Start with the workflow
A marketplace transaction connects participants, an order, completion conditions, and possible exceptions. Define those responsibilities before choosing how systems should communicate.
Keep the concepts separate
A payment attempt, an order status, and a payout outcome describe different things. A clear model avoids treating a change in one as proof that every related step has finished.
Plan for asynchronous events
Some operations finish later or return through a separate event. Design the surrounding workflow so that it can represent an uncertain or pending state without inventing an outcome.
Explore the underlying concepts.
For more technical context, read AWS: Event-driven architecture ↗. This link is a reference, not a statement of partnership or integration. This introduction is not a complete implementation guide or advice about regulated financial services.