Project Overview
A mid-size Japanese municipal government (population ~300,000) was facing a crisis with their citizen services portal. The 15-year-old C#/.NET monolith that handled tax filing, permit applications, resident registrations, and public facility reservations had become increasingly unreliable. During the critical tax filing season (February-March), the system experienced regular crashes that forced citizens to queue in person at city hall — exactly the situation the portal was designed to prevent. The municipality needed a partner who could modernize the system incrementally without disrupting essential services, and who could navigate the complex requirements of Japanese government IT procurement.
The Challenge
The legacy system presented multiple critical issues that threatened both citizen trust and operational efficiency:
- The legacy C#/.NET monolith was built on Windows Server 2008 with direct database queries (no ORM), making it fragile and difficult to maintain
- System uptime during tax filing season was only 92%, with multiple crashes during peak hours causing citizens to lose partially completed forms
- The portal failed to meet WCAG 2.1 accessibility standards — a growing legal requirement for Japanese government services under the Accessibility Law (障害者差別解消法)
- The system could not handle more than 500 concurrent users, yet the municipality was pushing citizens to use online services to reduce in-person visits
- Government procurement regulations required extensive documentation, security audits, and compliance with the Government Common Security Standards (政府統一基準)
- The existing vendor had been maintaining the system for 10 years, and all institutional knowledge of the codebase resided with 2 developers who were both retiring
Our Solution
BCT Global assembled a team of 8: 2 on-site engineers stationed at the municipal IT office for requirements gathering and stakeholder management (both JLPT N2 certified in Japanese), 3 Angular frontend developers, 2 .NET Core backend developers, and 1 DevOps engineer specializing in Azure Government Cloud. We adopted the strangler fig pattern — gradually replacing legacy components with modern services while keeping the system running.
- Phase 1 — Assessment & Architecture (Months 1-4): Our on-site engineers spent 3 months embedded in the municipal IT department, documenting every legacy workflow through interviews with 30+ municipal employees. Designed a microservices architecture on .NET Core with Angular frontend. Selected Azure Government Cloud Japan for hosting to meet government security standards.
- Phase 2 — Priority Module Migration (Months 4-10): Migrated the highest-risk module first: tax filing. Rebuilt with Angular frontend achieving WCAG 2.1 AA compliance. Implemented .NET Core API layer with backward-compatible database access to enable gradual migration. Load tested to support 5,000+ concurrent users.
- Phase 3 — Remaining Modules (Months 10-16): Systematically migrated permit applications, resident registrations, and facility reservations. Each module went through UAT with actual municipal employees. Implemented a unified design system ensuring consistent, accessible UX across all services.
- Phase 4 — Cutover & Support (Months 16-20): Phased cutover of each module with rollback capability. Comprehensive staff training for 200+ municipal employees. Established 24/7 monitoring and a maintenance support contract. Created detailed system documentation and knowledge transfer to the municipal IT team.
System Architecture
Technology Stack
Results & Impact
The modernized portal achieved 99.95% uptime during the first tax filing season post-migration — compared to 92% the previous year. The system handled a peak of 4,800 concurrent users without degradation. Citizen complaints about the online portal dropped by 50%, and the percentage of citizens filing taxes online increased from 35% to 58%. The WCAG 2.1 AA certification was completed ahead of schedule, making the municipality one of the first in the prefecture to achieve full compliance. Infrastructure costs decreased by 40% by moving from on-premise Windows Server licenses to Azure Government Cloud's consumption-based pricing. The municipality has since contracted BCT Global for Phase 2: adding LINE and MyNumber integration for citizen notifications.
"Government IT modernization is uniquely challenging — the stakes are high because citizens depend on these services, and the procurement process adds layers of complexity. BCT Global's on-site engineers understood our workflows at a level that surprised us. Their Japanese language skills meant they could interview our staff directly, without the translation overhead that usually slows government IT projects. The result was a system built by people who truly understood how municipal government works."
Director of Information Technology Japanese Municipal Government — Population 300,000+