Zalando · Engineering blog · 1 a month · 104 posts since Sep 8, 2020
Oct 30
How we migrated production MLflow models from Python 3.10 to 3.12 without retraining, using a "Load and Repack" strategy to recover cloudpickle-serialized artifacts and future-proof our ML architecture.
Oct 12
Automating schema mapping for diverse supplier data using a RAG Flywheel and LLMs.
Oct 8
A client-side circuit breaker stays open for hours, blocking 95% of traffic, and won't close. Our service shows no sign of being unhealthy.
Sep 25
As part of our agentic platform initiative, we are open-sourcing the Agentic Identity Broker, a central component for user-to-agent delegation, consent, and token exchange that lets agents act on behalf of users without ever holding...
Sep 1
Budget Split and Orthogonal Concurrency reduce budget cannibalization bias and enable reliable concurrent experiments in two-sided AdTech marketplaces.
Aug 14
We look back at our journey of agentic engineering at Zalando, sharing our learnings and approaches that worked well for us in the past 2.5 years.
Jul 24
We replaced a homegrown in-memory stream join with Apache Flink, halved our infrastructure cost, and eliminated in-memory state loss on restarts.
Jun 23
How we built an in-process client-side load balancer for a million requests per second of internal fan-out traffic, what we layered on top (N-ring fade-in, occupancy-based bounded load, and AZ-aware routing with a latency health factor)...
Jun 8
Automate telemetry query migration from Lightstep UQL to PromQL with this open-source Go SDK and Web UI.
Apr 9
How Zalando used Skipper as a validating admission webhook to reject invalid filters and predicates at apply time, and what it took to make that safe on the Kubernetes control-plane path.
Mar 17
Deep dive into how Zalando builds a search quality assurance framework with LLM-as-a-judge to evaluate the search quality at scale with high coverage and multi-language support.
Mar 9
How we integrated jackson-datatype-money into the official FasterXML Jackson ecosystem.
Mar 4
The beauty of a high-level abstraction is that it lets you focus on the "what" rather than the "how." In the world of Apache Flink, the Table API is a powerful tool that abstracts away the complexities of stream processing, allowing...
Jan 29
In September 2024, we started an Engineering Papers guild at Zalando to read and discuss research papers together. A year later, we reflect on our journey and share insights on organising and evolving the guild.
Jan 15
Learn how the ZEOS replenishment optimization system achieves up to 22.1% GMV uplift by unifying probabilistic demand forecasting with risk-aware discrete event simulation.
Dec 19, 2025
How we contributed two features to Debezium to solve WAL growth and enable safer logical replication for our event streaming infrastructure
Dec 17, 2025
Once upon a time, during a normal Sunday, our team ran into an unexpected challenge: an Elasticsearch cluster that suddenly became sluggish and unresponsive due to a self-inflicted Denial of Service (DoS) attack (of course we didn't know...
Oct 3, 2025
We present how we combined our internal React-based UI composition framework Rendering Engine with React Native in a brownfield integration approach that enables us to gradually modernise our mobile app technology stack while at the same...
Sep 25, 2025
Your incidents hold the blueprint to your most strategic infrastructure wins, if you're listening correctly.
Jul 8, 2025
In this post, we explain how we transformed fragmented partner data sharing at Zalando by implementing Delta Sharing, evolving from a pilot solution to an organization-wide platform that enables real-time, secure data access across our...
Jun 30, 2025
This technical blog outlines how we built a scalable inventory optimization system to help partners maintain a profitable inventory.
May 19, 2025
This article discusses the challenges of returning to work in a fast-paced tech environment and how to navigate them.
Mar 7, 2025
In this post, we explain how we replaced an event-driven system with a high performance API capable of serving millions of requests per second with single-digit-millisecond latency at P99
Feb 20, 2025
Sharing our approach and insights employing LLMs to migrate in-house UI component libraries at scale.
Feb 17, 2025
A proxy server contributing to a stable Kubernetes cluster and scaling ingress controller.
Platform, data and ML engineering at Europe’s fashion platform.
AI and agents (3), Reliability and performance (2), Developer tools (2) in the last six months.
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