Software Engineer, Platform Engineering

📋 Job Overview

Join Mercari's Platform Engineering team to lead the creation of Japan's first on-premises GPU infrastructure. This is a unique opportunity to build from the ground up, managing data-center facilities, network infrastructure, and operations for AI/GPU workloads. You'll collaborate closely with Corporate IT and various stakeholders to ensure seamless integration with existing cloud and platform networks.

🏢 About Mercari

Circulate all forms of value to unleash the potential in all people
What can I do to help society thrive with the finite resources we have? The Mercari marketplace app was born in 2013 out of this thought by our founder Shintaro Yamada as he traveled the world. We believe that by circulating all forms of value, not just physical things and money, we can create opportunities for anyone to realize their dreams and contribute to society and the people around them. Mercari aims to use technology to connect people all over the world and create a world where anyone can unleash their potential.

🎯 The Role

You will own the on-prem side of Mercari's new GPU infrastructure, securing data-center facilities and building the network foundation that enables GPU compute. This includes designing, building, and operating the on-prem DC/GPU infrastructure, from data-center facilities to the supporting network. You'll also integrate this securely with existing corporate, cloud (GCP/AWS), and platform networks. Regular physical visits to our data center are required for hands-on networking work.

✅ Key Responsibilities

• Design, build, and operate Mercari's on-prem DC/GPU infrastructure, including data-center facilities (racks, power, cooling) and the supporting network
• Design and build the network foundation for GPU workloads: compute fabric (InfiniBand/RoCE), storage/in-band, service network, and isolated OOB management
• Design, configure, and operate routing for the on-prem GPU fabric and its cloud/platform interconnects using BGP (and OSPF/IS-IS, VLAN/VRF as needed)
• Coordinate with data-center providers and SI partners on facility readiness, equipment procurement, lead times, and remote-hands/installation work
• Manage Mercari's internal data center end to end, including vendor/SI discussions, commercial negotiations, and contract & procurement handling
• Perform hands-on, on-site data-center networking work — running and changing cabling, and configuring routers, switches, firewalls, and other network devices
• Integrate the on-prem DC/GPU environment securely with existing corporate, cloud (GCP/AWS), and platform networks
• Establish monitoring, alerting, logging, and operational handoff for GPU systems and network devices
• Support GPU PoC execution and help define the path from PoC to production
• Automate provisioning and operations, and manage configuration as code (IaC)
• Collaborate closely with the Corporate IT team on data-center facilities, connectivity, and on-site operations
• Collaborate with ML Platform, Infrastructure, Security, and Procurement stakeholders
• Own data-center facility readiness (rack, power, cooling, carry-in routes), including NVIDIA pre-delivery site survey confirmation for DGX B200/B300-class nodes
• Drive RFP, quotation, and vendor selection cycles with partners, and own NDA, R&R/RACI, contract, and PO handling together with Procurement
• Prepare technical and cost materials for internal approval gates, including TCO/ROI comparison against cloud GPU/TPU
• Build and operate storage and dataset paths for models and checkpoints, and keep the stack portable between on-prem and GCP/GKE
• Define and operate SLOs, on-call, incident response, runbooks, and BCP/DR for the on-prem inference environment
• Bring on-prem GPU and compute nodes to parity with Mercari's cloud security posture
• Track and report GPU utilization, power, and token-cost savings with FinOps

📌 Required Qualifications

• Strong networking fundamentals (TCP/IP, IP address management, OSI layers 2–7, routing, DNS, TLS, HTTP)
• Hands-on experience designing, configuring, and troubleshooting data-center routing and switching, especially BGP (ASN planning, route summarization, and routing policy)
• Hands-on experience designing and operating physical/data-center networking (switches, routers, firewalls, structured cabling)
• Production experience operating Linux servers
• Hands-on data-center experience, including for GPU/high-density systems: physically installing and changing cabling and configuring routers, switches, and firewalls on-site
• Experience with data-center operations: racks, power, cooling, cross-connects, and coordinating remote-hands / installation work
• Hands-on experience with data-center physical/facility operations, including power equipment and circuit switching, and responding to outages and production incidents
• Experience managing data-center vendors and SI partners, including commercial discussions and contract/procurement handling
• Experience integrating on-prem and cloud networks (GCP or AWS), including VPN, proxies, and routing
• Security mindset in network design and operations: firewall rule design and management, egress/outbound policies, and network segmentation/isolation
• Ability to automate workflows using Python or Bash and to manage configuration using Infrastructure as Code (IaC)
• Experience writing design documents and working with internal stakeholders and external vendors/SIers
• Experience running production infrastructure in Japanese data centers, including carry-in planning, site surveys, and facility coordination conducted in Japanese
• Experience operating Linux/GPU nodes as a fleet: provisioning, firmware and driver lifecycle, monitoring, and incident response
• Experience defining SLOs and participating in on-call for a production platform
• Experience producing internal approval and procurement documentation for executive-level review
• Empathy with Mercari's mission and values

⭐ Desirable Experience

• Experience with GPU/HPC infrastructure and high-performance fabrics such as InfiniBand or RoCE
• Experience designing modern data-center fabrics: spine/leaf and border-leaf architectures, and EVPN-VXLAN
• Experience with networking for bare-metal provisioning, such as DHCP-relay and PXE boot design
• Hands-on experience installing and maintaining GPU systems/servers in a data center
• Experience operating NVIDIA DGX or similar GPU appliances
• Experience with out-of-band management (BMC/Redfish/IPMI) and PDU management
• Experience designing high-density data-center environments (high kW/rack, cooling strategy)
• Knowledge of ML/LLM serving infrastructure and GPU scheduling
• Experience working with SI partners and procurement processes
• Experience developing infrastructure or middleware using Go or Python
• Experience operating LLM inference in production with vLLM, NVIDIA NIM/Triton, or similar
• Experience with GPU scheduling and orchestration: Kubernetes with GPU Operator, Run:ai, or Slurm
• Experience with hybrid GCP integration: GKE, Workload Identity Federation, split-horizon DNS, and cloud fallback paths
• Familiarity with NVIDIA AI Enterprise licensing and support contracts, and with Japanese vendor/SI management
• Experience extending security posture tooling from a cloud estate to on-prem nodes
• Knowledge of PCI-DSS or ISMS requirements as they apply to in-scope network and data-center environments
• Experience with high-performance storage for AI workloads (Lustre, VAST, WEKA) and object-storage/GCS dataset pipelines

🎁 Benefits

Competitive salary and benefits package. Mercari offers a comprehensive benefits program that includes health insurance, retirement savings plans, and other employee perks. The exact details of the compensation and benefits will be discussed during the interview process.

🛂 Visa & Eligibility

Mercari is committed to equal opportunity and diversity. We welcome applications from all qualified candidates regardless of their background. Work authorization in Japan is required for this position.