Roman Abakumov, Developer in Kiev, Ukraine
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Roman Abakumov

Verified Expert  in Engineering

Bio

Roman is a Java developer with 15 years of experience developing a range of Java projects, including pure back-end services, desktop apps, and asynchronous back-end services using the reactive Play framework. He is proficient with the Spring framework family, has relational database expertise, and can create unit and integration tests for the code he delivers. Roman's area of expertise is building new integrations to the external services using REST/SOAP protocols

Portfolio

An Online Freelance Agency
Java, Database, JavaScript, Spring Boot, MySQL, WebObjects, Project Lombok...
WorldTicket
Java, Spring Boot, JPA, RESTful Development, REST API, ETL, JDBC...
EPAM Systems
Play Framework, SBT, Liquibase, Spring Data, Reactive Programming...

Experience

Availability

Part-time

Preferred Environment

Linux, Windows, Git, Apache Maven, Gradle, Java

The most amazing...

...thing I've made was the MyDHL solution that's in use all over the world. I also led the build of an ESG data collection system that analyzes environmental data.

Work Experience

Java Chief Software Architect

2018 - 2021
An Online Freelance Agency
  • Invented the tooling to automate team processes, output quality which was integrated with several data sources like Jira, GitHub, Google Sheets, and an external database; resulted in increasing the overall ticket quality and PR delivered by the team.
  • Investigated and fixed issues reported by customers/QA team and covered them with the unit and integration tests.
  • Majorly refactored various products for the sake of code maintainability, performance, and readability. The scope of refactorings was to get rid of dead and duplicated code, memory leaks, and long methods/classes.
Technologies: Java, Database, JavaScript, Spring Boot, MySQL, WebObjects, Project Lombok, Spring Data, REST API, RESTful Development, Git, Spring, SQL, Apache Maven, PostgreSQL, Functional Programming, Hibernate, Unit Testing, Spring Security, Linux, Windows Development, Gradle, Ant Design, SOAP, HTML, Integration Testing, JSON, SQL Server, jQuery, CSS, NPM, Kubernetes, XML, Java, Jenkins, Back-end Developers, Web Development, AWS, REST, APIs, Java EE, Software Architecture, Debugging

Product Lead | Architect

2017 - 2018
WorldTicket
  • Gathered all the requirements and dependencies to implement the airline operations dashboard, choose appropriate technology stack, and identify integration points.
  • Implemented the app's back end and implemented ETL to gather and transform the single-tenant databases to multi-tenant and transform the data to reporting format. The app returns data in a REST format and uses OAuth for authentication purposes.
  • Implemented a simple HTML/JavaScript-based UI; jQuery was used to operate with a DOM and Ajax used to fetch the data from the back end.
Technologies: Java, Spring Boot, JPA, REST API, RESTful Development, ETL, JDBC, Project Lombok, Apache Maven, Mercurial, Keycloak, Spring, Database, SQL, Functional Programming, Unit Testing, Spring Security, Agile Development, JavaScript, Linux, Windows Development, HTML, Integration Testing, JSON, MySQL, SQL Server, jQuery, CSS, Oracle Development, Jenkins, Bitbucket, Full-stack, Back-end Developers, Web Development, REST, APIs, Java EE, Software Architecture, Debugging

Senior Java Developer

2015 - 2017
EPAM Systems
  • Added new frameworks to increase the application functionality and make it easier to maintain such as the Integrated Java JSR 303 validation API.
  • Solved multiple optimization tasks to minimize the memory usage and latency of responses and also prevent resource leaks.
  • Optimized the SBT/Play configuration to minimize UT run time, minimize CI time, and reduce the development cycle length.
Technologies: Play Framework, SBT, Liquibase, Spring Data, Reactive Programming, Oracle Database, SQL, Java, Git, Java, Spring, Database, RESTful Development, REST API, Functional Programming, Hibernate, Unit Testing, Spring Security, Agile Development, Project Lombok, JasperReports, Linux, Windows Development, Integration Testing, JSON, SQL Server, NPM, XML, Jenkins, Back-end Developers, Web Development, REST, APIs, Java EE, Software Architecture, Debugging

