How To Bring Order to the Logging of Product Events

Okko developed a formal description (schema) of the events that should be logged. From this description, they generated event models for each platform (TypeScript/Kotlin/Swift), documentation and DDL for Impala and ClickHouse. From this, all the discrepancies in field names and types immediately came to light. Then more complex descriptions were added to schemas: enum, nested objects, dependencies between fields. This way they got more guarantees that clients log everything correctly. Based on this, they were able to revise and simplify the events themselves. They reduced the 16 different types of events to a single universal one. The coverage of new features with logs ceased to require the elaboration of analysts and a long implementation on the clients.