Lon

CHEN

06 10 79 93 42 lon.chen@lonelytech.fr https://www.lonelytech.fr 27, avenue Jean Jaurès, 14120, Mondeville
With nearly twenty years of experience in IT, I remain a curious and committed technophile. I regularly explore new languages, architectures and paradigms, both front-end and back-end, to continually expand my skills and advance my practice.
I approach projects with pragmatism and critical thinking. Beyond technical expertise, I strive to provide concrete analyses and proposals to effectively contribute to project success.
My core activities include:
- application development and improvement, deployment and monitoring
- design and implementation of appropriate architectures
- experience sharing and technical team mentoring.
I am therefore available for missions oriented towards:
- architecture and application development (design, implementation, automated testing, partial or complete refactoring)
- DevOps (CI/CD, containerization...)
- technical coaching (code audits, internal training, team support)

Professional Experience

Mirakl

Senior Software Engineer

10/2021-Current

Mirakl is a B2B marketplace platform that allows companies to create and manage online marketplaces. As a Senior Software Engineer, I contribute to the development and improvement of the Mirakl platform.

Duties

  • Development of new features for the platform
  • Maintenance and improvement of existing code
  • Collaboration with product and design teams
  • Code review and mentoring of junior developers

Skills

Java, Spring Boot, Microservices, PostgreSQL, DevOps, ArgoCD, K8S, Helm, Terraform, GitHub Actions, Datadog

Methodology

Agile, team of 6 developers

EVoyageurs SNCF - SNCF Gares & Connexions

Senior Developer

05/2021-10/2021

The Gares et Connexions entity of SNCF is responsible for managing the buildings that make up the stations, the equipment they contain, as well as passenger information transmitted by carriers or by SNCF agents. As part of a redesign of the passenger information system in stations, SNCF called on EVoyageurs Technologies to produce a solution that meets their needs. The priorities for this new IS are minimizing infrastructure costs, a cloud-native architecture while respecting demanding quality of service. In response to their request, we proposed a solution with a microservices architecture, using many serverless components (Lambdas, DynamoDB, SQS). This new architecture proposes communication between components via events, and exposes data to the outside via REST APIs or web sockets.

Duties

  • Requirements scoping
  • Definition and proposal of architectures (contextual view, component view, application view)
  • Implementation of proposed architectures
  • Infra-as-Code development via Terraform
  • Data model definition and modeling in DynamoDB
  • Lambda function development in nodeJs and TypeScript
  • Technical foundation setup
  • Test strategy implementation (unit tests, BDD, Cucumber, automation, performance...)
  • Continuous integration setup on SNCF UL (Gitlab, Jenkins, Nexus, Sonar)

Skills

Serverless Architecture, event-driven architecture, hexagonal architecture, NodeJs 12+, TypeScript 4, Terraform, AWS Lambda, AWS SQS, AWS S3, AWS API Gateway, AWS Kinesis, AWS StepFunctions, AWS DynamoDB

Methodology

Scrum, team of 4 dev, 1 AWS SA, 1 ops, 2 QA, 2 PO, 1 SM

EVoyageurs SNCF - Factory Mobilité du Quotidien (ex-Ritmx)

Lead Tech

05/2018-05/2021

EVoyageurs SNCF is the digital factory of the SNCF group. It is responsible for e-commerce sites like oui.sncf, but also in charge of configuration tools, distribution, materialization of SNCF products. The Daily Mobility factory in which I worked for 3 years is notably responsible for the distribution of TER offers.

Duties

  • Implementation of cross-cutting components on Kubernetes (monitoring, logs, storage...)
  • Migration of assets under Kubernetes (dockerization, helm charts, deployments, services, ingresses, jobs...)
  • Supervision and monitoring of assets under Kubernetes
  • Technical roadmap follow-up and management
  • Technical team coaching and mentoring (watch, knowledge sharing, code reviews)
  • UI, API, and batch development
  • Continuous integration setup via Jenkins and gitlab-ci pipelines

Skills

Java11 (corretto), Spring 5, Hibernate 5, Swagger, Flyway, Postgres, Kubernetes, Helm, EFK, Git, jenkins, gitlab-ci, Prometheus, Grafana, OpsGenie, Minio

Methodology

Scrumban, team of 4 dev, 1 ops, 2 QA, 1 PO, 1 SM

Traveldoo - Expedia Group

Developer - Software Architect

04/2017-04/2018

Traveldoo is a company that offers a SaaS platform for business travel management and expense reports in B2B. The company was acquired by the Expedia group. It has many CAC40 players as clients, and continues to shake up the major players in the market. Thus, the company is taking on a new dimension and requires a transformation of the organization and its infrastructure to be able to satisfy the SLAs of its current and future clients.

Duties

  • Architecture and development on the platform's web applications
  • REST API development
  • Batch development
  • Contribution to continuous integration setup

Skills

Java8, Weld, Oracle, Spring Jdbc, ElasticSearch, RestEasy, Swagger, Flyway, Git

Methodology

Kanban, team of 4 dev, 2 QA, 1 PO

Trendstag

Developer - Software Architect

01/2016-04/2017

TrendsTag is a start-up whose product is an application that should allow its users to express their opinion on any subject and anonymously through a vote (UP or DOWN) and an opinion or comments. The different votes make it possible to establish a popularity rating of the subject expressed in the form of a score between 0 and 100.

