Freelancer profile translated to English.

Description

Hello, I am Constantin, a Fullstack software developer, specializing in creating robust and scalable solutions to meet your digital needs.

I combine backend expertise (Java, Spring Boot, microservices) and frontend expertise (React.js, Next.js, TailwindCSS) to design high-performing and elegant platforms.

I also have solid experience in:

- Cloud computing (AWS, Docker): for quickly and efficiently deployed solutions.

- Databases: PostgreSQL, UML/Merise design.

- Performance optimization of your software solutions, enabling the handling of several million requests per minute.

Key Projects:

- Realm Factions: an online game integrated with the blockchain (Solidity, Docker, Vite.js).

- Development of a collaborative tool for a mutual insurance company, integrating Spring Boot microservices.

- Creation of dynamic landing pages for startups (Next.js, TailwindCSS).

I am available for ambitious missions, whether it's creating mobile applications, designing robust architectures, or optimizing your existing projects.

Contact me to discuss your needs!

Industry field of expertise

Languages

French
Native or bilingual
English
Fluent

Workplace preferences

Can work on-site

Tours (up to 50km), Paris (up to 10km), Tours (up to 20km), Orléans (up to 20km)

ApsideTOP
Software Engineer
November 2023 - Today (2 years and 7 months)
Tours, France
Software Engineer at ApsideTOP, I was assigned to MGEN, a complementary health mutual for civil servants, employees, students, and retirees.

- Development of backend components in Java with Spring Boot and microservices.
- Version management with GitLab.
- Unit tests with JUnit5 and Mockito.
- Quality control with SonarQube for continuous monitoring and issue detection.
- Modeling and documentation with UML.
- Agile methodology with sprints, refinements, and daily meetings.
Spring boot Apache Kafka Java17 Docker Products Kibana
Lysero
Founder and Chief Technology Officer
SOFTWARE PUBLISHING
May 2022 - Today (4 years and 1 month)
Paris, France
Lysero is a company specializing in web development and blockchain application development. The company also benefited from incubation at The Place By CCI 37 and is a laureate of the French Tech Tremplin 2025 program.

- Development of an online card game, such as Realm Factions, with blockchain integration using Solidity, ViteJs, and Docker. The project is currently in Alpha version.

- Creation of landing pages in Next.js with Tailwind CSS, such as the company website and the Realm Factions project landing page.

Result: Alpha version launch with a 40% increase in user engagement. The landing page generated conversions for the project.
Next.js Web3.js Solidity Amazon Web Services JavaScript
MGEN
Apprentice Full-Stack Engineer
October 2021 - October 2023 (2 years)
Tours, France
Problem: Lack of collaborative platforms and functional POCs for the IT department.

Solutions: Development of a collaborative platform with WorkAdventure, creation of POCs to improve internal processes, deployment of cloud applications on AWS.

Result: 30% improvement in inter-team collaboration and reduced time-to-market through custom tools.

- Building the collaborative work platform based on the WorkAdventure solution.

- Design of Proofs of Concept (POCs) for IT department users.

- Deployment of solutions on internal or cloud servers (AWS, EC2, ElasticBeanStalk).

- Database design in Merise and UML (PostgreSQL and deployed on AWS with RDS).

- Development in Java with the Spring Boot Framework.

- Creation of a mobile event management application using the Flutter development kit.

- Elaboration of UX/UI mockups and interfaces with the Figma graphic manipulation tool.

- Deployment of an administration interface with React.

- Automation of Docker container deployment with the Jib plugin.
UX/UI Designer figma mockup Java Spring boot PostgreSQL