Saving states, retries, deduplication

Saving states, retries, deduplication

In modern API integrations, it is important not only to send or receive data, but to ensure that all events are processed once, correctly and reliably. We implement the architecture by saving intermediate states, re-delivery mechanisms and message deduplication to eliminate losses and duplicates in working with external services and queues.

This is especially important when working with transactions, payment gateways, webhook events and background tasks, where multiplicity and completeness are critical.

What is implemented

Mechanism	Purpose and Benefits
Save state	Ability to continue from the fault location or monitor processing progress
Automatic retries	Retry in case of error, with exponential delay
Deduplication	Protection against double processing of identical requests or events
Event IDs	Support for 'event _ id', 'message _ id', hash tracking
Deferred Tasks	Try again later if external service is temporarily unavailable

How does it work

1. An incoming request or event receives a unique identifier
2. The entry is added to the processing log (DB, Redis or Kafka)
3. In case of error, the task is queued for retry (with limit and control)
4. If the same event is received again, the system checks its ID and rejects the duplicate
5. All event history and processing status available for audit

API and Platform Benefits

Eliminates duplicates for network failures, repeated webhooks, or client errors
Reliable delivery even for temporary problems
Minimizing load on external APIs and databases
Accurate logging, auditing, and recovery
Scalability and flexibility for different scenarios (payments, bonuses, events)

Where especially important

Financial transactions, billing, deposits
Gaming events: bets, wins, settlements
Integrations with webhooks and slow APIs
Heavy load architectures with background tasks

States, retries, and deduplication are what make API integrations sustainable. We design logic so that even in conditions of failures and unstable connections, your data is safe, and processes are complete and without duplicates.