DESIGN × ENGINEERING / COIAI
Your development partner across design and technology. From systems that run your operations and AI that uses internal knowledge to web, apps, and XR that reach people, we connect understanding the problem with delivering something useful.
01 / SERVICES
Improve operations, use internal knowledge, or launch a new service. We combine the disciplines each goal needs, connecting ideas with implementation and improvement.
01 / Discovery / custom development / migration
Connect operations. Prepare for change.
Understand fragmented information and business-specific rules. Analyze existing assets, then design, build, and migrate priority workflows in stages.
Explore this service →
02 / Hardware / internal RAG / operations and training
Put internal knowledge to work.
Build private AI with permission-aware retrieval. Support spans hardware and model selection, document management, performance validation, and staff education.
Explore this service →
03 / UI/UX / web / mobile and desktop
Make every interaction useful.
Connect product concepts, information architecture, and UI/UX with web, mobile, and desktop implementation. Design for the people using and maintaining the product.
View web and app work →
04 / AR / VR / 3D content
Let people experience the idea.
From true-scale furniture AR to location-based VR and 3D content, design around the setting, device, and the way people move through an experience.
Explore this service →02 / OUR APPROACH
From observation to insight, from insight to value. We take time to understand the context and make the reasons behind design and engineering decisions clear.
Connect the user’s perspective with engineering and operations.
Look beyond requested features to how people actually work. Understanding the surrounding processes helps identify the problem and establish useful priorities.
Interface decisions connect to data, logic, and operations. Engineers speak directly with the people involved and consider usability alongside technical feasibility.
Prototypes and focused increments reveal misunderstandings early. When needs change, assess the impact and agree what should happen next.
Consider migration, onboarding, operating guides, and the division of maintenance and improvement work. Leave people equipped to make the next decision.
03 / IN PRACTICE
A core system rebuild and a deployed internal AI environment. Explore the actual scope of our work and the current stage of each engagement.
Selected and in delivery
We are analyzing a complex legacy environment and rebuilding it in stages without losing the business rules accumulated over years of operation.
Deployed in a live environment
We built an environment that searches internal documents without sending them to an external service and respects each user's access permissions.
Client identities and engagement-specific figures are withheld. The core system is in development; the AI environment is deployed. Unmeasured improvements are not presented as outcomes.
04 / SELECTED WORK
UI design, internal applications, brand identity, and VR content. Commissioned work and our own products are identified with the contribution we made.
Commissioned work / UI/UX Design
Concept design and information architecture for "moneychat", a financial learning service by Steins Inc.
Commissioned work / Enterprise App
Internal application for Big Field Inc. Allows easy creation of product samples during product planning.
Own product / Desktop App
Released "Folder Icon Customizer", an app for macOS.
Commissioned work / Branding
Designed corporate identity for chance Inc., a multifaceted healthcare provider.
Commissioned work / VR / 3D
Architectural modeling of Shuri Castle and character creation/modeling of "Majimun".
05 / PROCESS
The process fits the project’s scale and starting point. Each stage produces something to review and information for the next decision.
Understand the problem, users, existing systems, and timing. Identify what needs investigation.
Problem statement and discovery scope
Assess business and technical constraints, prototype interfaces, and clarify scope and costs.
Design, prototype, and proposal
Develop priority areas and verify them through reviews and tests grounded in real workflows.
Working software and test results
Support migration, onboarding, and operational handover. Agree maintenance and improvement scope.
Operating guides and improvement plan
06 / PEOPLE & COMPANY
PEOPLE / DEVELOPMENT
Working across UI/UX, web, applications, and XR to connect the experience people use with the systems behind it.
COIAI INC. / TOKYO
Based in Nerima, Tokyo, coiai values work that is thoughtfully designed and functions reliably. We learn the industry and workflows behind each project and carry that understanding through discovery, design, implementation, and operations.
AWARD / 2024
Vice Governor's Award Winner
Participated in the 2024 Tokyo Open Data Hackathon, which had approximately 1,000 participants. Our team, "Hacking the Debt," was selected as one of the top 30 finalists and received this award.
07 / INSIGHTS
Technical explorations and the context behind our development work.
When managing versions of dependencies, GitHub Actions, and Terraform providers, it's tempting to simply chase the latest release at all times. This post walks through a real team discussion about whether to pin versions, and explains why "pin + automated bumps" with Dependabot gives you both safety and freshness.
Read article →
I started building an on-premises AI server (local LLM + internal document RAG) on a GMKtec EVO-X2, a mini PC powered by the AMD Ryzen AI Max+ 395. This is my day-one work log, covering the two traps I hit along the way: an install USB that refused to boot, and a wired LAN port the OS simply couldn't see.
Read article →
An introduction to Feature-Sliced Design (FSD) v2.1, a frontend architecture that organizes code by pages and entities rather than by responsibility. It covers the core concepts of layers, slices, and segments, along with handy tools like the Steiger architecture linter and the official Claude Skills for AI-assisted coding.
Read article →Ideas to help evaluate modernization and operational improvement.
Conversations about making products and building a business.
Articles could not be loaded. Please try the archive.
Yes. We start with your current challenges and desired outcome, then identify research and priorities. Any paid investigation or development is scoped and quoted before proceeding.
Yes. We review your team, available materials, and the stages you need, then propose clear responsibilities and deliverables.
Beyond functionality, the state of existing documentation, integrations, migration data, validation, and support all matter. We discuss priorities and consider a phased approach.
LET’S TALK
Tell us what is difficult today and what you want to make possible. We can start by clarifying the scope, constraints, and practical next steps together.
Enquiry → review and reply → discovery conversation → proposed next steps. Research and development costs are proposed after clarifying the scope.