Engineering blogs

• Expedia Group Technology - Engineering Exploring the strategy pattern and functional programming alternatives in Kotlin Photo by Karsten Winegeart on Unsplash When designing soft

• New features to help SaaS platforms manage risk and stay compliant Platforms tell us that managing risk and compliance often feels like choosing between speed and safety. • You n

• Written by Spencer Koch and Pratik Lotia. • https://preview.redd.it/64cne7jctm4g1.png?width=1600&format=png&auto=webp&s=ee1af9952a1c42786d982f7df0e18a03db27bd4b Hey everyone! • S

• Slack’s Security Engineering team is responsible for protecting Slack’s core infrastructure and services. • Our security event ingestion pipeline handles billions of events per d

• Introduction Ten years ago, we launched our bug bounty program in partnership withHackerOne. • Beyond a security initiative, it represented an open invitation to collaborative de

• Building the future: highlights from Dropbox’s 2025 summer intern class This summer, the Emerging Talent team proudly welcomed 43 interns to Dropbox as part of our 2025 Camp Drop

• Real-time data quality monitoring: Kafka stream contracts with syntactic and semantic test Introduction In today’s data-driven landscape, monitoring data quality has become a cri

• I n 2021, we published a blog post titled ’ Increasing experimentation accuracy and speed by using control variates ,’ describing how we reduce the variance of metrics using CUPE

• Authors: Andrew Garrett, Md Mansurul Bhuiyan With 10s of thousands of new posts on Reddit each day, identifying content that is simultaneously timely, newsworthy, and engaging pr

• Evolution and Scale of Uber’s Delivery Search Platform 24 November 2025 / GlobalIntroduction Search is a primary discovery funnel for Uber Eats: a large share of orders start wit

• SpellVault’s evolution: Beyond LLM apps, towards the agentic future Introduction At Grab, innovation isn’t just about building new features; it’s about evolving our platforms to

• Introduction At Uber, scale and reliability define our infrastructure. • Every new server type, kernel upgrade, and configuration change must be rigorously vetted before it touch

• Background A Voluntary Product Accessibility Template (VPAT) is a document that outlines how well a product aligns with accessibility (a11y) standards. • Its primary purpose is t

• Enhancing Uber’s Guidance Heatmap with Deep Probabilistic Models 18 November 2025 / GlobalIntroduction At Uber, giving high quality guidance to drivers is crucial for smoothing t

• Written by Chris Fournier. • In 2024, Reddit teams used a variety of solutions to perform approximate nearest neighbour (ANN) vector search. • From Google’s Vertex AI Vector Sear

• When we first built Dash, it looked like most enterprise search systems: a traditional RAG pipeline that combined semantic and keyword search across indexed documents. • It worke

• I/O Observability for Uber’s Massive Petabyte-Scale Data Lake 13 November 2025 / GlobalIntroduction As Uber’s data infrastructure evolves toward a hybrid cloud architecture, unde

• Expedia Group Technology - Engineering Colocating Input Partitions with Kafka Streams When Consuming Multiple Topics: Sub-Topology Matters! • Understanding how sub-topology desig

• Create new monetization opportunities with Stripe Billing’s recent upgrades Atlassian, Figma, Instacart, and fast-growing AI companies such as OpenAI, Anthropic, and NVIDIA use S

• Author: Cedric Blondeau TL;DR We migrated Reddit’s Home Feed Ranker from CPU to GPU to unlock scalability, efficiency, and enable further growth with new architectures like Trans

• We manage the build pipeline that delivers Quip and Slack Canvas’s backend. • A year ago, we were chasing exciting ideas to help engineers ship better code, faster. • But we had

• Grab’s Mac Cloud Exit supercharges macOS CI/CD Introduction In our mission to optimize continuous integration and delivery (CI/CD), we have taken a bold step by relocating our in

• How we built a custom vision LLM to improve document processing at Grab Introduction In the world of digital services, accurate extraction of information from user-submitted docu

• By Brentley Jones Background The Reddit iOS project requires macOS hosts to build and test since it depends on Xcode/Apple SDKs. • Because of this, our CI agents also needed to r

• Rarely are there opportunities for big, bold, game-changing improvements in web performance. • The Speculation Rules API (SRA) is a recent browser development that offers just su

• Author: Ken Struys Developer Experience (aka DevX) mission is to increase developer velocity at Reddit. • We build (and buy) highly leveraged tools used across the entire softwar

