Leading the research, design, development, documentation, testing and rollout of fuel card payment applications.● Managed, hired and mentored 4 new teams with a total of 15 Software developers and 6 QAs for the new Core Systems Transformation program to deliver in time the following key services for the program: - New Site (gas station) locator service. - New Real-time billing service. - Payment card Tokenization service. - Custom Authorization ETL service to provide near real time replication between several back-office systems and a fuel card authorization server.● All delivered services above use a highly available and scalable architecture and are deployed in Amazon Web Services (Lambda / Elastic Container Service) and Red Hat OpenShift / Kubernetes clusters.● Drove all phases of enterprise integration and process improvement projects to successful completion, including application availability initiatives (e.g., microservices-based architecture, clustering, data replication etc.) and the implementation of fail-over and disaster recovery options.● Reduced R&D budget by 30% while increasing service levels and improving product stability.● Technologies: Java, Spring Boot, Spring Batch, Hibernate framework, Maven, JUnit, Mockito, Cucumber, OpenAPI / Swagger / GraphQL, Event-driven architecture (AWS Lambda, AWS Step Functions, Kafka, AWS SQS, Spring Cloud Stream), CI/CD (Kubernetes, AWS ECS, Gitlab pipelines, Ansible Tower, Terraform, SonarQube), Databases (PostgreSQL, MySQL, Oracle), NoSQL databases (Amazon DynamoDB, Amazon DynamoDB Streams, Amazon DynamoDB Accelerator – DAX, Redis).

Architected and delivered the Real-time Tax calculation service. The service allowed business to expand customer portfolio for the tax-exempt customers.● Managed, hired and mentored 1 new team with a total of 4 developers and 2 QAs.● Technologies: Java, Spring Boot, Spring Batch, Hibernate framework, Maven, JUnit, Mockito, Cucumber, OpenAPI / Swagger / GraphQL, Event-driven architecture (AWS Lambda, AWS Step Functions, Kafka, AWS SQS, Spring Cloud Stream), CI/CD (Kubernetes, AWS ECS, Gitlab pipelines, Ansible Tower, Terraform, SonarQube), Databases (PostgreSQL, MySQL, Oracle), NoSQL databases (Amazon DynamoDB, Amazon DynamoDB Streams, Amazon DynamoDB Accelerator – DAX, Redis).

Lead the research, design, development, documentation, testing and rollout of bank payment applications.● Managed, hired and mentored a development team in Agile SDLC best practices (total of 4 developers).● Designed and delivered several new services for automatic wire / EFT transfer and reconciliation with major banks and third-party payment processors, which allowed to onboard several key customers (>30% of the total transaction volume) and cut down operational costs. ● Optimized and enriched wire validation process to facilitate faster payment processing and reduce possibility of chargebacks.● Technologies: C#, ASP.NET MVC, Entity Framework, LINQ, Microsoft SQL Server (TSQL / Stored procedures), XML, Web and Windows services, WCF SOAP and REST API services, Hangfire framework (background jobs and workers), event driven architecture using NserviceBus and RabbitMQ, Visual Studio Code, JavaScript / TypeScript, CSS / HTML, React, Jira, Git (Bitbucket), xUnit, SonarQube, REST, SOAP, ISO 20022, JSON, XML, Postman, Swagger

Major payment system re-engineering and documentation to improve stability and performance by using message-based architecture and microservices. Getting the system ready for SOX compliance certification.Duties & Responsibilities:● Business requirements’ gathering and documentation, performing the gap analysis of the system modules.● Collecting Technical requirements’, preparing their specification and reconciling with the project management office (PMO), project owners and external customers.● Legacy system databases re-engineering and documenting.● Object oriented design and source code development according to technical specifications of transaction processing system modules with the use of:● C#, ASP.NET MVC4, Entity Framework, LINQ, Microsoft SQL Server (TSQL / Stored procedures), XML, Web and Windows services, HangFire (background jobs and workers), NServiceBus, RabbitMQ, Visual Studio Code, JavaScript/TypeScript, CSS/HTML, React, Jira (Scrum methodology), Git (Bitbucket), unit testing with xUnit, REST/SOAP, ISO 20022, JSON/XML, PostMan, Swagger

