Why Some Teams Are Moving from Kafka to Pulsar
(And Why Others Aren’t)

Why Some Teams Are Moving from Kafka to Pulsar (And Why Others Aren’t)

Apache Pulsar has gained traction in the event streaming world—particularly among teams that have outgrown some of Apache Kafka’s limitations. But while some organizations are migrating to Pulsar, many others are sticking with Kafka, often for very good reasons.

In this post, we’ll break down what’s driving adoption of Pulsar, what’s holding others back, and how we help clients make the right decision based on real-world needs.

At Dattell, we support both Pulsar and Kafka, so our comparison is grounded in hands-on experience with each—giving you a fair and balanced perspective.

Why Teams Are Switching to Pulsar

Let’s start with the five reasons that keep coming up for clients when they choose to adopt Pulsar.

Built-in Multi-Tenancy and Isolation

Pulsar was designed from day one to support multiple tenants via namespaces, quotas, and access control. This is a major win for SaaS platforms and enterprises with complex organizational boundaries.

Kafka Limitation

Kafka requires additional tooling or broker-level workarounds for multi-tenancy, and resource isolation can be tricky.

Separation of Storage and Compute

Pulsar decouples brokers from storage by offloading messages to Apache BookKeeper. This enables horizontal scaling and more efficient disk usage—especially in cloud environments.

Kafka Limitation

Kafka tightly couples brokers and storage, which can make scaling and operational management more rigid.

Built-in Geo-Replication

Pulsar offers native geo-replication out of the box, making it easier to build cross-region streaming systems without custom tooling.

Kafka Limitation

Kafka requires MirrorMaker 2.0 (or Confluent Replicator) and extensive tuning to achieve similar functionality.

Unified Pub/Sub + Queue Semantics

Pulsar supports both publish-subscribe and message queue patterns (shared, failover, key_shared). This flexibility lets teams consolidate workloads that might otherwise be split across Kafka and RabbitMQ.

Kafka Limitation

Kafka is fundamentally pub/sub and less flexible for task queues or per-consumer message routing.

Tiered Storage for Infinite Retention

Pulsar enables long-term retention by offloading data to object stores like S3, which supports compliance use cases and data lakes.

Kafka Limitation

Long retention requires provisioning expensive local disk or Kafka Tiered Storage via Confluent Platform.

Why Many Teams Still Choose Kafka

With all of the Kafka limitations above, none are true limitations. Rather they just require extra tuning or introduce some rigidity. This is why many clients continue to invest in their Kafka architecture. Let’s dig into a few reasons why.

Maturity and Ecosystem

Kafka has a massive ecosystem with broad tooling support, deep documentation, and enterprise-grade integrations like Kafka Connect, KSQL, and Confluent Cloud. And if you’re comparing Confluent and Apache Kafka we’ve got your covered with the comparison.

Kafka Advantage

Fewer surprises, better community support, more comprehensive documentation, and more mature connectors.

Operational Simplicity at Scale

While Pulsar offers strong architecture, it introduces complexity with BookKeeper, ZooKeeper, and topic compaction policies.

Kafka Advantage

Kafka can be simpler to operate for many deployments. And can be more stable than Pulsar in certain situations.

Wider Developer Familiarity

Kafka is often the default for streaming architecture. Engineers are more likely to be familiar with Kafka APIs, tuning parameters, and deployment patterns.

Kafka Advantage

Reduced onboarding time and easier hiring.

How We Help Clients Decide

We help clients compare Pulsar vs. Kafka based on:

Workload types (analytics vs. task queue vs. pub/sub)
Latency & throughput requirements
Cost modeling and cloud storage preferences
Team expertise and existing toolchain

In some cases, hybrid architectures make sense—using Kafka for core pipelines and Pulsar for edge workloads or multi-tenant applications.

Need help evaluating or deploying Pulsar or Kafka? Contact us to start a tailored assessment.

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Why Some Teams Are Moving from Kafka to Pulsar (And Why Others Aren’t)