Provide an interesting problem you solved at your previous job.

At my previous job, one of the interesting tasks was to optimize the database for a high-load web application with millions of users. The main problem was that as the number of requests increased, the response time significantly grew due to locking and inefficient indexes.

To solve this problem, I conducted a detailed analysis of the query profile, identified bottlenecks, and proposed the following measures:

• Redesign of the data schema with normalization and denormalization where justified.
• Creation of composite and covering indexes to speed up queries.
• Implementation of table partitioning to distribute the load.
• Configuration of database server parameters for optimal memory and caching usage.
• Use of replication to separate read and write operations.

As a result, the response time decreased by 3-4 times, and the system became resilient to peak loads.