Job Description: About Organization Core Network Operations Department is responsible for the operation of Rakuten Mobile’s fully virtualized network. We manage critical infrastructure components for the Rakuten Core network, including IMS, RCS, EPC, International Roaming, IoT, and Emergency Services, alongside operational automation using AI. Our mission is to ensure the continuity, reliability, and availability of these services. Our organization consists of 50+ highly skilled Technical SMEs, Operations Engineers, Project Managers, and Problem Managers. We operate a fully virtualized core network leveraging VNF & CNF architectures, supported by an advanced automation & AI framework. 5G SA Launch: With the launch of 5G SA services, we are initiating 5GC operations. Team Strengthening: We are strengthening our capabilities for operating virtualized core network elements. This is essential for ensuring the uninterrupted and reliable delivery of core services through specialized skills, automation, and AI. Scaling Operations: Due to the growing complexity of core technology, the adoption of the latest innovations, an expanding customer base, and the migration to cloud architecture, we require additional resources to manage the increasing workload associated with maintaining virtualized core network elements. Job Duties Responsible for L2/L3 level troubleshooting support for 5GC E2E operations. Provide support for vendor products, troubleshooting and resolving technical issues for Core & Cloud. Manage and resolve complex customer issues escalated from the monitoring support team. Perform in-depth audits and implement improvement plans. Perform regular technical analysis to ensure service optimization and quality. Collaborate with internal teams, partners, and vendors to resolve escalated technical issues and implement corrective actions. Conduct testing and verification of any implemented configuration changes to ensure they meet regulatory and service requirements. Generate reports, analyze service/operational KPIs, and contribute to the improvement of processes and procedures. Document and maintain detailed records of all support activities, including resolutions, troubleshooting steps, and partner interactions. Execute change implementations. Handle communications with other domains. Build knowledge and manage daily operational activities for high efficiency. Collaborate with partners and internal stakeholders to identify issues and fix incidents within the agreed service SLA. Participate in an on-call shift rotation pool. Availability to work occasionally during nights and weekends to provide support for urgent issues or scheduled maintenance. Working from Tokyo office. Minimum Qualifications 10+ years of experience in mobile core network operations/planning. Hands-on job experience with 5GC products. Hands-on job experience with multi-vendor Packet Core products. Hands-on job experience with container-based infrastructure (Kubernetes). Strong knowledge of automation and AI. Preferred Qualifications Deep understanding of mobile network protocols and technologies (e.g., Diameter, GTP, SIP, RTP, and IP-based protocols). Specialization in a specific domain, along with strong technical knowledge of E2E Virtual Core network architecture (IMS, EPC, RCS & CNF). Hands-on experience in CNF-based mobile networks. Experience with monitoring tools, performance analysis, 5G Core & Cloud deployment, and industry-standard KPI/metric analysis tools. Working experience with OpenStack or Kubernetes. Expertise in Method of Procedure (MOP) preparation and validation, as well as configuration implementation. Experience leading Incident Bridges and preparing reports for senior management. Relevant technical certifications. Excellent analytical, problem-solving, communication, and documentation skills. Languages: English (Overall - 3 - Advanced) Looking for members to join our mobile phone business “They cannot succeed if they step into the field at this late date” Some people say Rakuten is reckless in trying to enter the mobile communications business. However, innovation is realized if we succeed when something seems impossible. At Rakuten, we think the world changes when we achieve such changes. Because our history has always been a series of innovations since our establishment. Launching a communication carrier is an opportunity that we have once in our lives. Crack open the current communication industry. Blow new wind into life. Why not create innovation with us? Why not do something big? Job Opening: Regular Employee Company Name Rakuten Mobile, Inc. Qualifications [Required] TOEIC score of 600 or equivalent English proficiency/skills. Rakuten Group Englishnization Rakuten Mobile, Inc. aims for all employees to achieve a TOEIC score of 800 or higher, in line with Rakuten Group, Inc.'s Englishnization policy. As a first step, a TOEIC score of 600 (or equivalent English proficiency) is required for mid-career hires. Job Responsibilities [Upon initial hiring] Varies depending on the position. The scope of work changes may include assignments to other duties determined by the company based on directives, etc. (If a transfer is ordered in accordance with the secondment regulations, the duties will be those of the seconded company.) Contract Period No fixed term Probationary Period Yes (3 months) The probationary period may be extended at the company's discretion. Employment