【C#/Golang/Kotlin/Java, etc.】Server Side Engineer

【 About the company 】
They operate a smartphone application loved by more than 16 million women and a preschool.

Kindergarten Business
- A kindergarten that aims to provide children with the best environment for education in preparation for the AI age.
- We provide Montessori education, bilingual education, and computer science.

■□ Awards
Ranked 27th in the 2019 Best Companies to Work for (Grade Place to Work)
App Annie's "2017 Top Publisher" award

【 Job Description 】

Sensitivity Services and Digital Value Created by Technology
The company is the core development organization of the Cocone Group, which is gaining attention in Japan and other global markets in the avatar social network field.

The company's group aims to create an innovative digital world and deliver new experiences to users around the world by offering a unique combination of avatar and social networking services and by providing gaming services.

The company plays a key role in realizing the group's vision, pursuing sustainable growth and innovation through state-of-the-art technology and creative approaches.

Through rapid and stable service development, they aim to provide services that exceed customer expectations and create a better future through technology.

Founded in 2008, as the engine of the company's growing group, the company embraces a variety of technological challenges and opportunities to drive innovation and create rich digital experiences that connect with users around the world.

Join the company's journey and grow with them as an engineer leading their success in the global marketplace.

【Recruitment Background】
The company was established to strengthen cooperation among the engineering departments of the entire group, which is expanding globally, and to enhance its business and operations.

This is a recruitment opportunity to strengthen the workforce as several new projects are under development at all locations (Tokyo/Fukuoka/Seoul).

【Attractiveness/Job Satisfaction】
・You can incorporate new technologies and services for your service or organization without being locked into the way things have always been done. (e.g. Docker (containers), introduction of new cloud services, technology selection, how to work with existing test cases, etc.)
・In addition, the company develops new services every year, and you will be involved in PJT from the very beginning as a member of the new start-up team.
・You can be involved in high-traffic services not only in Japan but also on a global scale.


・Experience developing in-house services in the BtoC domain in the social gaming industry
・Knowledge of distributed system architecture
・Involved in infrastructure and front-end (web) development, although the main implementation is server-side development.
・Involvement in specification selection from the service planning stage.

【Responsibilities】
[Immediately after hiring]
You will be responsible for the development and operation of social applications for AppStore and Google Play. You will not be required to work based on specifications, but will be able to work on optimal design, development, and operation from an engineer's point of view, with your own ideas.

【In-house Projects】
Participation in projects not only in Tokyo, but also in the group's global bases (Fukuoka/Seoul) is possible.
Example: Not transferring, but taking charge of a product in Fukuoka or Seoul from Tokyo, etc.


・Design, development and operation of server-side applications
　・Development and management of authentication functions
　・Development and operation of business logic
　・API implementation
　・DB design (using NoSQL / RDBMS)
　・Load management
・Various server configurations
　・Web server, application server, backend server
　・Tuning and performance optimization of various servers
・Work automation
　・Testing, deployment, coding conventions, etc.


・Server development and maintenance for casual competitive games
・Design and implementation of real-time multiplayer server
・Gameplay data management and performance optimization
・Design and implementation of server logic, matchmaking, and ranking systems
・Deploy and manage servers in cloud environments (AWS, GCP, etc.)
・Optimize network performance and enhance security
・Work with client teams to provide a stable gameplay environment

[Scope of Change]
Operations designated by the company.

【Technical Keywords】
・Languages: C#, Golang, Kotlin, Java
・HTTP Server / Reverse Proxy: nginx, Tomcat
・OS: Linux
・Database / Cache: MariaDB, MongoDB, Redis
・Cloud: AWS, GCP
・Framework: Spring Framework, Spring Boot
・IDE: IntelliJ, VS Code
・Script: Python, JavaScript, Bash, node.js, etc.
・Build automation: Jenkins, etc.
・Other tools: GitHub Enterprise, GitHub Copilot, ChatGPT Plus

About Full Remote Work
■When coming to the office
*If you come to work at a base according to the company's instructions, the following measures will be taken.
①Working hours
１Less than 150 km one way from home
The start time of work at the base is considered the start time of work and the end time of work is considered the end time of work.
(Travel time from home to the base is not considered as working hours.)
・More than 150 km one way from home
The start time of work at the base is considered the start time and the end time of work is considered the end time. ・However, if an employee does not work during core hours due to travel from home to the base, the employee is considered to have worked during core hours.
②Transportation expenses
Daily transportation expenses from home to the base will be paid (based on IC card). (IC card basis)
③Lodging expenses
If lodging is required, the actual cost will be reimbursed.
④Daily allowance
No allowance will be provided.

■Remote work allowance
10,000 yen/month

■About the company cafeteria
For full remote workers, there is a charge for using the deli when coming to the office.

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【 Working conditions 】

【Welfare】
The company also offers a unique welfare program that allows employees to experience a sense of fulfillment.
■Cocone Deli
A dedicated chef provides meals that are healthy and well-balanced for employees.
■Coco Cafe
A dedicated barista serves café lattes, teas, and seasonal menu items.
■Cocone Gym
Cocone Gym offers free use of the gym and group lessons to support the health and fitness of each employee (personal lessons are available for a fee). (Personal lessons are available for a fee.)
■In-House Massage
Qualified massage therapists provide massages in a dedicated relaxation room according to the preferences and physical condition of employees.
■Five-Year Completion Leave
For every five years of service, employees are entitled to 30 days of special leave for creative rest and new sources of vitality.
(Eligible full-time employees)
■Childcare Free Time
At your discretion, you can use “the number of weekdays you work x 60 minutes” each month for transporting your child to and from work, participating in events, visiting the hospital, nursing your child, etc.
This system can be used until the younger child enters the 6th grade of elementary school.
(Eligible employees: those who have completed the probationary period of regular employees)
■Tuition Support for Preschool
Partial tuition support for “International Montessori Mirai Kindergarten” operated by a subsidiary of Cocone.
■Engineer Skill Support Program
The purpose of this program is to improve the skills and expertise of Cocone engineers. The company pays half of the cost of books and online courses related to development technology so that they can actively use them. (Up to 10,000 yen per quarter *No carryover)

【Holidays/Vacations】
2 days off per week (Saturdays, Sundays and national holidays)
Year-end and New Year vacations
Celebration or condolence leave
Paid leave
Maternity leave
Childcare leave
Nursing care leave

【Required】
5+ years of experience in server-side application development/operation (B2C/B2B unrelated)
Proficiency in one of the server development languages such as C#, Golang, Kotlin, Java, etc.
Experience in TCP/UDP network programming
Experience in game server development (experience with real-time multiplayer games preferred)
Experience in database design and optimization (MySQL, MongoDB, Redis, etc.)
Experience deploying and running servers in a Linux environment
Experience working collaboratively using Git

【Preferred】
Experience in server development and operations for casual games
Experience in handling large scale traffic
Experience operating servers in a cloud environment (AWS, GCP, Azure)
Experience with containerization technologies (Docker, Kubernetes)
Knowledge of game security and cheat protection
Experience implementing matchmaking algorithms
Teamwork oriented and enthusiastic

【Ideal Applicants】
Able to have fun and continue to explore new technologies.
Highly motivated to improve services, with strong drive and determination
Able to take action to scale up the entire team and influence each other positively