Java Developer

На данный момент Senior full stack developer.

Мои компетенции и опыт

Leo Wei

SUMMARY

Senior Backend Engineer with 9+ years of experience in developing, architecting, and scaling high-load enterprise systems, including banking, fintech, and SaaS applications. Proven expertise in Java 17+, Kotlin, Spring Boot, Spring Cloud, Hibernate, PostgreSQL, Kafka, Kubernetes, ELK stack, Docker, CI/CD, and microservice architecture. Experienced in distributed systems, asynchronous event processing, REST/SOAP API integration, authentication/authorization (OAuth2, OpenID Connect, JWT), database query optimization, transaction handling, and load balancing. Strong technical leader with hands-on development skills, mentoring experience, and a track record of building maintainable, scalable, and secure systems from scratch.

PROFESSIONAL EXPERIENCE

Senior Full Stack Developer

Micron

Sep 2023 – Present Riga, Latvia

• Lead development of high-load microservices for enterprise banking and fintech applications using Java 17+ and Kotlin, implementing Spring Boot 2.7+, Spring Cloud, Spring Data, Hibernate.
• Designed and maintained microservice architecture, including asynchronous event handling, message queues (Kafka), distributed transaction management, and load balancing.
• Implemented REST and SOAP APIs for internal and external integrations, using OpenAPI 3.0 and secure authentication protocols (OAuth2, OpenID Connect, JWT).
• Optimized PostgreSQL queries for high-volume transactional data, implementing indexes, partitions, joins, transactions, and batch updates for maximum performance.
• Developed asynchronous processing pipelines with Kafka, enabling reliable event-driven workflows across multiple services.
• Deployed microservices in Kubernetes clusters with Dockerized containers; implemented CI/CD pipelines and automated testing with JUnit 5, Mockito, and integration testing.
• Configured observability tools (ELK Stack, Prometheus, Grafana, Jaeger) for monitoring, logging, and tracing high-load systems.
• Conducted code reviews, enforced SOLID principles and clean code standards, and mentored junior engineers on Kotlin and Spring best practices.
• Actively participated in architecture RFCs and ADRs, evaluating trade-offs for microservices, data consistency, and high availability.
• Technical Stack: Java 17+, Kotlin, Spring Boot 2.7+, Spring Cloud, Hibernate, PostgreSQL, Kafka, ELK, JUnit 5, Docker, Kubernetes, CI/CD, Flyway, OpenAPI 3.0, OAuth2/OpenID Connect, Git

Full Stack Developer

UNECOS SOLUTIONS

Apr нужен доступ к резюме Sep 2023 Riga, Latvia

• Developed backend services and APIs using Java 11/17, Spring Boot, Kotlin, and Hibernate, supporting high-load SaaS and fintech systems.
• Migrated monolithic нужен доступ к резюме applications to microservice architecture, designing transactional workflows, asynchronous event-driven services, and fault-tolerant pipelines.
• Implemented Kafka messaging queues for inter-service communication, and integrated Redis for caching sessions and high-performance data retrieval.
• Designed and optimized PostgreSQL database schemas, including complex SELECT queries, JOINs, updates, transactions, stored procedures, and performance indexing.
• Developed secure REST APIs with OAuth2 and JWT authentication for enterprise applications; participated in API versioning and backward compatibility.
• Collaborated on Kubernetes deployment strategies, Docker containerization, and CI/CD automation, ensuring rapid, reliable, and repeatable production releases.
• Led code reviews, enforced clean code practices, and contributed to architecture discussions regarding scaling, asynchronous pipelines, and microservice interdependencies.
• Maintained high code coverage with JUnit 5 and integration tests; refactored legacy modules to increase maintainability and performance.
• Technical Stack: Java 11/17, Kotlin, Spring Boot, Hibernate, PostgreSQL, Redis, Kafka, Docker, Kubernetes, CI/CD, JUnit 5, Flyway, нужен доступ к резюме

Frontend Developer

Onez

• Developed and maintained frontend and backend integration for web applications, supporting Java, нужен доступ к резюме , and PostgreSQL systems.
• Assisted in the development of Java microservices, including entity modeling, REST controller creation, and repository management.
• Optimized backend workflows by refactoring legacy code, implementing modular structures, and improving service response times.
• Participated in Agile/Scrum ceremonies, peer code reviews, and Git-based version control for distributed development teams.
• Coordinated with DevOps and QA teams to ensure reliable deployments and high-quality code delivery.
• Technical Stack: Java 8-11, нужен доступ к резюме , React, PostgreSQL, Redis, REST API, Git, Agile/Scrum

EDUCATION

The Hong Kong University of Science and Technology

May нужен доступ к резюме May 2016 Hong Kong

нужен доступ к резюме in Computer Science & Applied Mathematics

LANGUAGES

English

SKILLS

• Backend Development & Microservices: Java 17+, Kotlin, Spring Boot 2.7+, Spring Cloud, Hibernate, microservice architecture, SOLID principles, clean code, DDD, asynchronous event-driven architecture, distributed transaction management
• Database & Data Management: PostgreSQL (query optimization, indexing, complex SELECT/JOIN, transactions, batch updates, schema design, Flyway migrations), Redis, MongoDB
• Messaging & Integration: Kafka, RabbitMQ, NATS, inter-service communication, asynchronous pipelines, REST/SOAP APIs, OpenAPI 3.0, OAuth2, OpenID Connect, JWT
• Infrastructure & DevOps: Kubernetes (Pods, Deployments, Services, Ingress), Docker, CI/CD pipelines, Sonar, ELK stack, Prometheus, Grafana, Jaeger, monitoring, logging, tracing
• Testing & Quality: JUnit 5, Mockito, integration/unit testing, automated test coverage
• Leadership & Collaboration: Code reviews, mentoring, architecture RFC/ADR participation, Agile/Scrum, cross-team technical discussions, risk assessment, task decomposition