Successful AWS Cost Reduction in Nagoya's Government Cloud Through FinOps Implementation

Metaps Holdings, based in Shibuya, is proud to announce the implementation of its AWS cost management tool, "srest," in Nagoya City. The public release of this case study will take place on September 24, 2025. Following initial testing in March 2025 and a full rollout in June 2025, Nagoya City has successfully optimized its AWS costs and improved operational efficiency. The initiative serves as a pioneering model for fiscal optimization within government cloud environments across Japan.

Introduction

In 2022, Nagoya City developed a digital transformation (DX) initiative aimed at transitioning to a government cloud environment based on AWS. They adopted a highly innovative operational model known as the "single-use method," allowing various operational systems to run on independent AWS accounts while maintaining flexible operations and strong governance.

However, the city faced challenges in tracking costs across multiple accounts and creating efficient billing processes for numerous financial systems. To tackle these issues, Nagoya City was the first in Japan to conduct a practical experiment with "srest" in March 2025, aiming to implement FinOps in the government cloud. The experiment confirmed the effectiveness of srest in collecting and visualizing billing information, as well as allocating costs by business and accounting units, leading to its official introduction just three months later.

Implementation of srest

Context of Implementation

Nagoya City’s push for AWS-based government cloud has set a trailblazing precedent across Japan. The transition to this environment was influenced by their DX promotion policy, with an aim to enhance operational efficiency and cost visibility. Despite the benefits, the city struggled with managing expenses across numerous AWS accounts due to the complexity of data aggregation.

To address this, the city launched its FinOps journey with srest, aiming to streamline cost management processes. This move not only demonstrated the potential of srest but also showcased how agile governance and management can lead to significant fiscal savings.

Benefits of srest Implementation

1. User-Friendly Interface: The intuitive user interface of srest streamlines utilization. Users can see cost breakdowns with just a cursor hover, eliminating the need for extensive training. This allows staff who may not be experts in AWS to easily comprehend their system's cost structure.

2. Efficiency in Billing and Payment Processes: Prior to srest’s implementation, Nagoya City relied on manual processes to consolidate PDF invoices into Excel spreadsheets for monthly cost distribution across various financial accounts. However, with srest's cost allocation functionalities, the city simplified this process, drastically reducing workload while enhancing transparency and accountability among departmental staff regarding their expenses.

3. Cost Structure Visibility: By clarifying the cost structure at the level of individual business systems, the city identified discrepancies in server and monitoring service costs. This timely information enabled them to cut unnecessary expenses, thus achieving more efficient budget management.

About srest

"srest" is an advanced AWS cost management tool designed to integrate cost data from multiple AWS accounts. It supports continuous cost optimization from a FinOps perspective. With its user-friendly dashboard, organizations gain clearer insights into their overall cloud expenditures, improving decision-making capabilities as a result. The tool has successfully passed the AWS Foundational Technical Review and has become an AWS-certified software.

For more information, visit the official website: srest.io

Conclusion

Nagoya City’s journey in leveraging srest exemplifies the future of public sector FinOps practices in Japan. By embracing innovative technologies for cost management, they have taken crucial steps towards achieving sustainable fiscal health in government operations. The results from this case not only serve as a blueprint for other municipalities but also reflect a significant advancement in the government cloud strategy around the nation.

For more details, interested parties can access the interviews and press releases through the links provided: