* Designed and implemented several core functionality features - distributed transaction engine, integrated with payment providers (SEPA, Stripe), implemented corporate business clients, payment limits, tariffs etc.* Worked tightly with BA, CTO, PO and UX on implementation of new functionality. * Fixed bugs, improved DB access performance more than 2 times, monitored errors using ArgoCD, Sentry, AWS CloudWatch and raised incidents, carried out feature initial assessments.* Technology stack: event-driver moduled distributed monolith, Java 11, Docker, jOOq, Postgres, ActiveMQ, Redis, AWS

* Led the transformation of a single-node technical infrastructure into an auto-scaling resilient multi-node cluster with caching hot data, extending its availability across multiple countries and serving 10 times more requests.* Designed and directed development of new business functionality and integrations with payment systems (stripe, wise), google api, elasticsearch, aws services, invoicing, working with emails, sms, and many others.* Interviewed 60+ technical candidates, mentored and guided two interns, facilitated their transition to junior developer position through hands-on training and ongoing support.* Closely worked with all stakeholders - BA, CTO, PM and R&D* Tools&Technoligies: Java 11, Spring (Boot, Security, Mongo), Maven, MongoDB, REST, AWS, AWS API, GoogleAPI, Stripe, invoicing APIs, ELK, Redis, Microservices, Selenium, REST

* Took part in sprint planning, coding features, bug fixing;* Worked on long performance improvement that decreased single user request time from 10 ms to 4 ms which increased average throughput by 250%.* Done release management comprising of multi-phase deployment on cluster node subsets;* Tools&Technoligies: Java 17, Microservices, Spring (Boot, Cloud, Security, WebFlux, Data), Hibernate, MySql, RabbitMQ, Apache Kafka, Camel, Netty, Protobuf, Junit5, Spock, Maven, AOP, REST

* Introduction into:Programming, Web, Client-server interactionJava syntax, semantics, classes, methodsOOP, data structures, algorithms* Supervised students, revised home works

* Done integrations with SOAP and REST, endurance tests and wrote bash scripts for Windows and Linux OS* Designed and implemented new payment system for withdrawal and deposit customer money* Played roled of a scrum master on periodical basis - preparing next release scope, coding features, bug fixing; Providing periodical releases* Tools&Technoligies: JavaEE, Java 11, REST, Microservices, Spring Boot, Hibernate, MyBatis, OracleDB, RabbitMQ, SOA, Junit4, Maven, TestNG, Gitlab CI/CD, Docker

The product allows IT departments through a single administration dashboard to aggregate, manage, deliver, and track hardware, software, and services from multiple cloud-based and on-premises sources.* Created GDPR solution feature for the whole project to comply with European user data management requirements.* Designed and implemented several functionality-reach features.* Involved in architecture revising of microservices and their interoperability* Tools&Technoligies: Java 8, Spring (Boot, Security, Batch, etc) Hibernate, OracleDB, MySql, Kafka, Junit4, Spock, Mockito, Maven, Docker, Tomcat, Jenkins, OSGi, REST