Josef Goldstein

At @Wix, we cut monthly cloud data 📊 costs by 50% (!) - while running 100K+ tables across 2 Iceberg catalogs and trillions of CPU milliseconds in Trino & Spark. Here’s how we did it (without slowing teams down!): ⚙️ Job-level telemetry & ownership across Trino, Spark, and Airflow (100% coverage via Platyspark) 💰 Simple cost models (e.g. $0.000002 per Trino CPU ms) and efficiency KPIs like “cost per 1B clickstream events” 📊 Dashboards that drive accountability, surfacing daily usage for every team 🙌 Engaged data teams - quick wins (95% storage savings by reducing job frequency) - deeper refactors Read the full story (part 2) by @frolovv wix.engineering/post/how-wix…

Wix Engineering 📌 Newsletter, Issue 78: Cutting Costs, Boosting Resilience, and Smarter AI Packed with engineering insights, developer stories, and tools to help you build better, faster, and smarter. This month, we’re diving into cost-cutting wins, platform resilience, AI-powered coding, and productivity tips. 👉Here’s what’s inside: 1. How @Wix Cut 50% of Its Data Platform Costs (Part 1) @frolovv explains how we unified multi-cloud cost data, solved tagging challenges, and built a cost model that slashed platform costs by half - without hurting performance. 2. Engineering Resilience: Behind Wix’s Global Platform Ben Chen shares how our Production State and Traffic Light systems cut MTTR by 80% and automated 60% of traffic management, ensuring seamless uptime for millions of sites. 3. Distributing Context Across Repositories In this talk, @ranyitz shows how @cursor_ai's rules and Wix’s aicm tool make AI assistants far more effective by carrying context across sessions and repos. 4. How Wix Slashed Spark Costs by 50% Almog Gelber walks through our migration of 5,000+ Spark workflows from EMR to EMR on EKS - achieving 50% lower costs, 5x faster spin-up times, and a 99% transparent transition. 5. More Insights We Liked - A roundup of great reads from Wix engineers and beyond: * Words Matter: How Prompting Shapes Accuracy, Speed, and Cost - @GoldsteinJosef on why prompt design makes or breaks #LLM performance. * Harnessing Simulation - Ori Morhaim on using simulation to optimize staffing and ticket routing in customer care. * The AI Code Velocity Trap - @schuftan on why AI-generated speed can create "day-one legacy code" and how to prevent accountability debt. * Must-Have Mac Apps in 2025 - @saar_shechter’s top productivity apps plus Reddit’s hidden gems. --- 👉 Read the full newsletter here: wix.engineering/so/90PZWubU3

At @Wix, we pulled off a massive 🚀 move: We migrated 5,000+ daily Spark applications from AWS EMR to EMR on EKS. The results? * 50% cost reduction * Spin-up times cut from 10-15 minutes to just 2-3 minutes * 99% transparent migration EMR on EKS combined with Apache YuniKorn is truly a game-changer for big data workloads. Read the full story here: wix.engineering/post/how-wix…

Yes, we managed to cut our data platform costs by 50%. In Part 1 of our blog series, @frolovv shares how: - Multi-cloud chaos turned into a unified view - Usage attribution became a reality - Tagging became enforceable If you're scaling a data platform - read this: wix.engineering/post/how-wix…

Our new @Wix Engineering 📌 newsletter edition is here - packed with technical breakthroughs, developer stories, and tools to help you build better, faster, and smarter! This month, we’re diving deep into how chaos, AI, and monorepos are reshaping the way we work. Here’s what’s inside: 1. We Added Chaos - And Got Stability Back @schuftan's story on how AI chaos testing made our CI/CD pipelines more resilient - was covered by @InfoQ 2. From RAG to MAG: The 95% Leap in Data Discovery We swapped Retrieval-Augmented Generation (#RAG) for Model Assisted Generation (MAG) and boosted our AI data discovery accuracy to 95%! @Rafa_sasson walks through what we changed, why it worked, and what’s next. 3. From 60 Repos to One: How Wix Tackled #Monorepo Migration - Part 2 @ZachiNachshon shares how we transformed our backend monorepo using graph-based dependency tracking to handle AI-scale code generation. 4. We’re Sponsoring @reversim Summit 2025! Come meet us at the conference. Also - check out our sponsor page for: Five open roles, dev testimonials from inside Wix (@NSilnitsky, Evelyn Moadi and Neria Poria Yashar), tech stack snapshots, and a sneak peek at Wix Campus 5. And there’s more! Explore additional technical stories and case studies by @DorBenB, @guy_bary, @iamlukasniessen, and @NetflixEng team. * Read it here: wix.engineering/so/c5PXAgNo0 * Subscribe here: wix.engineering/subscribe

From 83% to 95% accuracy in picking the right data - a big leap in how we do data discovery at @Wix. We moved from RAG to MAG, using advanced #LLMs to reason over full data models and deliver smarter, faster results. How did we do it - and what’s next? Read the full story, "The 95% Breakthrough" by @Rafa_sasson: wix.engineering/post/the-95-…

Heading to Data TLV tomorrow? Don’t miss @YaelRafa’s talk, "Finding the Needle in the Data Swamp: A Multi-Agent AI Approach to Data Discovery", and the session by Guy Levinhr and Tal Sheldon, "Scaling a Real-Time Feature Store: @Wix’s Journey from Legacy to Innovation". Good luck to Yael, Guy, and Tal - looking forward to seeing you on stage!

You can learn more about @YaelRafa's upcoming #DataTLV session in her new article: Solving Data Discovery at Scale: How @Wix Uses RAG and Multi-Agent Systems to Find the Right Data Fast: wix.engineering/post/solving…

How do you find the right data when you’re dealing with thousands of sources, hundreds of teams - and everyone speaks a different language? At @Wix, we faced a massive challenge: enabling data discovery at scale in a data mash environment - a decentralized, domain-driven environment. Teams owned their data. Context lived in people’s heads. The result? Knowledge silos, lost time, and frustrated developers. So we built Anna - an intelligent assistant powered by a semantic layer, RAG, and multi-agent systems - to help teams find the right data, fast. Here’s how we tackled the complexity and made data truly discoverable: wix.engineering/post/solving…