Paul Lysak

Kharkiv, Ukraine

Member since July 28, 2014

Paul is an experienced developer with a main focus on server side Scala/Java. Lately, he has striven to use modern reactive approaches to building reliable and resource-efficient applications. He values and promotes robust systems through his work with in-depth protection and maintainable code with clear logical separation. Paul seeks to understand and address the root of the problem, rather than simply find quick fixes.

Paul is now available for hire

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Portfolio

Sentrana, Inc. (via Toptal)
Scala, Play, MongoDB, Spark, Redshift
Kreditech
Scala, Java, Spring, Hibernate, Maven, PostgreSQL, RabbitMQ, MongoDB
JasperSoft
Java, Maven, Hibernate, Spring, JavaScript, jQuery

Experience

Java, 9 years
Object-oriented Programming (OOP), 7 years
SQL, 7 years
Scala, 3 years
Functional Programming, 2 years
Play, 2 years
Spark Core, 1 year

Availability

Part-time

Preferred Environment

Linux, IntelliJ IDEA, Git

The most amazing...

...thing I've created is SQL query parser with Scala parser combinators. It was ready to do useful stuff in just two days.

Employment

Scala Developer
Sentrana, Inc. (via Toptal)
2016 - 2017
- Implemented the core of the back-end for data transformation workflow.
- Created a fully reactive user management service and SDK for simple integration into other projects.
- Led the development of an opportunity analysis system, from early proof of concept to minimum viable product.
Technologies: Scala, Play, MongoDB, Spark, Redshift
Scala Developer
Kreditech
2013 - 2015
- Developed an online loan processing application core.
- Handled investigation and troubleshooting of production issues.
- Improved system transparency by setting up collection of log metrics and developing an audit trail sub-system.
- Developed infrastructure for indexing data in Elasticsearch in order to improve scalability and convenience of use.
- Tuned RabbitMQ queues to ensure that no incoming payments are lost and that system performance is fine.
Technologies: Scala, Java, Spring, Hibernate, Maven, PostgreSQL, RabbitMQ, MongoDB
Java/JavaScript Developer
JasperSoft
2011 - 2013
- Handled bug fixes and improvements in Jasper Reports Server.
- Researched the possibility of integrating JavaScript asynchronous modules (AMD) into an existing system. Contributed to some open source tools, for example https://github.com/ibolmo/jasmine-jstd-adapter/pull/18.
- Developed UI for a federated data source configuration so that multiple databases would look like one large database.
Technologies: Java, Maven, Hibernate, Spring, JavaScript, jQuery
Java Developer
Team International
2010 - 2011
- Ported parts of a middleware layer of a telecom system from WebLogic to JBoss.
- Handled bug fixes and improvements for a media content management system.
Technologies: Java, Spring, Hibernate, Maven, JBoss (ESB, jBPM), EJB3
Java Developer
Grid Dynamics
2010 - 2010
- Extended an application for in-memory data grid testing.
- Developed a data normalization layer for a web crawler.
Technologies: Java, Spring, Hibernate, Lucene, GWT, JavaScript, jQuery, Ruby
Java/JavaScript Developer
Freelance
2009 - 2010
- Developed parts of a web application for drawing sketches and ordering engravings.
Technologies: Java, Spring, Hibernate, DWR, Batik, Maven, JavaScript, jQuery
Java Developer
Uniquare
2007 - 2008
- Developed a bank teller workplace automation application.
Technologies: Java, Ant, JavaScript

Experience

ETL tool for personal finance tracking (Development)
https://github.com/paul-lysak/finloader
A tool that parses raw data stored in CSV files, transforms it, and saves it into a relational database for further analysis. I use it for my finance tracking.
CSV streaming parser (Development)
https://github.com/paul-lysak/CsvStreamingParser
A JavaScript library for parsing large CSV files piece-by-piece.

Skills

Languages
Java, Scala, SQL, JavaScript
Frameworks
Spring, Akka, Play, Mockito, Hibernate, TestNG, Finagle, JUnit
Tools
Git, Spark SQL, SBT, Maven, RabbitMQ, ScalaTest
Paradigms
Object-oriented Programming (OOP), Functional Programming, Object-oriented Design (OOD)
Platforms
Spark Core, Linux, Heroku
Libraries/APIs
spray, ScalikeJDBC, jQuery, Slick
Storage
MongoDB, PostgreSQL
Misc
AWS EMR, Elasticsearch, AWS S3

Education

Master's degree in Applied Mathematics
Kharkiv Polytechnical Institute - Kharkiv, Ukraine
2003 - 2009

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