danish municipalities. The
platform integrates multiple data sources from municipalities, including message queues,
SFTP file transfers, and SOAP web service responses, to support diverse business scenarios. The
solution streamlines communication and data exchange between organizations and
municipal systems, providing a unified interface for end users.
 Responsibilities:
 Developed and maintained SOAP web services to handle multiple data exchange
scenarios.
 Implemented client-side functionality using Angular 5 and TypeScript for a responsive
and user-friendly interface.
 Ensured reliable integration with external systems, including message queues and SFTP
servers.
 Collaborated with the team to analyze requirements, troubleshoot issues, and optimize
service performance.

Tech stack: Java, SOAP Web Services, Angular 5, TypeScript.

__________

Software Engineer
April 2015 - June 2017

Project Description:
Developed a tax management platform for Danish companies, enabling both large and small
organizations to report tax returns efficiently. The platform provides a user-friendly interface
while ensuring compliance with tax laws, supporting interactions between companies,
consultants, and tax authorities. The system streamlines tax-related workflows and automates
key processes, improving accuracy and productivity.

Responsibilities:
 Implemented complex domain logic to support tax reporting and compliance
workflows.
 Developed backend services and web interfaces for seamless user interaction.
 Conducted code reviews and performed refactoring to improve maintainability and
performance.
 Wrote unit, integration, and automated GUI tests to ensure software quality.
 Fixed bugs and optimized system functionality to enhance stability and user experience.

Tech Stack: Java, JSP, JPA, EJB, JMS, Spring MVC, Spring Webflows, JS/jQuery, Maven, TestNG,
Mockito, GEB, Oracle WebLogic, Oracle Database, TeamCity.
__________

Software Engineer
Sep 2013 - Mar 2015

Project description:
A healthcare project for a Danish client aimed at supporting hospital nurses through a Java
desktop application. The system is part of a large, legacy enterprise solution designed to
enhance hospital workflows and help medical staff in their daily operations.

Responsibilities:
 Developed and maintained assigned modules within a legacy Java desktop application.
 Collaborated with a team of 8 developers to deliver high-quality, reliable software
components.
 Participated in Scrum ceremonies, including daily stand-ups, sprint planning, and
retrospectives.
 Ensured adherence to coding standards and best practices within assigned modules.

Tech Stack: Java 1.7, Swing, EJB, Oracle Database.
__________

Java Hardware Engineer
May 2011 - Aug 2013

Project description:
An embedded Java application to control LEDs, buttons, and sensors on Raspberry Pi using the
Pi4J library. Focused on real-time hardware interaction, digital input/output processing, and
device-level event monitoring.

Responsibilities:
 Developed embedded Java applications for Raspberry Pi hardware integration.
 Implemented GPIO pin control and hardware interfacing via Pi4J.
 Integrated sensors and actuators through I2C, SPI, and PWM protocols.
 Designed real-time event handling and digital I/O processing logic.
 Configured Linux (Raspberry Pi OS) environment for deployment.
 Set up Maven/Gradle build and deployment pipelines for ARM-based Java applications.

Tech stack: Java SE, Pi4J, Raspberry Pi OS (Linux), I2C, SPI, PWM, Maven, Gradle.
__________

Software Engineer
Sep 2009 - May 2011

Project description:
The implementation and support of a risk management system, providing tools to monitor
and manage risks across different business processes. The system included multi-platform and
multi-browser support, ensuring accessibility and reliability for users on Windows and Linux, as
well as in major browsers such as IE, Firefox, and Chrome.

Responsibilities:
 Developed and maintained UI components using GWT and AWT/Swing.
 Implemented features based on detailed specifications and business requirements.
 Conducted code reviews and evaluations to ensure software quality and maintainability.
 Provided ongoing support for multi-platform and multi-browser compatibility.

