Java Software Engineer Portfolio

2021-2023 Datastream Service

Contributed to the design of data stream product for seamless data copying to OLAP and data lakes. The system taps into RDBMS CDC and publishes reconstructed entities to a Kafka-based messaging bus. I had full responsibility of the object materialization using Salesforce Partner API.

Used technologies:

• Java, Avro;
• Salesforce Partner API;
• PostgreSQL/SDB.

2018-2020 DB Comparator Service

Designed and led development of database comparator that finds and reports any data discrepancies between heterogeneous data stores. It scaled extremely well to compare databases with terabytes of data. Wrapped in Sprint Boot and CLI.

Used technologies:

• Java, Spring Boot, REST, CLI;
• Oracle, PostgreSQL, MySQL.

2018-2021 Consistent DB Copy Service

Used technologies:

• Java, JDBC, Change Data Capture (CDC), Avro, JWT;
• Oracle, PostgreSQL/SDB, MySQL;
• TLS/mTLS, Hashicorp Vault Integration.

2017-2019 Static Database Copy Tool

Contributed to a highly scalable heterogeneous database cloning tool that could copy all or subset of data between various relational databases. I was responsible for the abstraction layer between the logic and RDBMS support including SQL optimizations and data conflict resolutions.

Used technologies:

• Java, JDBC, Avro;
• Oracle, PostgreSQL, MySQL, Microsoft SQL Server;

2014-2016 Project: VMware vRealize Automation (vRA)

Designed, prototyped and implemented extensibility modules to support various use cases. Also worked on design and implementation of reports and dashboards.

Significantly improved database performance of the catalog and deployment related vRA functionality. Analyzed hundreds of SQL statements and arranged a set of indexes to balance SQL performance and index maintenance overhead in PostgreSQL. Optimized slow SQL queries to run up to 20 times faster on a large data set.

2012-2014 Project: VMware Application Services (aka Application Director)

Worked on multiple features of VMware Application Services (AppD). Extended database and back-end. Extended ORM/service layers, and command line interface. Was responsible for design and implementation of the Application Services public REST API.

Used technologies:

• Java, Spring Framework, REST;

2008-2010 Project: DevOps Reports and Dashboard

I designed and implemented hundreds of the DevOps reports to support the team processes.Designed and built a DevOps Dashboard that was quickly recognized as extremely helpful by both engineering and management. Prototyped and implemented the company-wide reporting solution.

Used technologies:

• Microsoft SQL Server Reporting Services (SSRS);
• .NET (C#/C Sharp, ADO.NET);
• Oracle, MS SQL Server, MySQL, PostgreSQL.

2007-2011 Projects: VMware LabManager and vCloud Director

Converted vCloud Director database to Oracle and PostgreSQL. SQL performance optimizations. Designed and implemented modules, frameworks, and components using Java.

Used technologies:

• Java, C#, Perl; Spring Framework, Hibernate;
• GoF patterns, architectural patterns;
• MS SQL Server, PostgreSQL, MySQL, Oracle 10g/11g trigger and stored procedure development;
• MS SQL Server Reporting Services.

2006 Project: Hardware Tracing Within The Company

Using .NET C# I developed the Business Logic, Persistence and Presentation application layers. I developed database schema and stored procedures to specify and meet all security requirements for the application. A background thread is used regularly to detect if the data on the server has been modified.

Used technologies:

• MS .NET (C#/C Sharp, ADO.NET, Generics, Threading, Data Binding with WinForms, Reflection);
• Model-View-Controller pattern, GoF patterns (Factory, Singelton, Flyweight, Proxy and other patterns);
• Oracle 9i trigger and stored procedure development, PL/SQL Developer, TOAD;
• NUnit, SourceSafe.

2006 Project: Telephone Directory for Local Telephone Network

Used technologies:

• ASP.NET, C#, ADO.NET, Generics, Data Binding with WebForms controls;* MS SQL Server 2000 under the XML Web Service;
• Used Caching multiple versions of a page strategy depending on the value of the search parameters;
• Used Master pages for the future easy maintenance.

2005 Project: .NET Database Component Service Tool

I developed a component which can be used for database driven application development to utilize its functions such as user identification, transaction support and multi-threaded access to database. This component can be used with Oracle, MS SQL Server and Access databases. It also has built-in interfaces for working with other databases.

Used technologies:

• C#, WinForms, .NET Reflection;
• Design patterns (Command, Façade, Template Method, Observer);
• Test driven development, NUnit;
• WinForms Internationalization/localization.

2005 Project: Billing system for the local telephone network

I developed an application for systematizing the telephone billing data collected from Iskratel SI2000 telephone routers. The challenge was to test and tune the application’s performance on a database with millions of records.

Used technologies:

• Borland Delphi, Oracle 8i/9i;
• Design patterns: Strategy, Template Method;
• Regular expressions to parse text billing data, text file code page auto detection.

2004-2005 Project: Regulative Workforce Calculation

I developed the workforce calculation method for the Standard Research Laboratory at The Labor Environment Institute. I have had complete responsibility for conceptualization, data modeling, coding, testing, and algorithms design for the personnel bank resources calculation. As a part of the application I developed 35 complex auto-generated reports that show different aspects of workforce calculation data in MS Excel format and help workforce engineers to analyze this data.

Used technologies:

• Borland Delphi, Oracle 9i, VCL development, Design Patterns, third party components, DevExpress;
• COM/OLE for custom report development in MS Excel and MS Word;
• Synchronization of the multiple databases placed in remote affiliations of our company;
• XML, XSLT for integration with other workforce systems.

2003 Project: Corporate Web Site

I used web programming and database development skills for producing corporate intranet site. I implemented the authorization and supervision functions for the site administrators which allowed them to use web interface for revising the content and reviewing site statistics. Also using JavaScript I implemented and tested in different browsers multi-layered popup menu.

Used technologies:

• Server side programming: Active Server Pages (ASP), ADO, Oracle, MS Access, IIS;
• Client side programming: cross-browser JavaScript, VBScript, HTML, CSS.

2001-2003 Project: Workplace Attestation

Client-server application with Windows “rich client” that used SQL-92 standard to access the database, so Oracle, MS SQL Server or local database could be used as a back-end database. I developed this application to help The Standard Research Laboratory at The Labor Environment Institute with workplace attestation. Workplace Attestation estimates the workforce ratio to the amount of work that should be done in a specified time.

Used technologies:

• Borland Delphi 5, SQL, Oracle 8i/7.3, Paradox, OLE for MS Excel reporting;
• Design patterns: Table Data Gateway, Template Method, Factory.