Roman Abakumov
Verified Expert in Engineering
Java Developer
Kiev, Ukraine
Toptal member since March 26, 2021
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
Experience
Availability
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
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.
Product Lead | Architect
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.
Senior Java Developer
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.
Senior Java Developer
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.
Product Lead | Senior Java Developer
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.
Experience
MyDHL Global Website
https://mydhl.express.dhl/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
Jive Cloud
https://www.jivesoftware.com/It supported a huge amount of integration to other collaborative systems.
ESG Data Collection and Transformation Software
Canadian Tire ECOM Platform
https://www.canadiantire.ca/I customized Hybris for the need of the customer to enable specific workflow and SKU management.
The Source Canada Initial Data Import
Education
Bachelor's Degree in Computer Science
Donetsk State Institute of Artificial Intelligence - Donetsk, Ukraine
Skills
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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