Pros of Flowable Engine

• Lighter weight and more modular architecture
• Better support for cloud-native deployments
• More flexible and extensible API design

Cons of Flowable Engine

• Smaller community and ecosystem compared to Camunda
• Less comprehensive documentation and learning resources
• Fewer out-of-the-box integrations with third-party tools

Code Comparison

Flowable Engine:

ProcessEngine processEngine = ProcessEngines.getDefaultProcessEngine();
RuntimeService runtimeService = processEngine.getRuntimeService();
ProcessInstance processInstance = runtimeService.startProcessInstanceByKey("myProcess");

Camunda BPM Platform:

ProcessEngine processEngine = ProcessEngineConfiguration.createStandaloneInMemProcessEngineConfiguration().buildProcessEngine();
RuntimeService runtimeService = processEngine.getRuntimeService();
ProcessInstance processInstance = runtimeService.startProcessInstanceByKey("myProcess");

Both examples demonstrate starting a process instance, but Flowable's API is slightly more concise. However, the overall structure and approach are similar, making it relatively easy for developers to switch between the two platforms if needed.

Pros of Activiti

• Lightweight and more flexible architecture
• Easier integration with Spring Boot applications
• More active community and frequent updates

Cons of Activiti

• Less comprehensive documentation compared to Camunda
• Fewer out-of-the-box features and tools
• Limited enterprise support options

Code Comparison

Activiti process definition:

<process id="myProcess" name="My Process">
  <startEvent id="start" />
  <userTask id="userTask" name="User Task" />
  <endEvent id="end" />
  <sequenceFlow sourceRef="start" targetRef="userTask" />
  <sequenceFlow sourceRef="userTask" targetRef="end" />
</process>

Camunda process definition:

<bpmn:process id="myProcess" name="My Process" isExecutable="true">
  <bpmn:startEvent id="start" />
  <bpmn:userTask id="userTask" name="User Task" />
  <bpmn:endEvent id="end" />
  <bpmn:sequenceFlow sourceRef="start" targetRef="userTask" />
  <bpmn:sequenceFlow sourceRef="userTask" targetRef="end" />
</bpmn:process>

Both Activiti and Camunda use similar BPMN 2.0 XML syntax for process definitions. The main difference is the namespace prefix, with Camunda using bpmn: for BPMN elements. Camunda also includes the isExecutable="true" attribute by default, which is optional in Activiti.

Pros of Airflow

• More extensive ecosystem with a wide range of integrators and operators
• Better suited for data pipeline orchestration and ETL workflows
• Stronger support for Python-based workflows and data science tasks

Cons of Airflow

• Steeper learning curve, especially for non-technical users
• Less focus on business process modeling and human task management
• May require more infrastructure setup and maintenance

Code Comparison

Airflow DAG definition:

from airflow import DAG
from airflow.operators.python_operator import PythonOperator
from datetime import datetime

def my_task():
    print("Hello from Airflow!")

dag = DAG('simple_dag', start_date=datetime(2023, 1, 1))
task = PythonOperator(task_id='my_task', python_callable=my_task, dag=dag)

Camunda BPMN process definition:

<bpmn:process id="Process_1" isExecutable="true">
  <bpmn:startEvent id="StartEvent_1" />
  <bpmn:task id="Task_1" name="My Task">
    <bpmn:script>print("Hello from Camunda!");</bpmn:script>
  </bpmn:task>
  <bpmn:endEvent id="EndEvent_1" />
  <bpmn:sequenceFlow id="Flow_1" sourceRef="StartEvent_1" targetRef="Task_1" />
  <bpmn:sequenceFlow id="Flow_2" sourceRef="Task_1" targetRef="EndEvent_1" />
</bpmn:process>