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Oct 27, 2022 | 4 minute read

Elastic Path Leverages Fastly in a Quest for Near Instant API Response Times

written by James Luterek

Time is Money.

In the eCommerce industry that statement has been proven repeatedly. Even small performance improvements can have large impacts on overall revenue.

  • Seventy percent of consumers admit that page speed impacts their willingness to buy from an online retailer. - Unbounce
  • Website conversion rates drop by an average of 4.42% with each additional second of load time. - Portent

With this reality in mind, Elastic Path takes every step possible to improve performance, including leveraging Fastly for edge delivery and intelligent caching.

Elastic Path Commerce Cloud Tech Stack

Elastic Path Commerce Cloud is a SaaS, Headless Microservice platform for brands. Our modern, MACH-based architecture empowers technical teams to develop innovative commerce experiences that scale. 

Every technical decision considers performance as part of its criteria.

Microservices - The API consists of a suite of microservices hosted on k8s ensuring each endpoint can be individually tested, optimized, and scaled.

Cloud Native - The system was built to be cloud-native, leveraging AWS services to improve speed, auto-scaling, and extensibility.

Go Programming Language - The individual micro-services are built on Go, which is a statically typed, compiled language. Compared to runtime languages (Java, Scala, C#) and interpreted languages (JavaScript, Python, Ruby, PHP), Go uses less memory, can sustain higher levels of concurrency, and requires fewer CPU cycles for equivalent computational tasks.

MongoDB & Redis - MongoDB and Redis create a reliable data storage solution for high-load applications requiring exceptional performance.

While Elastic Path continues to optimize and improve each aspect of the eCommerce API’s performance, the laws of physics will always be a limiting factor. Light can only travel so fast from one of AWS’s hosting regions to the end-user. To improve API speed across the world, we needed to move to the cloud edge.


Providing an enterprise-grade, scalable, extremely fast API

While Elastic Path Commerce Cloud is hosted in multiple regions across the world, issues from data residency laws to replication make having an installation close to every consumer impossible. For static files, including images and PDFs, CDNs can be reliably used to cache content at the edge, speeding up delivery and lowering latency. eCommerce data is extremely dynamic, customer carts and inventory levels cannot be cached by a traditional CDN. In addition, as an API-first solution all calls require a secure token that must be validated.

While traditional monolith eCommerce software leans heavily on multiple layers of page-level caching, this creates unnecessary complexity, forces businesses to wait for cache expirations when launching updated content and restricts the UI layer to a traditional website.

Elastic Path needed a system that could intelligently serve APIs from the edge with proper logic and cache invalidation. Fastly served that purpose with a robust network of servers and customized logic through the Varnish Configuration Language (VCL).



Elastic Path's eCommerce API Services

Discover why innovative brands are utilizing API-based commerce to scale

Explore Elastic Path's API Services

Fastly is being leveraged to serve all API requests. Due to the nature of eCommerce, many requests are user specific or have unique considerations making them difficult or impossible to cache. Elastic Path leveraged the VCL to validate requests and implement caching in the appropriate places, for example, product data requests. The logic in place provides a cache coverage of over 30% and a hit ratio over 95%. Data served from the cache has a 50-75% drop in latency. The Elastic Path team is exploring Fastly Shielding to further improve these results.


Elastic Path Commerce Cloud has an event-driven architecture. This allows the system to intelligently notify Fastly when new data is released. A set of calls to the Fastly API purges specific items from cache ensuring businesses are not left waiting for their changes to take effect. With this event drive design and Fastly’s 150-millisecond global content invalidation, this process takes seconds rather than the typical minutes to hours of traditional caching.

Additional Benefits

While the adoption of Fastly was focused on providing the best performing commerce API in the industry, it came with the added benefit of reducing overall cloud infrastructure costs. Adopting a composable commerce solution requires an upfront investment for implementation and creating a personalized experience. Being able to pass on these savings allows Elastic Path to offer the best enterprise-class commerce platform to small and medium businesses looking to grow their business.