Polimill builds Japan's next-generation public AI infrastructure

Polimill began with Surfvote, a platform where citizens can exchange views about politics and society. As the company worked with local governments, it saw a structural challenge: public-sector teams were consumed by daily operations and had little time to reflect citizens' voices in policy.

To expand civic participation, Polimill first needed to make government work itself more efficient. The company started building a generative AI platform for public-sector workflows and released QommonsAI in October 2024. Today, QommonsAI provides specialized AI across areas such as assembly response, public services, social welfare, and legal search. About 1,050 municipalities and about 550,000 public employees across Japan now use it. Built with OpenAI technology, QommonsAI is evolving beyond a staff productivity tool into what Polimill sees as a public OS for municipal work in Japan.

Amid a worsening labor shortage, using AI to make government work more efficient is essential. But introducing separate tools can create service gaps between municipalities. That is why we want QommonsAI to become a common foundation that supports every municipality equally—and grow into the public OS that supports Japan's government.

Masahiro Wakabayashi, CAIO, Polimill

Building a cross-municipality knowledge base

One of the biggest obstacles to bringing generative AI into government was fragmented data. Each municipality has its own workflows and document formats, and past records are scattered. For example, preparing assembly responses can require manually reviewing years of minutes to ensure an answer is consistent with prefectural policy. Even the most capable AI model cannot produce practical insight if the underlying data is not organized.

Polimill collected and standardized assembly minutes from across Japan, then used AI to add metadata and build a high-precision search foundation that works across municipalities and time periods.

The company expanded this structure beyond assemblies into welfare, laws, and other administrative domains. By bringing specialized data and AI into one platform and making it searchable through a common interface, QommonsAI turns distributed administrative information into knowledge that can be used in daily work. That structure is the foundation for Polimill's vision of QommonsAI as a shared platform for government.

Balancing government-grade security with everyday usability

OpenAI's GPT models are core to QommonsAI. In the public sector, information management and audit readiness are essential. QommonsAI includes operational controls that let administrators review feature usage history and limit which models are available according to organizational policy.

At the same time, Masahiro Wakabayashi, Polimill's CAIO, points to GPT models' broad capability and familiarity as the main reasons for adopting them. The widespread awareness of ChatGPT matters when public employees need to use a new tool after rollout. Even if they are not familiar with technical terms or other model names, knowing the system is based on widely used ChatGPT technology lowers the initial barrier to adoption.

According to Polimill, GPT models are the most frequently selected option for everyday work in QommonsAI's general conversation feature. From reading files to supporting daily dialogue, GPT's ability to respond reliably to a wide range of work requests in a single model helps QommonsAI take root in the field.

Codex and hands-on support made development 3-5x faster

OpenAI technology has also changed Polimill's development process. The company adopted Codex across the workflow, from requirements definition to checking consistency with existing GitHub code, implementation, and testing. Engineers can focus on reviewing AI-generated plans and making high-level decisions, while AI carries out more of the implementation work autonomously.

With AI coding speed and continued background work, development speed rose to 3-5x previous levels. Wakabayashi says the validation cycle of building prototypes, showing them to municipal teams, and gathering feedback has accelerated dramatically.

OpenAI's hands-on support has further accelerated that work. The collaboration includes sharing best practices from advanced global examples, providing information tailored to Polimill, and helping design the development process itself, including which steps AI should handle and where humans should review and take responsibility.

As models and capabilities evolve, AI-assisted development practices also keep changing. It is difficult for individual companies to track advanced global examples and incorporate them into their own engineering organizations. Wakabayashi sees the ability to keep learning from OpenAI and implement those insights inside Polimill as valuable as the API's performance itself.

Results at a glance

With OpenAI technology at its core, Polimill has continued expanding QommonsAI toward a platform for municipal work. Key adoption and usage results include:

- About 1,050 municipalities and about 550,000 public employees across Japan are using QommonsAI.

- Polimill built infrastructure that unifies assembly minutes and administrative information distributed across Japan and makes them searchable across organizations.

- Codex and OpenAI's hands-on support accelerated validation and implementation cycles, increasing development speed by 3-5x.

- GPT models' advanced reasoning helped less-experienced employees use AI and accumulated administrative information to draft policy proposals that approached the quality of proposals from veteran officials.

Beyond efficiency, capturing the tacit knowledge of veteran officials