Yoann Caplain, Developer in Montélimar, France
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Yoann Caplain

Verified Expert  in Engineering

Software Developer

Montélimar, France
Toptal Member Since
April 27, 2021

Yoann loves solving hard technical issues, working on exciting projects, delivering value to clients and users, learning new things, and collaborating with outstanding professionals. He looks for back- and front-end development projects with a variety of Java- and JavaScript-related technologies.


Java, Kotlin, Scala, Spring, Lagom, Play 2, Azure, SQL Server 2015, Kubernetes...
Allure Systems
Java, Spring, Hibernate, PHP, Symfony, JHipster, Apache, CentOS, Windows Server...
C#, Visual Studio, JetBrains Rider, Networks, Git, APIs, GitHub...




Preferred Environment

Kotlin, Java, Spring, JOOQ, Hibernate, Angular, Kubernetes, Docker, Azure, Amazon Web Services (AWS)

The most amazing...

...projects I've developed are two open-source applications used by the community, one for JHipster and another to control Canon cameras.

Work Experience

Senior Software Engineer Back-end R&D

2019 - 2021
  • Managed a team of junior developers including train and code review.
  • Worked on more than 20 different microservices, each with unique combinations of languages and frameworks.
  • Communicated with other team members to provide consistent API and feature development.
  • Worked with a variety of IoT solutions such as door locks and climate control devices. Integrated different companies' APIs into a single model for internal use in the company.
  • Maintained Azure CI/CD, bus, storage, and gateway with different environments.
Technologies: Java, Kotlin, Scala, Spring, Lagom, Play 2, Azure, SQL Server 2015, Kubernetes, Docker, Microservices, WeChat Pay, Alipay, Hibernate, Akka, Zipkin, Redis, IntelliJ IDEA, Windows, IT Management, CentOS, Apache Maven, SBT, Internet of Things (IoT), Azure Blob Storage API, Azure Application Gateway, Spring Boot, Spring Cloud Sleuth, Spring Data, Spring Cloud, Flyway, Databases, Debian, MySQL, JOOQ, Mobile, DB, REST, JavaScript, Microsoft SQL Server, Git, Play Framework, Slick, DevOps, Domain-driven Design (DDD), Apache Kafka, CSS, APIs, SQL, HTML, CQRS, REST APIs, XML, GitHub, Payment APIs, Azure DevOps, API Integration, API Development, Back-end, Java 8, Java 11, Java 15, Relational Databases

Lead Software Engineer R&D

2016 - 2019
Allure Systems
  • Oversaw the complete IT office in Shanghai, including technology design and choice, system administration and network management, and managing software and back-end software engineers.
  • Developed back-end software for web and internal tools.
  • Integrated the bridge between internal software in Java with external libraries in C, using JNA and JNI.
  • Managed a team of three developers. Used management tools like YouTrack.
  • Maintained and upgraded a network within the company office. Ensured excellent quality of service for 100+ TB of data transfer daily.
  • Maintained and built PCs for employees with specific configurations to handle image retouching and efficient file I/O.
  • Maintained and created servers with CentOS 7, Windows Server 2016, and CentOS for the company's SaaS platform. Also used Windows Server internally for domain user, file server, and DHCP.
  • Set up internal servers for automatic work (internal scripts, etc.) and set horizontal scaling for processing images and more.
Technologies: Java, Spring, Hibernate, PHP, Symfony, JHipster, Apache, CentOS, Windows Server, JOOQ, Angular, Apache Maven, Amazon S3 (AWS S3), Windows, Canon EDSDK, Spring Boot, REST, TypeScript, MySQL, JavaFX, Distributed Software, NPM, Webpack, Bootstrap, Liquibase, MapStruct, Sass, YouTrack, TeamCity, C, COM, DHCP, File Servers, FileZilla, SSH, Java Native Access (JNA), Java Native Interface (JNI), IntelliJ IDEA, Databases, Debian, Networks, DB, JavaScript, Full-stack, Git, Bitbucket, Amazon Web Services (AWS), DevOps, CSS, APIs, SQL, HTML, CQRS, REST APIs, XML, GitHub, Payment APIs, Stripe, NgRx, Flexbox, API Integration, RabbitMQ, API Development, Back-end, Java 8, Java 11, Relational Databases

