diff --git a/hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/JsonKinesisSource.java b/hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/JsonKinesisSource.java
index 7ad947830097b..3a297467c82e5 100644
--- a/hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/JsonKinesisSource.java
+++ b/hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/JsonKinesisSource.java
@@ -143,12 +143,12 @@ protected JavaRDD<String> toBatch(KinesisOffsetGen.KinesisShardRange[] shardRang
               KinesisSource.ShardRecordIterator recordIt = KinesisSource.readShardRecords(
                   client, readConfig.getStreamName(), range, readConfig.getStartingPosition(),
                   readConfig.getMaxRecordsPerRequest(), readConfig.getIntervalMilliSeconds(),
-                  readConfig.getMaxRecordsPerShard(), readConfig.isEnableDeaggregation(),
+                  readConfig.getMaxRecordsPerShard(), readConfig.isDeaggregationEnabled(),
                   readConfig.getRetryInitialIntervalMs(), readConfig.getRetryMaxIntervalMs(),
                   readConfig.getThrottleTimeoutMs());
 
               String shardId = range.getShardId();
-              boolean addMetaFields = readConfig.isShouldAddMetaFields();
+              boolean addMetaFields = readConfig.isMetaFieldsEnabled();
               List<String> jsonRecords = new ArrayList<>();
               long numNull = 0;
               java.time.Instant lastArrivalTimestamp = null;
diff --git a/hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/KinesisSource.java b/hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/KinesisSource.java
index 919bac890581f..a5ec35994d8e0 100644
--- a/hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/KinesisSource.java
+++ b/hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/KinesisSource.java
@@ -237,7 +237,7 @@ private void fetchNextPage() {
           response = client.getRecords(
               GetRecordsRequest.builder()
                   .shardIterator(shardIteratorStr)
-                  .limit(Math.min(currentMaxRecords, (int) (maxTotalRecords - totalConsumed)))
+                  .limit(Math.min(currentMaxRecords, Math.toIntExact(maxTotalRecords - totalConsumed)))
                   .build());
           lastSuccessTimeMs = System.currentTimeMillis();
           break;
@@ -290,7 +290,9 @@ private void fetchNextPage() {
 
       // Process records first (done above), then decide whether to stop.
       // millisBehindLatest can be 0 in LocalStack even when the response contained records.
-      if (response.millisBehindLatest() == 0) {
+      // It is documented as nullable on AWS SDK responses, so guard against NPE on auto-unbox.
+      Long millisBehind = response.millisBehindLatest();
+      if (millisBehind != null && millisBehind == 0) {
         fetchingDone = true;
       }
       if (shardIteratorStr == null) {
diff --git a/hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/helpers/KinesisOffsetGen.java b/hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/helpers/KinesisOffsetGen.java
index b0f1779a50be2..27d160c3de0fc 100644
--- a/hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/helpers/KinesisOffsetGen.java
+++ b/hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/helpers/KinesisOffsetGen.java
@@ -42,6 +42,7 @@
 import software.amazon.awssdk.services.kinesis.model.ResourceNotFoundException;
 import software.amazon.awssdk.services.kinesis.model.Shard;
 
+import java.math.BigInteger;
 import java.net.URI;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -162,6 +163,17 @@ public static Pair<Option<String>, Option<String>> parseCheckpointValue(String v
           Option.ofNullable(getEndSeqFromValue(value)));
     }
 
+    /**
+     * Compares two Kinesis sequence numbers numerically.
+     * Kinesis sequence numbers are 128-bit integers represented as decimal strings whose lengths
+     * can vary, so lexicographic {@link String#compareTo} is not correct for numeric ordering.
+     *
+     * @return negative if a &lt; b, zero if equal, positive if a &gt; b
+     */
+    public static int compareSequenceNumbers(String a, String b) {
+      return new BigInteger(a).compareTo(new BigInteger(b));
+    }
+
     /**
      * Build checkpoint value without arrival time: "lastSeq" or "lastSeq|endSeq".
      */
@@ -262,7 +274,7 @@ public boolean hasUnreadRecords(boolean useLatestWhenNoCheckpoint) {
         return !useLatestWhenNoCheckpoint;
       }
       // CASE 3: Closed shard: lastSeq >= endSeq means fully consumed
-      if (lastSeq.compareTo(endSeq) >= 0) {
+      if (CheckpointUtils.compareSequenceNumbers(lastSeq, endSeq) >= 0) {
         return false;
       }
       // CASE 4: lastSeq < endSeq: may have unread records
@@ -459,9 +471,11 @@ void checkDataLossOnExpiredShards(List<String> expiredShardIds, Map<String, Stri
       Option<String> lastSeqOpt = seqs.getLeft();
       Option<String> endSeqOpt = seqs.getRight();
       // endSeq absent = was open shard; conservatively assume not fully consumed.
-      // endSeq present: fully consumed iff lastSeq >= endSeq.
+      // endSeq present with non-empty lastSeq: fully consumed iff lastSeq >= endSeq.
+      // Empty lastSeq (e.g. "|endSeq" checkpoint) is treated as not consumed.
       boolean fullyConsumed = endSeqOpt.isPresent()
-          && lastSeqOpt.map(last -> last.compareTo(endSeqOpt.get()) >= 0).orElse(false);
+          && lastSeqOpt.map(last -> !last.isEmpty()
+              && CheckpointUtils.compareSequenceNumbers(last, endSeqOpt.get()) >= 0).orElse(false);
       if (fullyConsumed) {
         log.info("Expired shard {} was fully consumed (lastSeq >= endSeq); pruning from checkpoint", shardId);
       } else {
@@ -495,7 +509,7 @@ void checkDataLossOnAvailableShards(List<Shard> shards, Map<String, String> from
         continue;
       }
       // lastSeq < shardStartSeq: records between the checkpoint and the trim horizon were dropped.
-      if (lastSeq.compareTo(shardStartSeq) < 0) {
+      if (CheckpointUtils.compareSequenceNumbers(lastSeq, shardStartSeq) < 0) {
         reportDataLoss("Shard " + shardId + " checkpoint lastSeq=" + lastSeq
             + " is before the shard's earliest available sequence number " + shardStartSeq
             + ". Records may have been trimmed due to retention expiry (data loss).");
diff --git a/hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/helpers/KinesisReadConfig.java b/hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/helpers/KinesisReadConfig.java
index e6bf12c5f8b1d..7fe53f24d0f93 100644
--- a/hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/helpers/KinesisReadConfig.java
+++ b/hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/helpers/KinesisReadConfig.java
@@ -41,8 +41,8 @@ public class KinesisReadConfig implements Serializable {
   private final String accessKey; // null if not set
   private final String secretKey; // null if not set
   private final KinesisSourceConfig.KinesisStartingPositionStrategy startingPosition;
-  private final boolean shouldAddMetaFields;
-  private final boolean enableDeaggregation;
+  private final boolean metaFieldsEnabled;
+  private final boolean deaggregationEnabled;
   private final int maxRecordsPerRequest;
   private final long intervalMilliSeconds;
   private final long maxRecordsPerShard;