Freelancer profile translated to English.

Description

After several years as a freelancer on critical projects involving REST APIs and complex backend architectures, I now support companies on two complementary axes:

Development of robust and scalable applications,
Integration of generative AI into development workflows.

Backend developer / architect specializing in Java, I intervene mainly on:

Design of REST APIs and microservices
Modernization of legacy applications
Refactoring and improvement of software quality
Cloud & Kubernetes architectures
Automation with generative AI
Optimization of development workflows

Main Technologies

Backend

Java 21, Spring Boot, Hibernate, Kotlin, Micronaut, REST API, Microservices

Frontend

Angular, VueJS

(React skills in progress)

Infrastructure & Cloud

Kubernetes, Docker, Azure

Databases

PostgreSQL, Oracle, Redis, Neo4j

Generative AI & Automation

I use generative AI as a development accelerator:

code generation
prompt optimization
automation of technical tasks
assistance with refactoring

My approach remains primarily quality-oriented:

every line generated is validated, corrected, and mastered to ensure reliable, maintainable, and production-ready code.

What I particularly appreciate

Modernization of legacy applications
Refactoring of aging architectures
Solving complex problems
Improving performance and maintainability
Collaborating with demanding technical teams

Certifications

Spring Professional
Redis Certified Developer
Neo4j Professional
CKAD
CCDAK
PSM I
Azure AI Fundamentals

Curious and passionate about new technologies, I enjoy learning, sharing my knowledge, and working on technically stimulating projects.

Classical guitarist in my spare time 🎸

Industry field of expertise

Languages

French
Native or bilingual
English
Conversational
Russian
Native or bilingual
Italian
Conversational

Workplace preferences

Can work on-site

Lyon (up to 50km), Genève (up to 50km), Paris (up to 50km), Grenoble (up to 50km), Nantes (up to 50km)

Welya
On Malt
Java Backend Developer Streaming Platform
TECH
March 2026 - April 2026 (2 months)
New York, United States
Within the Welya development team, I participated in the evolution of the webinar streaming platform as well as the improvement of backend services' performance and reliability.

Missions performed:
Backend development of the webinar streaming and broadcasting platform
Contribution to real-time features for chat and user metrics
Incident correction and bug resolution on Evergreen's chat and reporting modules
Optimization of Java application performance and Hibernate SQL queries
Analysis and correction of backend performance and data access issues
Implementation of PostgreSQL integration tests with Testcontainers
Improvement of software quality and deployment reliability
Participation in the platform's evolutionary and corrective maintenance
This mission allowed me to strengthen my skills in Java backend, SQL/Hibernate optimization, containerized integration testing, and real-time platform development with high usage volume.
Java 21 Hibernate PostgreSQL Spring Boot API
Groupama G2S
Senior Java Developer • SpringBoot • Micronaut • VueJS
BANKING AND INSURANCE
April 2024 - March 2026 (1 year and 10 months)
Écully, France
Within the PWIE agile team at Groupama, I contributed to the modernization of a critical information system by participating in the decommissioning of the Oracle Siebel CRM and the development of a business application used daily by Prévoyance call center advisors.

Backend & Microservices – Java / Micronaut / Spring Boot
Design and development of microservices replacing the Oracle Siebel CRM (person, request, and structure management)
Development from scratch of the PIVOT microservice in Micronaut for multi-criteria search
Implementation of a Redis cache strategy via Spring Gateway to optimize performance and reduce redundant calls
Development of REST APIs with an OpenAPI First approach for the PWIE project's Backend For Frontend (BFF)
Contribution to a GraphQL microservice dedicated to contract display
Participation in microservices architecture and target IS evolution
Frontend – VueJS 3 / Microfrontend
Development and debugging of the PWIE application in VueJS 3 within a Single-SPA microfrontend architecture
Development of business features used in production by Prévoyance advisors
Frontend/backend integration and user experience improvement
Teamwork & Agile Methods
Work within development teams of about 10 people in a large account environment
Participation in Agile ceremonies: sprints, daily meetings, refinements, demos, and retrospectives
Code reviews and collaboration with other developers to ensure code quality and consistency
Development of unit and integration tests to secure application evolutions
Adherence to quality standards and participation in continuous improvement of development practices
Cross-functional collaboration with backend, frontend, and architecture teams in an IS modernization context
Java 21 SpringBoot Microservices JPA/Hibernate Oracle
Cosmo Tech
On Malt
Cloud Simulation Platform Evolution
SOFTWARE PUBLISHING
August 2022 - October 2023 (1 year and 2 months)
Lyon, France
Cosmo Techis an international publisher of digital twin solutions that enable industrial companies to model, simulate, and optimize their operations at scale.

Within the SDK team, I participated in the evolution of the cloud platform and the modernization of its technical architecture in a Kubernetes and Microsoft Azure environment.

Missions performed:
Development of the Dataset module for managing and integrating business data
Development of backend APIs in Kotlin
Design and development of the RBAC module (role and permission management)
Integration of Redis Stack to improve performance and independence from proprietary cloud services
Participation in the migration and replacement of Azure Cosmos DB with Redis Stack
Development of Kubernetes automation scripts in Python
Contribution to the implementation of a clustered Kubernetes platform independent of Azure cloud services
Automation of deployment and administration operations for technical environments
Participation in the evolution of cloud-native architecture and distributed components
This mission allowed me to strengthen my skills in cloud architecture, Kubernetes, Python automation, Kotlin backend development, and the design of distributed platforms focused on high availability and multi-cloud portability.
Spring Boot Kotlin Kubernetes Redis Microsoft Azure

Check out Sergey's experience

Account deleted

Reviewed on 5/9/2020

Sergey is both an artist and a visionary. He works well with ambiguity, communicates well and sticks to the project to deliver a great product. He had freedom in choosing the design given the requirements, and I believe his choices were good and sound. Thank you for all your efforts!