Senior Java Developer

2012 - 2015
EPAM Systems
  • Tailored eCommerce solutions to fit customer needs by developing all the missing functionality /extensions that were not provided out of the box.
  • Customized the build process to decrease build time by 4x without compromising on quality which helped to increase team output.
  • Led the team to resolve all the urgent client requests after production.
Technologies: Hybris, E-commerce marketing, Java, ImpEx, API Integration, Cockpit, Spring, SQL Server, MySQL, SOAP, REST, SQL, Git, Database, REST API, RESTful Development, Unit Testing, Spring Security, Agile Development, Project Lombok, JasperReports, Linux, Windows Development, Ant Design, Integration Testing, JSON, Java, Jenkins, Back-end Developers, Web Development, APIs, Java EE, Software Architecture, Debugging

Product Lead | Senior Java Developer

2006 - 2012
Ciklum
  • Designed and implemented a new data model invented by the client and successfully launched it to production on time.
  • Managed the team to deliver the needed features on time while also maintaining quality and performance.
  • Implemented an export process to transfer a huge amount of data in a limited-service window and automized it to minimize human interactions.
  • Designed a batch-processing framework on the server part to run heavy load operations sequentially, monitor its execution, and control its lifecycle.
  • Communicated with a client to gather the requirements, translate them into technical tasks, and provided estimations.
Technologies: Hibernate, PostgreSQL, XML, Java, JAXB, Ant Design, Apache Maven, Apache Wicket, RMI, jXLS, Big Data Architecture, SQL, Java, Spring, Database, Git, Unit Testing, Spring Security, Agile Development, JasperReports, Linux, Windows Development, SOAP, Integration Testing, SQL Server, Java, Back-end Developers, Web Development, APIs, Software Architecture, Debugging

MyDHL Global Website

https://mydhl.express.dhl/
A Play framework-based app which now in use all over the world to create and track shipments.

This application is highly customizable to be localized all over the world, including internationalization, and to follow all the rules and regulations in different countries about shipment processing.

Private users and organizations may use it, and even corporate users may build their own workflows around shipments.

This application was about to replace 13 legacy DHL portals and websites.

Airline Operational KPI Dashboard

This Spring Boot-based application gathers the data from multiple sources to the BI database and represents the most important information on the single screen. It uses ETL for data collection/transformation.

Jive Cloud

https://www.jivesoftware.com/
A Spring-based social networking app that is intended to be used for communication and collaboration solutions for business, including a suite of collaboration software and an intranet back end.

It supported a huge amount of integration to other collaborative systems.

ESG Data Collection and Transformation Software

The Spring-based software use Swing clients for data collection and complex workflows to transform, filter, and refine the data. The main users of this product were huge investment banks that use the data to refine their forecasts when making investments.

Canadian Tire ECOM Platform

https://www.canadiantire.ca/
An SAP Hybris ECOM solution developed for one of the biggest Canadian retailers.

I customized Hybris for the need of the customer to enable specific workflow and SKU management.

The Source Canada Initial Data Import

As part of the migration to the SAP Hybris, I handled the metadata and catalog import to the Hybris database from the old system. Later on, this data was used by the ECOM solution customized in further development.
1997 - 2002

Bachelor's Degree in Computer Science

Donetsk State Institute of Artificial Intelligence - Donetsk, Ukraine

Libraries/APIs

REST API, JasperReports, jQuery, JDBC, Liquibase, JAXB, jXLS

Tools

Git, Apache Maven, Java, Hybris, SBT, Bitbucket, Gradle, Mercurial, NPM, Pentaho Data Integration (Kettle), Keycloak, Jenkins

Languages

Java, SQL, XML, JavaScript, CSS, HTML

Frameworks

Spring, Hibernate, Spring Boot, Java, Ant Design, Play Framework, Spring Security, WebObjects, JPA, Apache Wicket

Paradigms

Agile Development, Functional Programming, Unit Testing, REST, RESTful Development, ETL, Reactive Programming

Platforms

Windows Development, Java EE, Oracle Database, Docker, Oracle Development, Linux, Kubernetes, AWS

Storage

Database, PostgreSQL, JSON, MySQL, Spring Data, SQL Server

Other

Integration Testing, Project Lombok, Back-end Developers, APIs, Software Architecture, Debugging, SOAP, Web Development, E-commerce marketing, ImpEx, API Integration, Cockpit, RMI, Big Data Architecture, Full-stack

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