The text discusses deadlocks in database transactions, specifically in Postgres, and how to identify and resolve them. Deadlocks occur when two or more processes wait for each other to release a lock, preventing progress. To fix a deadlock, the first solution is to redesign transactions to operate in a consistent order, as deadlocks are often indications of poorly structured logic. Alternative approaches include introducing explicit locks, decreasing the scope of locks, and adding retries with significant jitter. The text also presents a case study of a bulk upsert process that was causing deadlocks due to the random ordering of rows being inserted and the sequential locking mechanism used by Postgres. By understanding the nature of the deadlock and identifying the conflicting processes, developers can design transactions in a consistent order or use alternative approaches to avoid deadlocks.