EXM is an eventual-consistent system. Unlike strong consistency where changes are guaranteed as soon as a modification transaction (such as a Write Operation) takes place, EXM guarantees changes will be made but it is not instant.
Since EXM is an eventual-consistent system, some APIs might be called multiple times before finality is reached, or some APIs might have unknown values.
EXM behaves as a deterministic lambda function that persist its request and responses throughout history by using Blockchain technology, specifically Arweave. These lambda functions are essentially stateful and can behave as a sort of database. The state of this database is affected by eventual consistency as described above. Any EXM application developed to keep a truly stateful result must be aware of the aforementioned concepts.