DynamoDb write and fetch are too slow

I am using Dynamodb in one of my Springboot application for the first time and noticing very slow response time.

My table structure is like below -

itemid - A unique key for each record, is made as primary partition key without any sort key.
Around 10 other attributes including 2 of attributes of GSI (item_category(PK), item_date(SK)).

It's taking ~30 minutes to persist ~7k records and approximately a minute to fetch same records, which is too high for my scenario. I was under the impression that we can persist this many records in seconds in DynamoDB. Is my understanding is wrong or is my table is not correct?

DynamoDB table is created with default read/write capacity units(1-10) with auto scaling enabled.

How to improve read/write speed of dynamodb transactions?

Update:

Code which writes to Dynamo table -

public List<MyItems> saveTransactions(List<MyItems> dynamoItems) {
    DynamoDbTable<MyItems> dynamoDbTable = dynamoDbEnhancedClient.table(tableName, TableSchema.fromBean(MyItems.class));
    WriteBatch.Builder<MyItems> dynamoItemsBuilder = WriteBatch.builder(MyItems.class).mappedTableResource(dynamoDbTable);
    for (MyItems transactions : dynamoItems) {
        dynamoItemsBuilder.addPutItem(builder -> builder.item(transactions));
    }
    BatchWriteResult batchWriteResult = dynamoDbEnhancedClient.batchWriteItem(BatchWriteItemEnhancedRequest.builder().writeBatches(dynamoItemsBuilder.build()).build());
    return batchWriteResult.unprocessedPutItemsForTable(dynamoDbTable);
}

Code which reads from Dynamo table -

 public Optional<List<MyItems>> fetchTransactions(String itemCategory, String itemDate) {
    DynamoDbTable<MyItems> userTable = dynamo.table(tableName, TableSchema.fromBean(MyItems.class));
    DynamoDbIndex<MyItems> gsiIndex = userTable.index("GSI_INDEX");
    QueryConditional q = QueryConditional.keyEqualTo(Key.builder().partitionValue(itemCategory).sortValue(itemDate).build());
    Iterator<Page<MyItems>> result = gsiIndex.query(q).iterator();
    List<MyItems> poslogTransactionsList = new ArrayList<>();
    while (result.hasNext()) {
        poslogTransactionsList.addAll(result.next().items());
    }
    return Optional.of(poslogTransactionsList);
}

Bean class -

@Data
@NoArgsConstructor
@DynamoDbBean
public class MyItems {
    @EqualsAndHashCode.Include
    @Getter(AccessLevel.NONE)
    String itemId;
    @Getter(AccessLevel.NONE)
    String itemCategory;
    @Getter(AccessLevel.NONE)
    String itemDate;
    String amount;
    String itemNumber;

    @DynamoDbPartitionKey
    public String getItemId() {
        return itemId;
    }
    @DynamoDbSecondaryPartitionKey(indexNames = "GSI_INDEX")
    public String getItemCategory() {
        return itemCategory;}

    @DynamoDbSecondarySortKey(indexNames = "GSI_INDEX")
    public String getItemDate() {
        return itemDate;}}

Here above piece of code runs based on message received from kafka consumer and each time List<MyItems> can contain 10 or less items. To persist these 10 records(with unique itemid's) also it's taking ~300milliseconds. Is something wrong with the code or table structure?

You’re telling DynamoDB you want 1 read and write per second, so that’s what you’re getting. Yes, you let it auto scale up to 10 but it takes a few minutes to see the traffic and grow step by step up to 10.

Easiest at this scale (and assuming long periods of zero traffic) is set the table to on-demand per-request pricing and you’ll have an extremely fast database.