Cross Summoner

Date of the project: From 2017 to 2020
Link to the website of the project


This was a completely new E-Commerce Rakuten service that aims at selling goods and services related to Japan soccer (J-League). This is a First Party service model meaning clubs directly sell to customer through this service unlike the Rakuten Ichiba mall model. It helps empower Japan soccer by allowing small clubs that do not have the ressources to sell on a professional site and improve bigger site process and handle huge traffic spikes. This new service handles the entire process of the purchase from the website, to the payment and warehouse operation (stock, order management, etc). I had the chance to be the first on board for that project and started it from scratch.

Role & Responsability

  • Recruitment: present as technical part of the interview process with the managers
  • Mentoring: Training session, pair programming, source code review for team members
  • Management: Members skillset management, support manager in management tasks
  • Planning: Roadmap definition, strategy planning, cost estimation, project management
  • Design: Feature design and review/approval of team member design
  • Development: Framework development and development of difficult cases, team member code review and approval
  • Infrastructure: Infrastructure architecture with INFRA team and CI/CD development
  • Release: Technical release approval and execution (my members or me)
  • Security: In charge of the security protocol implementation for this service at that time


  • Languages: PHP, Java, Javascript, Bash, SQL (Oracle)
  • Middleware: Memcache, Oracle SQL 12c
  • Infra: Rakuten Cloud, Centos 6/7/8
  • Frameworks: Springboot, CodeIgniter
  • Tools: Jenkins, Gatling, Rundeck, ELK
  • Other: GIT, Jira, Confluence, etc


  • High spike traffic with little infrastructure cost that forced heavy caching and optimization (over 1000 qp/s)
  • Working in a complex ecosystem that needed a lot of negotiation with other groups
  • Getting the service up and running with no issue from scratch in 8 months
  • Team member mentoring and leadership in multi-cultural environment
Djem Toker
Djem Toker
Lead engineer

I love technology and especially interested in Web technology, Security, container and virtualization in general, highly scalable and high performance designs, Deep learning, big data and AI