CEM SQM Engineer

Why should you choose us?

Rakuten Symphony is reimagining telecom, changing supply chain norms and disrupting outmoded thinking that threatens the industry's pursuit of rapid innovation and growth. Based on proven modern infrastructure practices, its open interface platforms make it possible to launch and operate advanced mobile services in a fraction of the time and cost of conventional approaches, with no compromise to network quality or security.

Rakuten Symphony has operations in Japan, the United States, Singapore, India, South Korea, Europe, and the Middle East Africa region. For more information, visit:

Building on the technology Rakuten used to launch Japan's newest mobile network, we are taking our mobile offering global.

To support our ambitions to provide an innovative cloud-native telco platform for our customers, Rakuten Symphony is looking to recruit and develop top talent from around the globe. We are looking for individuals to join our team across all functional areas of our business – from sales to engineering, support functions to product development.

Let's build the future of mobile telecommunications together

About Rakuten Group, Inc. (TSE: 4755) is a global leader in internet services that empower individuals, communities, businesses and society. Founded in Tokyo in 1997 as an online marketplace, Rakuten has expanded to offer services in e-commerce, fintech, digital content and communications to 2 billion members around the world. The Rakuten Group has over 30,000 employees, and operations in 30 countries and regions. For more information visit

Role Overview

Seeking a highly experienced professional for
Network KPI analysis, RCA, automation development, and service quality experience improvement initiatives
across 4G/5G domains.

The role involves troubleshooting using CDRs, X2/
S1AP
/RRC signalling, Network KPIs, anomaly detection, and collaboration with IPTX/Device/IMS/Core/RAN/RF teams.

The candidate will drive
daily/weekly/monthly reporting
, and cross-functional initiatives to enhance end-user experience.

Key Responsibilities

1. KPI Monitoring & Analytics

• End-to-end ownership of
  Network KPIs.
• Perform
  daily/weekly analysis
  on network KPIs at device and subscriber-activity (ex. YouTube, amazon, Netflix) level.
• Identify
  worst-performing cells, eNodeBs, gNodeBs, UE models, manufacturer and subscriber-activity
  .

2. CDR (SIP/RRC/X2/S1AP) & Protocol-Level Debugging

• Analyse
  CDRs (SIP/RRC/X2/S1AP) messages
  for failure patterns.
• Troubleshoot issues such as:
• SgNB Addition/Change failures
• NAS EMM/ESM failures
• RLF
• SCG failure information (5G NSA)
• Compare and validate signalling fields , data across different platform and vendor data systems.

3. Data Analysis & Automation

• Work extensively with
  Python (NumPy/Pandas), Excel/ Power BI/SQL
  , and large datasets.
• Build scripts to automate:
• Daily/Weekly report generation
• KPI Anamoly detection
• Device/Manufacturer performance analysis
• Application performance analysis
• Top N device/Manufacturer/application data extraction
• Date/time filtering, binning, and performance trending

4. RCA & Cross-Functional Coordination

• Root Cause Analysis
  for protocol-level failures, outages, and performance drops.
• Prepare
  CTO/leadership presentations
  , highlighting:
• Issue background
• Technical RCA
• Fix actions
• Post-fix improvements
• Pre/Post Comparison

5. Device / Model-Level Performance Analysis

• Compare performance by mobile model (e.g., Google Pixel, Samsung, iPhone).
• Analyse success/failure trends across device categories and OS versions.
• Identify Model/Manufacture specific issues affecting user experience.
• New Device Launch Performance Report

Technical Skills

• Deep understanding of
  LTE/5G NSA Call Flow
  , S1AP, X2AP, NAS signalling, app layer, device log analysis, and TCP/UDP/HTTP/HTTP2 protocols.
• Strong analytical skills in
  Python, Pandas, Excel, SQL
  .
• Experience with
  CDR datasets
  (SIP, S1AP, X2, RRC).
• Knowledge of
  KPI frameworks
  .
• Strong understanding of E2E network
  KPIs
• Hands-on experience with
  Wireshark logs
  .

Soft Skills

• Strong problem-solving and RCA writing ability.
• Able to handle high pressure workloads with structured delivery.
• Excellent communication for cross-team collaboration.
• Ability to present insights to leadership (CTO level).

Qualifications: Minimum Qualification:

• Bachelor's Degree in Electronics/Electronics and Telecomm

Experience:

• 10 years' experience in Telecom service quality management, device log analysis, NAS signalling, app layer, and TCP/UDP/HTTP/HTTP2 protocol level log analysis

  
  

RAKUTEN SHUGI PRINCIPLES:

Our worldwide practices describe specific behaviours that make Rakuten unique and united across the world. We expect Rakuten employees to model these 5 Shugi Principles of Success.

• Always improve, always advance.
  Only be satisfied with complete success - Kaizen.
• Be passionately professional.
  Take an uncompromising approach to your work and be determined to be the best.
• Hypothesize - Practice - Validate - Shikumika.
  Use the Rakuten Cycle to success in unknown territory.
• Maximize Customer Satisfaction.
  The greatest satisfaction for workers in a service industry is to see their customers smile.
• Speed Speed Speed
  Always be conscious of time. Take charge, set clear goals, and engage your team.