C# Software Engineer R&D

2015 - 2016
  • Created a communication API between the software and hardware.
  • Collaborated with a team of ten developers split between software and hardware specialties.
  • Integrated support of 7+ years of commands inside a single simple-to-use software API for a history hardware commands and data exchange.
Technologies: C#, Visual Studio, JetBrains Rider, Networks, Git, APIs, GitHub, API Integration, API Development, Back-end

Web Developer

2014 - 2015
  • Wrote and maintained a PHP script for a web pipeline.
  • Collaborated with a team of four developers, each responsible for a different part of the product.
  • Added image and video manipulation with FFmpeg and ImageMagick to automatically integrate files sent by clients to fit the product size.
Technologies: PHP, FFmpeg, ImageMagick, NGINX, JavaScript, Full-stack, Git, CSS, APIs, SQL, HTML, REST APIs, XML, API Integration, Back-end, Relational Databases

Canon EDSDK Java

A project intended to grant access to Canon EOS Digital Software Development Kit EDSDK in Java. Features include:

• Take and download pictures
• Set parameters like aperture or ISO speed
• Use live view
• Control multiple cameras
• Simple extendable recorder implementation

Support for MAC OS X is not intended for now, but only a few changes in implementation should be required to make it work; specifically, changes in the library loader class should be needed.

Both 64- and 32-bit versions are supported.


A tool to translate SQL databases to JDL format of jHipster. JDL from the web is OK for a few entities but not for more than 100 entities and relations. UML software and XML exporters could have worked, but many databases in production had to be exported in JDL (faster to generate the JDL from it) and we were already working on a UML design with MySQL Workbench.

REST Filter

A filter that provides consistent functionality to filter and sort for the REST API. It supports JPA criteria and jOOQ dynamic filtering and sorting, tries to make use of Spring Framework optional (but filters already have some annotations from Spring*), and supports Java 8+.

*If Spring Framework is used, it will be added only in the specific package and dependencies will be made optional (true) to limit impact if not used.
2013 - 2016

Master's Degree in Computer Science

UTBM - Belfort, France

2011 - 2013

Bachelor's Degree in Computer Science

ESIREM - Dijon, France


JOOQ, Liquibase, Azure Blob Storage API, Spring Cloud Sleuth, REST APIs, API Development, FFmpeg, Java Native Access (JNA), Slick, ImageMagick, Stripe, NgRx, Flexbox


IntelliJ IDEA, Apache Maven, YouTrack, TeamCity, FileZilla, Azure Application Gateway, Flyway, Git, Bitbucket, GitHub, NGINX, Apache, SBT, Visual Studio, JetBrains Rider, NPM, MapStruct, Travis CI, JHipster, Zipkin, Webpack, Jenkins, RabbitMQ, Apple Aperture


Spring, Hibernate, Spring Boot, Angular, Lagom, Play 2, Akka, Play Framework, Symfony, Bootstrap


Kotlin, Java, Scala, TypeScript, SQL, Java 8, Java 11, Java 15, PHP, C, Sass, JavaScript, HTML, CSS, Python, XML, C++, C#, HTML5


Microservices, REST, CQRS, DevOps, Event Sourcing, Azure DevOps


Databases, DB, MySQL, Amazon S3 (AWS S3), Spring Data, Relational Databases, Redis, Microsoft SQL Server


Windows, MacOS, Linux, Debian, CentOS, Azure, Docker, Kubernetes, Alipay, JavaFX, Apache Kafka, Mobile, Windows Server, Amazon Web Services (AWS)

Industry Expertise



COM, Spring Cloud, APIs, API Integration, Back-end, IT Management, Networks, Canon EDSDK, SQL Server 2015, WeChat Pay, DHCP, File Servers, SSH, Java Native Interface (JNI), Internet of Things (IoT), Full-stack, Domain-driven Design (DDD), Bounded Context Integration, Payment APIs, GPU Computing, ARM, Physics, Mathematics, Cisco, Distributed Software

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