Escaping Vendor Lock-In: Kafka Portability Strategies

Your Kafka deployment works great on Confluent Cloud. Until pricing changes, or you acquire a company running MSK, or compliance requires on-prem in Frankfurt.

"Just change the bootstrap servers" becomes a six-month project.

We thought MSK IAM auth was convenient. Then we needed to migrate to Confluent Cloud. Every service had IAM-specific code. It took 4 months to untangle.

Staff Engineer at a fintech

Where Lock-In Happens

Layer	Portable	Vendor-Specific
Wire protocol	Kafka protocol	Proprietary extensions
Authentication	SASL/SCRAM, mTLS	IAM (MSK), API keys (Confluent)
Authorization	Standard ACLs	RBAC (Confluent), IAM policies (MSK)
Schema Registry	Confluent OSS, Apicurio	Cloud-native registries

The wire protocol is portable. Authentication and authorization are where portability breaks.

Portable Configuration Pattern

Hardcoding bootstrap servers is the fastest path to lock-in:

// LOCKED IN
props.put("bootstrap.servers", "pkc-abc123.confluent.cloud:9092");

Portable alternative:

props.put("bootstrap.servers", System.getenv("KAFKA_BOOTSTRAP_SERVERS"));
props.put("security.protocol", System.getenv("KAFKA_SECURITY_PROTOCOL"));
props.put("sasl.mechanism", System.getenv("KAFKA_SASL_MECHANISM"));
props.put("sasl.jaas.config", System.getenv("KAFKA_SASL_JAAS_CONFIG"));

Same code runs against local Kafka, MSK, Confluent, or Redpanda. Only the environment changes.

Authentication Portability

SASL/SCRAM (Most Portable): Works on self-managed, MSK, Aiven, Instaclustr.

IAM Authentication (MSK Only): This is a lock-in point.

# MSK-SPECIFIC: Won't work anywhere else
sasl.mechanism=AWS_MSK_IAM
sasl.client.callback.handler.class=software.amazon.msk.auth.iam.IAMClientCallbackHandler

Portability strategy: Use SCRAM on MSK instead of IAM if you anticipate migration. MSK supports both.

Tradeoff: IAM gives unified AWS identity. SCRAM gives portability. Pick one.

The Abstraction Layer

Environment variables help with configuration. They don't help when you need to switch clusters without redeploying 47 services.

A gateway layer sits between applications and clusters. Gateway interceptors can handle authentication translation, routing, and policy enforcement across different backends.

Applications (gateway.internal:9092)
           │
           ▼
    Gateway / Proxy
           │
    ┌──────┴──────┐
    ▼             ▼
Primary       Secondary
(Confluent)   (MSK)

Applications connect to one stable endpoint. The proxy routes traffic. Cluster migration becomes a routing change, not a coordinated deployment.

Schema Registry Migration

Schema Registry is often overlooked as a lock-in point. Export schemas regularly:

curl -u $API_KEY:$API_SECRET \
  https://psrc-xxx.confluent.cloud/subjects | jq -r '.[]' | while read subject; do
    curl -u $API_KEY:$API_SECRET \
      "https://psrc-xxx.confluent.cloud/subjects/$subject/versions/latest/schema" \
      > schemas/$subject.avsc
done

Test schema compatibility on target before migration.

Test Your Portability

Can you run your application against a local Kafka cluster with docker-compose? If not, you're more locked in than you think.

Vendor lock-in happens in small increments. Each proprietary convenience adds friction to your eventual migration.

Book a demo to see how Conduktor Gateway provides the abstraction layer for multi-cloud Kafka deployments.