Temporal

AWS Step Functions forces developers to structure orchestration logic inside JSON-based state machines and pay per transition across cloud-managed steps. Temporal shifts that model to durable execution in code, allowing engineers to write long-running business processes as plain Go, TypeScript, Java, or Python functions. By persisting execution history into a self-hosted database rather than a vendor runtime, it preserves ordinary debugging, local unit testing, and full infrastructure portability.

Why Temporal instead of AWS Step Functions

In AWS Step Functions, multi-step logic requires verbose Amazon States Language declarations and glue Lambdas. Developers cannot step through ASL in an IDE debugger, mock dependencies with unit testing tools, or share code libraries across steps easily. Temporal executes workflows as application code through native SDKs. A retry is an idiomatic loop, a multi-day delay is a sleep call, and compensations run as plain catch blocks, keeping orchestration inside your codebase rather than external cloud configuration.

The trade-off is operational responsibility. AWS Step Functions is fully serverless, integrated with IAM, and maintained by AWS. Operating Temporal requires running cluster services—frontend, matching, history, and internal workers—backed by PostgreSQL or Cassandra. For teams running Kubernetes, that operational investment eliminates Step Functions' 256 KB payload limits, removes per-transition pricing, and avoids cloud vendor lock-in.

What it does well

• Workflows as code: developers write orchestration in Go, Java, TypeScript, Python, and .NET, using standard language constructs instead of JSON state machines.
• Deterministic event replay: the server records append-only event histories, reconstructing workflow state across process crashes and deployments.
• Built-in retry policies: activities support exponential backoff and timeouts without custom queue plumbing.
• Heartbeating: workers report progress on long-running tasks, enabling prompt failure detection without waiting for long timeouts.
• Signals and queries: external systems can send signals to alter workflow state or query values synchronously without database polling.
• Local development CLI: a single binary runs locally on macOS, Linux, or Windows with an embedded Web UI and SQLite persistence for fast iteration.