Igor

IGOR BABIY
Senior Java Developer
Lviv, Ukraine | [open contact info](look above in the "contact info" section) | [open contact info](look above in the "contact info" section)
Telegram: @BabiyIgor | Linkedin: [open contact info](look above in the "contact info" section)
English: Upper-Intermediate | Experience: 8+ years

SUMMARY
Result-oriented Senior Java Developer with over 8 years of commercial experience in designing, building, and maintaining highly
scalable backend systems and microservices. Strong expertise in modern Java (11/17/21), Spring Boot, and message brokers (Apache
Kafka). Proficient in cloud infrastructure (AWS) and CI/CD pipelines (Jenkins, Docker, Kubernetes). Experienced in full SDLC, direct
client communication, architecture design, and project estimation. Deep domain knowledge in Casino & Gambling, E-commerce, and
ERP systems.
TECHNICAL SKILLS
Languages: Java (8, 11, 15, 17, 21), SQL, TypeScript/AngularJS (basic understanding for support)
Frameworks & Libraries: Spring (Boot, Security, Data, WebSockets, OAuth 2.0), Resilience4j
Databases & ORM: PostgreSQL, MySQL, SQL Server, H2, Hibernate (HQL, Criteria, 2nd level cache), Spring JPA
Message Brokers: Apache Kafka (2.5+ years of active use), Azure Service Bus
Cloud & DevOps: AWS (S3, Cognito), Azure (AKS, Managed Identity, Azure AD), Docker, Kubernetes, Jenkins, Maven, Git,
BitBucket
Architecture & Tools: Microservices, RESTful APIs, SSO, JSON, GraphQL, Protobuf, Service Discovery (Eureka), Swagger,
OpenAPI, Flyway, Liquibase, Keycloak, Lombok, Thymeleaf
Testing: JUnit 5, Mockito, Testcontainers, WireMock, TDD principles
Other: Redis, Caffeine, Cache2k, Payment Systems (Skrill, Adyen), Firebase Push Notifications
WORK EXPERIENCE
StakeLogicLive | Internet Casino Senior Java Developer | Jul 2023 – Present
Designed and developed roulette microservices from scratch using Java 17-21 and Spring Boot. Analyzed requirements, worked
closely with PAR sheets, and engaged in direct communication with clients, mathematicians, and management. Built volume
estimations and applied TDD practices.
Tools: Java 17-21, Spring (Web, Data, Security, Boot), Kafka, PostgreSQL, Hibernate, Swagger 2, JUnit5, Mockito, HTTPS, WSS.
Stewart (Eastoner) | Senior Java Developer (Contract) | May 2026 – Oct 2026
As part of a 3-developer team, designed and developed from scratch a set of event-driven Java microservices for a title and escrow
accounting platform, covering payments, a double-entry ledger, and ERP (Workday) integration.
Payment Processing: Built the payment disbursement flow and its lifecycle state machine, integrating with an external payment
platform.
Accounting Engine: Implemented a double-entry accounting engine turning business events into balanced journal entries,
supporting reversals and idempotency.
System Integration: Integrated with Workday through an anti-corruption layer (OAuth2/Azure AD, retries, reconciliation).
Asynchronous Messaging: Ensured reliable asynchronous communication with Azure Service Bus via transactional outbox
pattern, idempotent consumers, and dead-letter handling.
Testing & Deployment: Containerized services for AKS; wrote integration tests with Testcontainers and WireMock.
Tools: Java 21, Spring Boot 3.x, Hibernate, SQL Server, Liquibase, Azure Service Bus, Azure (AKS, Managed Identity, Azure AD),
Resilience4j, Protobuf, Docker, JUnit 5, Mockito, Testcontainers, WireMock, Maven.
Lionwood.software | E-commerce & ERP Systems Middle Java Developer | Mar 2020 – Jul 2023
Fast job marketplace: Built backend architecture, configured CI/CD pipelines, integrated AWS S3, and conducted code reviews.
Warehouse Management System (ERP): Developed API structures and CRUD operations for domain entities, managed IIS, and
optimized performance.
Event management App: Defined DB architecture, participated in the Discovery phase, and maintained direct stakeholder
communication.
Xbox games gambling & CRM: Updated backend systems, integrated third-party payment systems (Skrill), AWS Cognito, and
Shopify.
Tools: Java 11-15, Spring Boot, AWS, Azure, MySQL, Docker, Jenkins, WebSockets, Hibernate, SSO, Firebase.

New Tribe Agency | Web & Mobile Solutions Java Developer | Jan 2018 – Mar 2020
Virtual football tournaments app: Built a complex state-machine system for online FIFA tournaments handling pre-
registrations, live brackets, and stats calculation.
E-commerce Platforms: Developed backends and CRM/CMS systems for an online jewelry store and flower platform. Integrated
Adyen payments.
App for car leasing: Developed backend for handling car leasing orders from European vendors.
Tools: Java 8-11, Spring Boot, Hibernate, MySQL, H2, Docker, AWS, Web-Sockets, RESTful APIs, Firebase, JSON, Adyen.