conditions will not change during the probationary period. Work Location [Upon initial hiring] Headquarters (Rakuten Crimson House, 1-14-1 Tamagawa, Setagaya-ku, Tokyo), and other business sites. The scope of work location changes may include reassignments or transfers to locations nationwide and overseas. If remote work is partially permitted, the work location will be the remote work location approved by the company. The work location at the time of hiring will be communicated in the job description for each position and the offer letter. As a measure against passive smoking, smoking is prohibited on the premises of Rakuten Crimson House (however, this may vary depending on the business site). Working Hours Standard working hours: 9:00 AM - 5:30 PM On days when Rakuten Group morning meetings are held, the prescribed working hours will be 8:00 AM - 4:30 PM. Prescribed working hours are 7.5 hours, with a 1-hour break. A flextime system is partially applied. Core time: 11:00 AM - 3:00 PM (8:00 AM - 12:00 PM on morning meeting days) Some positions may differ from the above; details will be specified in the offer letter (e.g., application of discretionary labor system). Overtime work or work on holidays may be instructed. Holidays/Leave/Absence Complete two-day weekend system (Saturday and Sunday) and national holidays Summer vacation, New Year's holiday, annual paid leave, menstrual leave, special leave (condolence, volunteer, etc.) Maternity leave, childcare leave, family care leave Some positions may differ from the above; details will be specified in the offer letter. Salary Monthly salary: JPY300,000 ~ (Breakdown: Base salary JPY 227,848 + fixed overtime pay for 40 hours JPY 72,152) The above is the minimum salary offered for mid-career hires. Overtime work exceeding 40 hours per month will be paid separately as overtime allowance. Some positions may differ from the above; details will be specified in the offer letter (e.g., application of discretionary labor system). Commuting allowance will be provided (conditions and maximum amount apply). Salary Increase Yes Reviewed in January and July based on company performance and individual evaluation. Bonus Yes Paid in June and December based on company performance and individual evaluation. Stock Option Plan Yes Retirement Allowance Yes Insurance Employees' Pension Insurance, Health Insurance, Workers' Accident Compensation Insurance, Employment Insurance, etc. Benefits Cafeteria (breakfast, lunch, dinner generally free) Employee Stock Ownership Plan English learning support, etc. Job Opening: Fixed-term Employee Company Name Rakuten Mobile, Inc. Qualifications Varies depending on the recruiting position. Job Responsibilities [Upon initial hiring] Varies depending on the recruiting position. The scope of work changes may include assignments to other duties determined by the company based on directives, etc. (If a transfer is ordered in accordance with the secondment regulations, the duties will be those of the seconded company.) Contract Period Fixed term Maximum contract renewal period: Yes (The total contract period is 5 years, starting from the initial employment contract date.) Probationary Period None Work Location [Upon initial hiring] Headquarters (Rakuten Crimson House, 1-14-1 Tamagawa, Setagaya-ku, Tokyo), and other business sites. The scope of work location changes may include reassignments or transfers to locations nationwide and overseas. If remote work is partially permitted, the work location will be the remote work location approved by the company. The work location at the time of hiring will be communicated in the job description for each position and the offer letter. As a measure against passive smoking, smoking is prohibited on the premises of Rakuten Crimson House (however, this may vary depending on the business site). Working Hours Standard working hours: 9:00 AM - 5:30 PM On days when Rakuten Group morning meetings are held, the prescribed working hours will be 8:00 AM - 4:30 PM. Prescribed working hours are 7.5 hours, with a 1-hour break. A flextime system is partially applied. Core time: 11:00 AM - 3:00 PM (8:00 AM - 12:00 PM on morning meeting days) Some positions may differ from the above; details will be specified in the offer letter (e.g., application of discretionary labor system). Overtime work or work on holidays may be instructed. Holidays/Leave/Absence Complete two-day weekend system (Saturday and Sunday) and national holidays Summer vacation, New Year's holiday, annual paid leave, menstrual leave, special leave (condolence, volunteer, etc.) Maternity leave, childcare leave, family care leave Some positions may differ from the above; details will be specified in the offer letter. Salary Determined individually based on experience, etc. Commuting allowance will be provided (conditions and maximum amount apply). Salary Increase Yes Upon contract renewal, a salary revision may be proposed based on the most recent evaluation. Bonus May be paid taking into account company performance, general economic conditions, and work performance/abilities. Stock Option Plan None Retirement Allowance None Insurance Employees' Pension Insurance, Health Insurance, Workers' Accident Compensation Insurance, Employment Insurance, etc. Benefits Cafeteria (breakfast, lunch, dinner generally free) Employee Stock Ownership Plan English learning support, etc.

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