Advanced through several promotions, culminating in head of department role, overseeing company’s software development activities in a field of fuel card processing and loyalty programs.● Designed and implemented various payment, loyalty and gift card solutions, driving continuous improvement to processes, systems, workflow and customer satisfaction.● Developed and delivered new fuel card online transaction processing system characterized by fault tolerant 'active-active' clustering and 'host-to-host' transaction routing using proprietary and ISO 8583 H2H protocols including firmware for the EFT POS terminals (Ingenico platform).● Designed and delivered a new version of back-office platform, which was used for transaction processing, clearing, reporting and fuel / loyalty card management.● "Universal fuel card" (UC) platform development enabling integration of co-brand B2B and B2C fuel payment cards with major banks in Eastern Europe. Java Card applet development for fuel card acceptance on bank EFT POS terminals in EMV mode.● Developed and delivered a Lottery ticket online sale system with a web portal for the account and distribution management of paper lottery tickets.● PetrolPlus system security improvement with Thales payShield HSM modules and Citrix SSL accelerators. PA DSS and PCI DSS certification of PetrolPlus system components.● Technologies: Java (Spring Boot, Hibernate framework, Maven, JUnit, Mockito, OpenAPI / Swagger / GraphQL), event-driven architecture (Kafka), C++ (STL, Boost, multithreading, WinSock, ACE framework and Proactor pattern), CI/CD (GitLab / Jenkins / Octopus / SonarQube), Databases (Oracle, PostgreSQL, Microsoft SQL Server), NoSQL databases (Redis), Multithreading, Smartcards, Contactless, Mifare, NFC, EMV, GlobalPlatform, Cryptographic algorithms, HSM

Object oriented design and implementation of transaction payment processing systems:● Design and development of various applications for EFTPOS terminals (Ingenico and Gemalto platforms)● Design and development of various applications for Windows platform (communication server, terminal management server etc)Programming languages: C/C++, Assembler (x86)Tools & technologies: STL, Boost, Borland C++ Builder, Microsoft Visual Studio, GNU C/C++, Intel Integrated Performance Primitives (IPP), Intel VTune, Win32 API, TCP/IP (WinSock and ACE framework), COMOther: UML, XML, Multithreading, Regular Expressions, Smartcards, NFC, Cryptographic algorithmsTeam leadership responsibilities:● Team leading and project managing● Professional developers’ team hiring and training

Object oriented design and implementation for the payment transaction processing system modules. Selected projects:● Design and development of differential file transfer and data compression module, aimed on accelerating the exchange between EFTPOS terminal and communication server and reducing traffic costs ● Design and development of executable overlay linking and loading module aimed on overcoming memory limitations of 16 bit EFTPOS platform (Gemalto)

Developing new version of telemetry data transmission and processing system.Duties and responsibilities:● Business requirements gathering and documentation, gap analysis for new version of telemetry data processing system● Collecting business requirements’, preparing their specification and reconciling with the project owners. Performing cost-benefit analysis and cost optimization for hardware and software components● Performing system and database design using CA BPwin / ERwin● Developing core components source code according to technical specifications for data collection, pre-processing, storage and visualization modules using Borland C++ Builder and VCL library● Conducting testing, debugging, bug fixing and performance tuning using NuMega BoundsChecker for Borland C++● Implementing database core with Firebird database server, SQL, stored procedures, external functions (UDF)● Maintaining source code with static code analyzers and version control system such as Lint, Microsoft Visual SourceSafe● Conducting source code reviews and training other team members● Preparing Technical and the End User documentation and its maintenance● The 3rd line support for system’s users providing. Performing system installation on customer premises for pilot projects

Design and development of pricing and warehouse modules. Development and customization of accounting and HR management modules. Microsoft SQL Server administration.Duties and responsibilities:● Business requirements’ gathering and documenting. Requirements’ collection, technical requirements’ specification writing and reconciliation with the project owners● Database design using CA ERwin● Object oriented design and source code development according to requirements specifications using 1C Enterprise system scripting language and Microsoft SQL Server T-SQL stored procedures● Object oriented design and source code development according to requirements specifications using Borland C++ Builder and Borland Delphi for trade equipment integration into warehouse system (POS system, weighing equipment, bar code printers / scanners, etc.)● Testing, debugging, fixing errors in source code using Bugzilla as a bug tracking system● Applications performance optimization● Maintained source code with VSS version control system● Technical and end user documentation writing and maintenance● Evaluation and cost optimization of software and hardware components● Microsoft SQL Server administration: - Designing and implementing database backup/restore and disaster recovery strategy - Database logical and physical optimizing● System’s end users support