BigCommerce API rate limits, when do they actually bite?

Rate limits become material when simultaneous integrations consume the available quota or cannot recover within the required time. BigCommerce REST quotas are shared by apps on a store and vary by plan and resource; they are not one universal requests-per-second allowance. Measure catalog, inventory and order-sync demand together. Use batching and appropriate retry behavior, then test backlog recovery. Request the applicable limits for the proposed contract rather than copying an old plan table.

Official references: BigCommerce REST API rate limits.