Zillow processes over 100 million personalized notifications each day through a unified orchestration platform running on AWS Step Functions Express Workflows, replacing fragmented campaign microservices and reducing duplicated engineering overhead.
- Centralized orchestration reduces duplicated workflows and operational costs
- Serverless Step Functions Express enables scalable, reliable, low-cost execution
- Reusable content modules accelerate campaign development and consistency
Infrastructure signal
Zillow transitioned from multiple independent campaign generators to a single orchestration platform built on AWS Step Functions Express Workflows. This approach leverages short-lived, high-volume workflows that handle event intake, data enrichment, rule application, content assembly, and delivery consistently at scale. Using a managed, serverless workflow engine eliminated the need to maintain additional infrastructure and reduced operational overhead.
This architectural change optimizes cloud cost by using ephemeral workflows and reduces complexity in monitoring and scaling. The unified system supports over 100 million daily executions, demonstrating the viability of managed, event-driven orchestration for high-throughput communication systems without provisioning dedicated workflow infrastructure.
Developer impact
Standardizing campaign logic into configurable workflows and reusable universal content modules has significantly improved developer agility. Previously, more than 10 microservices each implemented their own business rules, workflows, and data models, which slowed release velocity and increased operational risk due to inconsistency. The new platform allows product teams to launch and iterate campaigns without redundant engineering effort.
The declarative configuration model reduces cognitive load for developers, enabling faster testing and launching of experiments. Additionally, the modular content library supports schema-driven generation that facilitates AI-assisted tooling integration, further accelerating feature development and ensuring consistent messaging experiences across campaigns.
What teams should watch
Teams responsible for large-scale notification systems, campaign orchestration, or content generation should evaluate the benefits of consolidating fragmented services into a serverless, configuration-driven platform. This can significantly cut cloud costs by optimizing resource use and reduce operational complexity by using managed workflow orchestration.
Observability processes will shift towards monitoring ephemeral workflow executions and reusable modules rather than discrete microservices, requiring updates to logging, tracing, and alerting strategies. Database and API integration patterns will need to support dynamic data enrichment workflows orchestrated by Step Functions, ensuring reliable and timely notification assembly and delivery.