How CQRS Pattern Fixed a Construction App's Weekly Crash Under Peak Load

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A field workforce reporting platform repeatedly crashed every Friday at 4:30 PM when thousands of construction workers simultaneously submitted weekly logs, overwhelming the database with concurrent read and write requests. Engineers redesigned the system using Command Query Responsibility Segregation (CQRS), routing write requests through Azure Service Bus so background workers could process submissions at a steady pace rather than all at once. The change eliminated end-of-week downtime by spreading a five-minute traffic spike across a manageable fifteen-minute processing window. However, the shift to asynchronous processing introduced eventual consistency, causing project managers to see outdated dashboards and prompting frustrated workers to resubmit forms multiple times, generating duplicate records. The team addressed this by adding unique submission IDs to prevent duplicates and displaying a processing status indicator in the UI so users understood their data was being handled.

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ProgrammingDEV Community ·

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ProgrammingDEV Community ·

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ProgrammingDEV Community ·

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