Keep your Kafka clients.
Measure a different broker.

Properties props = new Properties();
props.put("bootstrap.servers", "localhost:9092");
props.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");
props.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");

Producer<String, String> producer = new KafkaProducer<>(props);
producer.send(new ProducerRecord<>("quickstart-events", "user-1", "Hello Krabka from Java!"));

from confluent_kafka import Producer

producer = Producer({"bootstrap.servers": "localhost:9092"})

producer.produce(
    "quickstart-events",
    key="user-1",
    value="Hello Krabka from Python!",
)

cl, err := kgo.NewClient(kgo.SeedBrokers("localhost:9092"))

rec := &kgo.Record{Topic: "quickstart-events", Key: []byte("user-1"), Value: []byte("Hello Krabka from Go!")}
if err := cl.ProduceSync(context.Background(), rec).FirstErr(); err != nil { panic(err) }

const { Kafka } = require('kafkajs');

const kafka = new Kafka({ clientId: 'quickstart', brokers: ['localhost:9092'] });
const producer = kafka.producer();
await producer.connect();

await producer.send({
    topic: 'quickstart-events',
    messages: [{ key: 'user-1', value: 'Hello Krabka from KafkaJS!' }],
});

kafka-console-producer.sh --bootstrap-server localhost:9092 --topic quickstart-events