High-Availability Modernization and Regional Redundancy for a Retail Platform

Executive Snapshot

A leading retail enterprise operating across North America relied on a single-region GCP deployment in US-Central (Iowa). Regional outages caused full platform shutdowns, impacting both internal teams and thousands of end-customers. Downtime resulted in direct revenue loss and declining trust.

Transcloud designed a multi-region, high-availability architecture across Montreal and Iowa, giving the company full operational control over failover decisions, improving resilience, and eliminating single-region dependency.

Key Outcomes

• Availability improved from 99.5% → 99.95%
  
• RTO < 15 minutes, RPO near-zero
  
• Zero data loss during failover testing
  
• Eliminated single-region failure risks
  
• Reduced outage-related financial losses to near-zero
  
• Delivered runbooks enabling ops team to do failover execution
  
• Seamless muli-regional implementation to Montreal
  

Challenge

The retail company depended entirely on a single GCP region (Iowa). Any regional outage led to complete disruption of customer-facing retail applications, order management systems, and internal business tools. With no disaster recovery architecture and a fully concentrated risk footprint, the business lacked resilience and had no ability to operate during GCP regional incidents.

Key Challenges

• Full production downtime during US-Central outages
  
• No disaster recovery capability
  
• Single geographic point of failure for all retail operations
  
• Inability to route traffic or switch workloads during incidents
  
• Risk of customer churn due to service unavailability
  
• Data layer not protected for regional disruptions
  

Solution

Transcloud designed and deployed a dual-region active–passive architecture tailored for the retail industry, ensuring high uptime and consistent customer experience even during regional disruptions. We implemented fully duplicated App Engine environments across Montreal as the primary region and Iowa as the failover, while enabling multi-region operation for Cloud Tasks, Cloud Scheduler, and Cloud Functions to maintain workflow continuity. Cloud Load Balancing was configured to support controlled traffic redirection during failover events, and Datastore nam5 dual-region storage ensured synchronous data replication with high durability. To strengthen operational readiness, Transcloud built manual failover and failback playbooks, delivered detailed runbooks for region transitions, and executed three structured failover test cycles to refine procedures. Additionally, we upgraded the landing zones and GCP foundation to support multi-region deployments. As part of the regional strategy, Montreal was established as the primary production region to reduce outage exposure, while Iowa was positioned as the dedicated failover environment, with nam5 Datastore ensuring a consistent data state across both regions.

Tools & Technologies

• App Engine – Retail application hosting
  
• Cloud Load Balancing – Regional routing and failover control
  
• Cloud Tasks / Cloud Scheduler – Background operations and scheduled jobs
  
• Cloud Functions – Event-driven compute for retail workflows
  
• Datastore (nam5) – Multi-region NoSQL with synchronous replication
  
• GCP Landing Zones – Standardized deployments for HA architecture
  
• Architecture Patterns: Active–Passive, manual failover, multi-region replication
  

Impact

The multi-region setup significantly improved the client’s reliability, performance, and operational readiness, ensuring their retail platform could withstand regional disruptions without affecting customer experience.

Key Impact

• Achieved < 15-minute RTO and near-zero RPO across all three failover tests
  
• Reduced MTTR from hours to minutes
  
• Minimized revenue loss during outages to near-zero
  
• Ensured 100% data consistency during all failover and failback cycles
  
• Maintained session persistence across regional transitions
  
• Validated < 30ms latency difference for cross-region operations
  
• Enabled a seamless production shift to Montreal without any code changes
  
• Implemented multi-region replication without performance degradation
  
• Delivered runbooks and operational playbooks enabling the client’s teams to manage transitions independently
  

Why They Partnered With Transcloud

• Expertise delivering multi-region GCP architectures for large enterprises
  
• Ability to design business-controlled failover instead of auto-triggered events
  
• Strong foundation engineering experience for scalable, HA retail systems
  
• Proven track record executing zero-downtime, multi-region transitions