Kafka Streams alternative — Kafka Streams vs Skippr
Kafka Streams is Apache Kafka's JVM library for stream processing inside your application. Current Kafka is 4.4.0 (22 Oct 2026). You add kafka-streams, write a topology (DSL or Processor API), and your service becomes the consumer group. State lives in local stores backed by changelog topics. Interactive queries (IQv2) read those stores. 4.4.0 adds transactional state stores (enable.transactional.statestores, default off, KIP-892), broker-side Streams group assignors (KIP-1357), topology description on the group (KIP-1331), and headers-aware IQv2 queries (KIP-1356). I/O is Kafka topics. There is no Iceberg sink in Streams. The Iceberg path is still the Kafka Connect Iceberg connector (Iceberg 1.12.0) or Tableflow on Confluent Cloud. CDC starts before Streams: Debezium or a producer writes the topic. There is no licence fee for Apache Kafka. You pay brokers, changelogs, disks, and the JVM. Confluent Cloud also bills a Kafka Streams line per eCKU/CKU-hour on clusters with a connected Streams app. This is not a Streamhouse. There is no Iceberg ∪ WAL.
Skippr is an open Streamhouse you run as one Rust binary. Write skippr.yml (or the same thing in Python), discover, sync. You query live state over Iceberg ∪ WAL, and the history is ordinary Iceberg in your bucket. No changelog topic. ELT into a warehouse is one path, not the product.
| Feature | Skippr | Kafka Streams |
|---|---|---|
| Deploy | Single Rust binary, your VPC or on-prem | JAR in your app, plus a Kafka cluster |
| Schema | In-stream evolution, sibling columns | Serdes plus Schema Registry if you add it |
| Storage | Open Iceberg on Parquet you own | Changelog-backed state stores. Iceberg is Connect or Tableflow after |
| CDC | Log-based; fails closed if the dest cannot honour | Reads CDC already on a topic. Capture is Debezium or a producer |
| Query | skipprd query on Iceberg ∪ WAL; history in any Iceberg engine | Interactive queries on local stores. Lake is a later sink |
| Pricing | Free self-hosted engine | Apache-2.0. Pay Kafka. Confluent Cloud adds a Streams eCKU/CKU line. |
What Kafka Streams is good at
Custom stream processing in the same JVM service that already speaks Kafka, without standing up a Flink or ksqlDB cluster. That is the product. Processor API, punctuators, and now transactional stores are why app teams still embed it. If the job is "this topology in our service," that is a real product.
Where the job is wider
Kafka Streams is a library over Kafka. It is not a Streamhouse. There is no Iceberg ∪ WAL. There is no skipprd query on in-flight Iceberg rows. Postgres is not a Streams source. Iceberg starts after: Connect or Tableflow. Restore time on a large changelog is still the restart tax unless you turn on transactional stores and accept the new buffer.
The cluster is the ops. Brokers, partitions as the scale cap, rebalances, state dirs. Skippr will not run a Streams topology. Skippr also will not replace a Kafka bus. ksqlDB is SQL on the same engine (separate page).
If the job is "Kafka Streams we already embed," Streams is the narrower tool. If the job is live SQL on Iceberg you run, the library was never that.
Getting started
Install skipprd from the install guide, or pip install skippr. The three tabs write the same skippr.yml. Then discover, sync, and query.
skippr:
workspace: analytics
skipprd_el_storage_mode: local
pipelines:
orders:
data_source: data_sources.app_db
data_sink: data_sinks.lake
data_sources:
app_db:
Postgres:
host: db.internal
user: skippr_reader
password: ${APP_DB_PASSWORD}
database: app
tables: [orders, customers]
cdc_mode: snapshot_then_cdc
data_sinks:
lake:
AthenaIceberg:
warehouse: s3://my-iceberg-warehouse/
glue_database_name: analytics
athena_workgroup_name: primary
athena_results_s3_bucket: my-athena-results
region: us-east-1
schema_sink: schema_sinks.lake_schema
schema_sinks:
lake_schema:
AthenaIceberg:
warehouse: s3://my-iceberg-warehouse/
glue_database_name: analytics
athena_workgroup_name: primary
athena_results_s3_bucket: my-athena-results
region: us-east-1skipprd --workspace analytics --storage-mode local connect data-source postgres \
--pipeline orders \
--name app_db \
--host db.internal \
--user skippr_reader \
--password '${APP_DB_PASSWORD}' \
--database app \
--tables orders \
--tables customers \
--cdc-mode snapshot_then_cdc
skipprd connect data-sink athenaiceberg \
--pipeline orders \
--name lake \
--warehouse s3://my-iceberg-warehouse/ \
--glue-database-name analytics \
--athena-workgroup-name primary \
--athena-results-s3-bucket my-athena-results \
--region us-east-1
skipprd connect schema-sink athenaiceberg \
--pipeline orders \
--name lake_schemafrom skippr import (
Config,
DataSinkAthenaIceberg,
DataSourcePostgres,
DataSourcePostgresSourceCdcMode,
EnvRef,
LocalStorage,
Pipeline,
)
cfg = Config().workspace("analytics").storage(LocalStorage())
app_db = cfg.data_source(
"app_db",
DataSourcePostgres(
host="db.internal",
user="skippr_reader",
password=EnvRef("APP_DB_PASSWORD"),
database="app",
tables=["orders", "customers"],
cdc_mode=DataSourcePostgresSourceCdcMode.SNAPSHOTTHENCDC,
),
)
lake = cfg.data_sink(
"lake",
DataSinkAthenaIceberg(
warehouse="s3://my-iceberg-warehouse/",
glue_database_name="analytics",
athena_workgroup_name="primary",
athena_results_s3_bucket="my-athena-results",
region="us-east-1",
),
schema_sink="lake_schema",
)
cfg.pipeline("orders", Pipeline(data_source=app_db, data_sink=lake))
cfg.save("skippr.yml")export APP_DB_PASSWORD='your-postgres-password'
skipprd discover --pipeline orders
skipprd sync --pipeline orders --once
skipprd query "SELECT count(*) FROM analytics.orders"Which to choose
Choose Kafka Streams if you want a JVM topology inside a service that already speaks Kafka, and the next topic is the job.
Choose Skippr if you want one binary, live SQL on Iceberg ∪ WAL, and files that stay yours. Skippr will not run a Streams application.
Install from Install. Connector and query reference live in Developer Docs. For optional onboarding in your VPC, Enterprise Jumpstart or Contact.