Tech Stack: Java, GWT, AWT/Swing, Windows, Linux, IE, Firefox, Chrome

Intermediate to Advanced Skills:
 Strong proficiency in Java Swing and AWT for building desktop GUI applications.
 Hands-on experience with key Swing components: JFrame, JPanel, JButton, JLabel,
JTable, JTree, JList, etc.
 Solid understanding of AWT components: Frame, Panel, Button, Label, TextField,
Checkbox, Choice, etc.
 Expertise in Layout Management for both Swing and AWT: FlowLayout, BorderLayout,
GridLayout, CardLayout, BoxLayout.
 Skilled in Event Handling using the Delegation Event Model (ActionListener,
MouseListener, KeyListener, etc.).
 Knowledge of MVC architecture and its application in GUI design.
 Table & Tree Models – Customizing TableModel, TreeModel, and using
DefaultTableModel.
 Data Binding – Binding Swing components to data models.
 Drag and Drop (DnD) – Implementing DnD with TransferHandler.
 Focus & Keyboard Management – FocusTraversalPolicy, Key Bindings vs KeyListeners.
  Internationalization (i18n) – Supporting multiple locales.

Core GUI Programming (AWT/Swing):
 Custom UI design by extending JComponent and overriding paint() / paintComponent().
 Implementing and customizing Look and Feel (LAF) in Swing applications.
 Managing menus, toolbars, dialogs, and context menus (JMenuBar, JDialog,
JOptionPane, etc.).
 Graphics programming with AWT Graphics & Graphics2D API - drawing shapes, images,
and custom rendering.
 Handling images, icons, and fonts efficiently in GUI design.
__________

Software Engineer
Feb 2008 - April 2009

Project Description:
Development and management of an enterprise web application designed to deliver robust
and compliant solutions by integrating backend services with dynamic, user-friendly web
interfaces, enabling efficient and reliable business operations.

Responsibilities:
 Analyzed requirements and prepared high-level design and implementation guidelines.
 Developed features according to specifications using backend and frontend
technologies.
 Implemented UI components with CSS, JavaScript, and FreeMarker templates.
 Conducted code reviews and evaluations to ensure compliance with project
requirements.
 Performed integration and merging of source code into the production environment.
 Managed project planning, configuration, and quality assurance processes.

Tech Stack: Java, JDBC, Hibernate, JSP, Servlets, Spring WebFlow, FreeMarker, HTML/DHTML,
JavaScript, AJAX, CSS, XML/XSLT, Tomcat, MS SQL Server 2000, Ant, Ivy, SVN
__________

Software Developer
Sep 2007 - Feb 2008

Project description:
A system for exporting and importing data across multiple platforms, featuring custom plugins
for Atlassian Jira and Confluence. The platform streamlined HR data management and
improved operational efficiency through seamless integration and automation of key
processes.

Responsibilities:
 Designed and implemented plugins for Jira and Confluence to extend platform
functionality.
 Developed backend services for data import/export using Java Servlets and XML
technologies.
  Utilized XPATH, XSLT, Velocity, and XWork for data transformation and workflow
implementation.
 Ensured integration with Jira API and maintained reliable communication between
systems.
 Gained deep expertise in Atlassian platforms and enterprise plugin development.

Tech Stack: Java Servlets, XML, XPATH, XSLT, Velocity, XWork, Jira API.
__________

Software Developer
Feb 2002 - Jul 2007

Worked on a variety of enterprise and corporate projects, including web applications, client-
server modules, and internal business systems. Developed solutions involving Active Directory
integration, XSL utilities, web scraping tools, and CMS/billing platforms. Contributed to both
frontend and backend development, implementing features, maintaining existing systems,
and ensuring application stability.

Tech Stack: Java, Java Servlets, JSP, Struts, HTML, AJAX, JavaScript, XML, XSLT, Velocity,
XWork, VBA, ASP, Access, Databases, IIS, JSTL, TLB.
__________

Programmer-Engineer
Jan 2000 - Apr 2002

Worked on client-server software development, database administration (Oracle, MS SQL,
Interbase), and IT support for laboratory environments. Managed local networks, provided
hardware and software support, and trained staff.

Tech Stack: Delphi, FoxPro, Oracle, SQL Server, VBA.