Backend Development Engineer -CPaaS Business Department (RS Product Delivery & Innovation Div)
Rakuten Symphony21 hours ago
Tokyo, JapanSenior
Responsibilities
- Design, implement, and optimize backend microservices for multi-channel communication workloads.
- Build backend capabilities for messaging, identity, verification, and communication APIs.
- Develop high-throughput, low-latency distributed systems for global CPaaS traffic.
- Design database schemas, optimize queries, and maintain database performance.
- Deploy and operate resilient, scalable services on Kubernetes.
- Build scalable APIs and contribute to API-first architecture.
- Manage version-controlled CI/CD pipelines for build validation, automated testing, and deployments.
- Use LLM-based tools to improve code quality, automate documentation, and accelerate workflows.
- Maintain observability using Grafana, Prometheus, and structured logging.
- Collaborate with product, QA, DevOps/SRE, UI/UX, project management, and R&D teams.
- Participate in code reviews and improve engineering standards and practices.
Requirements
- At least 5 years of hands-on backend development experience.
- Strong proficiency in Java or Golang.
- Expertise with Postgres and MySQL.
- Hands-on experience with Kubernetes and containerization.
- Experience with CI/CD pipelines, preferably GitHub Actions.
- Experience with microservices and API-first system design.
- Proficiency using LLM-based tools for coding, automation, and workflow acceleration.
- Advanced English proficiency for communication, documentation, and collaboration.
- Preferred experience with SMPP, SIP, REST APIs, or WebRTC.
- Preferred experience across CPaaS domains including SMS, Email, Voice, Passkey, authentication services, WhatsApp, LINE, and RCS.
- Ability to work effectively in fast-moving, high-autonomy environments.
Tech Stack
Categories
About Rakuten Symphony
Rakuten Symphony builds cloud-native telecom software and services for mobile network operators, including Open RAN platforms, OSS/BSS, and network automation. It sells software subscriptions and deployment/managed services to carriers and enterprises building private networks. Headquartered in Tokyo, it is a business of Rakuten Group, Inc., and its technology underpins the Rakuten Mobile network in Japan, with operations across Asia, Europe, the Middle East, and the Americas.