Error: dynamodb mapper save not persisting

DynamoDBMapper.save appearing not to persist is a symptom, not a specific endpoint error. Verify the call completed, the effective table name and client environment, and the exact key used for the follow-up read.

1. Do not swallow mapping, conditional-write or service exceptions. If using asynchronous code, wait for completion.
2. Check mapper table-name overrides, generated keys, Region, credentials and any local endpoint override.
3. Verify getter/setter annotations and converter output. Ignored or unmapped properties are not written.
4. Read the base table by its complete primary key with a strongly consistent read. GSI queries are eventually consistent.

Java SDK 1.x DynamoDBMapper is legacy. The v2 Enhanced Client equivalent is a mapped table and putItem:

// Person is a @DynamoDbBean with an annotated partition-key getter.
DynamoDbClient client = DynamoDbClient.builder()
    .region(Region.US_EAST_1).build();
DynamoDbEnhancedClient enhanced = DynamoDbEnhancedClient.builder()
    .dynamoDbClient(client).build();
DynamoDbTable<Person> table = enhanced.table(
    "People", TableSchema.fromBean(Person.class));
table.putItem(person);

Import DynamoDbClient and Region from software.amazon.awssdk and the mapping classes from enhanced.dynamodb. The variable person is the populated bean to save. putItem replaces the item; choose updateItem deliberately when partial-update semantics are needed. For AWS tables, a custom endpoint is normally unnecessary.

See Java mapping examples and AWS documentation.