Introduction
Erwin Müller is one of Germany’s most established home and lifestyle retailers, offering a comprehensive range of textiles, bedding, bath products, tableware, and home decor. With a heritage built on quality, reliability, and a deep understanding of customer needs, Erwin Müller has successfully grown its digital presence into a primary revenue channel, serving millions of shoppers through de.erwinmueller.com.
"The data is unambiguous: a +1.74% conversion rate uplift and a projected +2.29% revenue increase from a single performance integration. What made this possible was the depth of expertise the Speed Kit team brought to the table. They didn’t just deploy a solution - they ran a thorough RUM analysis, identified specific INP bottlenecks on mobile, and showed us exactly what needed fixing. That kind of proactive, data-driven partnership is what turns good results into outstanding ones."
Challenge
As the expectations of online shoppers have risen sharply, Erwin Müller recognized that page load performance had become a critical differentiator. Mobile users in particular expect fast, smooth browsing experiences - and any friction in the journey from landing to checkout has a direct and measurable impact on conversion and revenue. Addressing this at scale, without disrupting existing systems or burdening the engineering team, required a targeted and proven solution.
Solution
Speed Kit was deployed to tackle this challenge head-on. Through a rigorous 50/50 A/B test running from February 4 to February 25, 2026, Speed Kit demonstrated clear and consistent improvements in load times, user engagement metrics, and most importantly, significant commercial results.
Speed Kit is an official ACE eligible technology partner and independent software vendor (advanced tier) of the AWS Competency Partner Program "Accelerate" as well as the Workload Migration Program. Our technology is powered by 13 different AWS services:
- Elastic Kubernetes Service (EKS): We use EKS to schedule and orchestrate our Speed Kit applications on EC2 instances.
- Simple Storage Service (S3): Speed Kit stores cached assets in S3 buckets. Additionally, we store RUM (Real User Monitoring) and PI (Performance Insights) data in S3 buckets for analytics purposes.
- Elastic Compute Cloud (EC2): Our workloads are hosted on EC2 instances, as managed through EKS.
- Kinesis Data Streams: Kinesis Data Streams are used to ingest RUM and PI data from Speed Kit, which is then consumed by Amazon Managed Service for Apache Flink. Fastly also streams access logs to our Kinesis Data Stream, which are similarly consumed by Amazon Managed Service for Apache Flink.
- Athena: We use Amazon Athena to query data stored in AWS S3 buckets, enabling performance insights and asset preloading.
- Elastic Container Registry (ECR): Docker images are stored in ECR and deployed in our Kubernetes cluster, which is managed by EKS. For third-party application images, we use the pull-through-cache feature of ECR.
- Elastic Container Service (ECS): We build Docker images using a service hosted on Amazon ECS.
- Route 53: Route53 is used to manage DNS records.
- Simple Email Service (SES): We use SES is used for sending transactional emails.
- Managed Streaming for Apache Kafka (MSK): We use MSK to facilitate consuming and producing custom event records for different applications.
- DynamoDB: Speed Kit uses DynamoDB to store information related to our predictive preload feature.
- Lambda: We use Lambda to pre-render client side renderd pages to make that actual server side rendered.
- ElastiCache (Redis OSS): We use ElastiCache to store our Bloom filter, which checks whether an asset is present in our cache.
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Click the image to open the architectual diagram of Speed Kit with AWS
Results
Speed Directly Drives Commercial Results
The performance improvements translated directly into measurable commercial outcomes. The A/B test data shows a directly observed +1.74% conversion rate uplift between the Speed Kit group and the control group, alongside a projected +2.29% revenue uplift. Together, these figures make a compelling and data-backed business case for a full rollout across de.erwinmueller.com.
Session length improved by 2.3% — with every 100 ms of LCP improvement corresponding to a +1.58% increase in session length, meaning faster users navigate significantly more pages per visit. Bounce rates also fell substantially as load times decreased, further reinforcing the commercial case.
Interaction to Next Paint (INP)
After the fix provided by Speed Kit's inhouse Google Developer Experts in web technologies, the INP on mobile has risen from 19% to 95% green.
Category Pages: The Most Impactful Uplift
Category pages are the primary discovery and browsing surface for Erwin Müller’s shoppers. LCP improved by 41% - 214 ms faster at the median, dropping from 522 ms to 308 ms. Faster category browsing means more products considered, longer sessions, and a shorter path to purchase.
Instant Navigation: 81% of Traffic Loads in Under 1 Second
With Speed Kit, 81% of all page loads now complete within 1 second, a threshold that defines a genuinely fast experience for users. Even more striking: the share of pages loading within 300 ms has tripled compared to without Speed Kit.
