Back End Developer

About the opportunity

We are hiring a Senior Backend Engineer to join an international AI engineering team in Tokyo.

The team develops and operates a large-scale machine translation and machine-learning platform supporting real-time and batch workloads across multiple digital services.

This is a hands-on engineering position for someone with strong experience in backend development, distributed systems, cloud-native platforms, event-driven architecture, and production operations. Previous machine-learning platform experience is valuable, but candidates with exceptional high-scale backend experience and an interest in AI infrastructure are also encouraged to apply.

What you will work on

You will contribute to a platform that exposes machine-learning and translation capabilities through reliable production services.

Responsibilities include:

• Design, develop, test, and maintain distributed backend services
• Build and improve real-time and batch-processing APIs
• Develop reliable asynchronous and event-driven workflows
• Improve latency, throughput, scalability, and infrastructure efficiency
• Deploy and operate services using GCP, GKE, and Kubernetes
• Support production systems running on Linux
• Design messaging workflows using Kafka, Google Pub/Sub, or similar technologies
• Improve autoscaling, observability, deployment, and rollback processes
• Work with relational databases, caching layers, and search technologies
• Collaborate with machine-learning engineers on inference and model-serving workflows
• Produce technical designs, implementation documentation, and operational procedures
• Participate in code reviews, system-design discussions, troubleshooting, and continuous improvement
• Collaborate with international engineering teams across Japan and India

Required experience

• Approximately five or more years of professional software-engineering experience
• Strong backend development experience in at least one of:
• Go
• Python
• Java
• C++
• Rust
• Experience designing and operating microservices or distributed systems
• Experience with event-driven architecture or messaging technologies such as:
• Kafka
• Google Pub/Sub
• Pulsar
• RabbitMQ
• NATS
• Amazon SQS
• Experience with Kubernetes and containerized production workloads
• Strong understanding of relational databases such as PostgreSQL or MySQL
• Experience with Linux-based production systems
• Understanding of concurrency, asynchronous processing, worker-based systems, and failure recovery
• Experience owning services from design and implementation through deployment, monitoring, and production support
• Professional English communication skills

Highly desirable experience

• Google Cloud Platform and Google Kubernetes Engine
• Horizontal Pod Autoscaling and Kubernetes resource optimization
• Terraform, Helm, Argo CD, or similar deployment tools
• Batch-processing or workflow-orchestration systems
• Airflow, Temporal, Spark, Flink, or distributed worker architectures
• Model serving, online inference, or batch inference
• MLOps or machine-learning platform engineering
• NVIDIA Triton, ONNX, KServe, Ray Serve, vLLM, or Vertex AI
• NLP, machine translation, semantic search, recommendation systems, or vector search
• PostgreSQL query optimization, indexing, Redis, or Elasticsearch
• Prometheus, Grafana, OpenTelemetry, Datadog, or similar observability tools
• Performance engineering involving RPS, QPS, p95, or p99 latency
• Experience leading technical design reviews or mentoring engineers

Working conditions

• Location: Tokyo, Japan
• Workplace: On-site
• Working hours: 9:00 AM to 5:30 PM, Monday to Friday
• Contract: Initial two-month contract followed by three-month renewals
• Compensation: Up to JPY 7 million annually, depending on experience and interview performance
• Working language: English
• Japanese: Not required

Overseas applicants

Applications from candidates currently outside Japan are welcome.

• Japanese work visa sponsorship is available
• Candidates must be willing to relocate to Tokyo and work on-site
• Flights, initial accommodation, shipping, and other relocation expenses must be self-funded
• Candidates should carefully consider the compensation and renewable-contract structure before applying
• The successful candidate must be able to complete the visa and relocation process within an agreed timeframe

Application requirements

Please submit an up-to-date, detailed CV showing:

• Technologies used in each role
• Personal responsibilities and ownership
• Production scale, such as RPS, QPS, transactions, events, users, or data volume
• Performance or reliability improvements
• Cloud and Kubernetes responsibilities
• Messaging, batch-processing, or distributed-systems experience
• Availability and notice period
• Current location and relocation readiness