Tell us about the event bus at Avito — did you work on an existing one or rewrite it from scratch?

I worked with an existing event bus at Avito. It was built on Kafka and provided asynchronous communication between services.

Key points:

• The bus allowed scaling of event processing and ensured reliable delivery.
• We focused on optimizing consumption and monitoring delays.
• In some cases, we rewrote individual components to improve performance and ease of integration.

Rewriting the bus from scratch is usually expensive and risky, so the existing architecture is often developed and adapted to new requirements.