Duties

  • Infrastructure and environment setup with respect for QOS in production (resilience, performance, security)
  • Continuous Integration pipeline setup with blue/green deployment
  • Email or mobile push notification setup
  • Feature development within the application (score calculation algorithm, personalized feed, api)

Skills

AWS EC2, RDS, ElasticBeanstalk, S3, Java 8, Spring Boot 1.4, Spring Batch, Hibernate 5, Postgres 9. 4, Liquibase, Jersey, Jackson, ElasticSearch, ELK, Jenkins, Git

Methodology

Scrum, 3 architects/developers (1 for front-end in Swift, 2 for Java back-end)

Eileo - Hertz Group

Software Architect

10/2014-10/2015

Eileo is an R&D division of the Hertz group. Eileo's main service is remote fleet management of vehicles. The fleets can be private (eg: City of Paris, CNRS) or part of Hertz vehicles. For Hertz, it was about allowing its customers to rent a vehicle without having to go through an agency. (online booking, check-in, user support, end of booking, billing, payment)

Duties

  • Within the architects team, design of the new architecture around the "Gold anytime" project
  • Implementation of new technical components (frameworks and internal projects)
  • Technical coaching and follow-up of development teams
  • Technical documentation and production support

Skills

Apache Camel, Activiti, Drools, angularJS, CXF, Spring IOC/MVC/Security/Batch/JDBC/Remoting, Lingo (JMS remoting), JMS, activeMQ, elastic search, couchDB, mySQL, git, Jenkins, Sonar

Methodology

Scrum, 5 Archi, 1 SM

Galeries Lafayette

Software Architect - Technical Integrator

11/2011-10/2014

Galeries Lafayette is one of the jewels of French commerce as a brick'n'mortar. However, the group was still too absent on the internet. In this context, the group decided to invest in a new e-commerce platform.

Duties

  • Study, implementation of an ESB within the Galeries Lafayette IS and migration of existing flows to the ESB
  • Technical architecture definition (costing, writing DAG/DAT, coordination with the Grands Magasins IS...)
  • Design and implementation of REST APIs
  • Reception of deliverables and validation of their quality (code reviews)
  • Implementation of continuous integration tools, automated delivery, quality metrics
  • Technical supervision of developers, technical referent with partners

Skills

hybris, Spring IOC, Spring AOP, Spring MVC, CXF, ehCache, JSP, Jquery, Oracle Endeca, Tomcat 6, Oracle 11, Artifactory, Jenkins, Sonar, git, ESB WebMethods

Methodology

Scrum, 15 dev, 2 archis, 4 Ops, 1 DBA, 2 SM, 6 PO

Excilys

Developer

09/2006-11/2011

Consultant developer at major client accounts (SFR, AOL, Neuf, APEC...)

Duties

  • FiaNet - Developer - Participation in the realization of Kwixo, an online payment product C2C and C2B (January 2011 - November 2011)
  • Apec - Developer - Redesign of the portal and APEC IS (May 2010 - December 2010)
  • Neuf Telecom/SFR - Lead dev - Creation of a services portal - customer area (June 2008 - April 2010)
  • AOL France - Developer - Development on AOL's public portal (September 2006 - March 2008)

Skills

Spring IOC, MVC, webflow, Wicket, OpenAM, jmeter, memcached, activemq, CXF, hibernate, GWT, postgres ...

Methodology

V cycle, Scrum, Kanban

Education

Certified Spark training with Hadoop

2015

Professional WebMethods SAG Integration Workshop training

2013

Professional hybris Core Development & Administration training

2012

2-day Professional Wicket training

2010

SCJP 5 Certification

2007

ECE Paris Engineering Degree

2006

DUT in computer science obtained at IUT Paris V

2003

Skills

General

Architecture
Backend Development
Frontend Development
DevOps

Languages

Java
Golang
TypeScript
Python
Shell script

Infrastructure

Kubernetes
Helm
ArgoCD
AWS (Lambda, api gw, sqs, ddb, ...)
Terraform

Frameworks

Spring Boot 3.x
Kafka
Hibernate5
Jooq
QueryDsl
Flyway
Apache Spark
Hazelcast
ActiveMQ
JUnit
Mockito

Tooling and Integration

Git
Maven3
Jenkins
Gitlab-ci
GitHub Actions
Docker
Artifactory
Sonar
webpack

Techniques and Paradigms

BDD
TDD
DDD
EAP
Gang of Four DP

Software

Elastic/OpenSearch
Datadog
Kibana
Logstash
Fluentbit
Grafana
Prometheus
OpsGenie
Kafka
SAP Hybris e-commerce

Cloud

AWS EKS
AWS Lambda
AWS S3
AWS DynamoDB
AWS SQS
AWS RDS
GCP

Testing

Karate
Gatling
Cucumber
Selenium
Postman
Puppeteer

Databases

Postgres 17
ORACLE 9i/11g
MySQL
elastic
couchDB
mongoDB

Web servers/Application servers

NGinx
Apache HTTP
Tomcat
Jetty

Methodologies

Kanban
Scrum
CI/CD
XP

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