• EXPEDIA GROUP TECHNOLOGY - ENGINEERING Reimagining Software Engineering: LLMs, MCP, and the Dawn of a New Programming Paradigm Programming by prompting isn’t the future - operati

• Last year, I wrote a blog post titled Advancing Our Chef Infrastructure, where we explored the evolution of our Chef infrastructure over the years. • We talked about the shift fr

• With Mobius Labs’ Aana models, we’re bringing deeper multimodal understanding to Dropbox Dash Teams today create and share more types of content than ever before. • Their work mi

• Editor’s note: We are republishing a blog post from the Mobius team, originally published in 2023, that introduced a now widely used quantization algorithm. • We plan to continue

• Written by Pratik Lotia. • A confession: I love talking about my job, but nailing down a typical ‘Day in the Life’ is a challenge when every day at Reddit InfraSec feels like a n

• Interviews AI Interview Success: An Interviewer’s Inside Guide From the Other Side of the Screen: What We’re Looking For in Your AI-Assisted Interview I’ve had the pleasure of co

• Thanks to everyone who submitted questions for u/cometarystones ’ AMA! • We received so many great questions. • We’ve compiled Flee’s responses into this post. • Read along for t

• For more than 20 years, Etsy has been the destination for human creativity online. • Our marketplace is home to more than 100 million special items made, handpicked and designed

• Ever wanted to ask our CISO, Fredrick ‘Flee’ Lee, u/cometarystones , something about security, leadership, or why he always seems so chill even under pressure? • If so, now’s you

• Imagine you have a fabulous idea to drive more sales on Etsy by giving out free ice cream with every purchase. • How would you know if it will actually work? • One way to test th

• Written by Vignesh Raja and Jerry Chu. • Background and Motivation In a previous post , we introduced Signals-Joiner, a Flink application that enriches input for our real-time, a

• It’s mid 2023 and we’ve identified some opportunities to improve our reliability. • Fast forward to January 2025. • Customer impact hours are reduced from the peak by 90% and con

• LLM applications present a deceptively simple interface: a single text box. • But behind that minimalism runs a chain of probabilistic stages, including intent classification, do

• EXPEDIA GROUP TECHNOLOGY - DATA Stop overwriting - start merging: a smarter approach to updating Iceberg tables Photo by NEOM on Unsplash Apache Iceberg has emerged as a leading

• Written by Dylan Glenn. • Here at Reddit, the Enterprise Applications team shepherds much of the financial and operational infrastructure for our business, from invoicing custome

• S3 server access logs at scale - Nurdan Almazbekov, Infrastructure Security - Sep 26, 2025 Introduction Yelp heavily relies on Amazon S3 (Simple Storage Service) to store a wide

• Share: Today, we’re announcing some changes that will improve the security of accessing Git data over SSH. • We’re adding a new post-quantum secure SSH key exchange algorithm, kn

• As cyberattacks evolve to unprecedented levels of sophistication and speed, the time gap between breach detection and response has never been more critical. • Traditional securit

• Every day, shoppers from Etsy’s community of nearly 90M buyers visit our marketplace to search for unique, handmade, and vintage items. • But with over 100 million listings, how

• EXPEDIA GROUP TECHNOLOGY - DATA A strategic shift toward data flows that are version-controlled, testable, and auditable Ensuring data quality in production environments is criti

• Hack Week 2025: How these engineers liquid-cooled a GPU server Hack Week 2025 at Dropbox centered on the theme ‘Keep It Simple,’ offering opportunities for innovation, experiment

• This post investigates the benefits and limitations of prompt engineering in two instances of AI-assisted onboarding relying on large language model (LLM) technology. • Of partic

• Draw tool From Intern Project to Production: How I Shipped the Draw Tool for Canva’s Present Mode Overview of the technical hurdles I overcame to evolve my intern project into a

• Expedia Group Technology - Data Beyond the Handoff: Boosting Machine Learning Outcomes Through Integrated Scientist and Engineer Collaboration Bridging the gap between innovation

• Expedia Group Technology - Data Contextual Property Embeddings for Corse-grained Personalization How Expedia Group uses embeddings for personalized hotel search – Listen Share I

• CHAOS is Yelp’s server‑driven UI framework delivering dynamic content via GraphQL. • Clients query the CHAOS API, which forwards to a federated GraphQL subgraph. • Apollo Federat

• Data Analytics Measuring Commercial Impact at Scale at Canva How We Built Canva’s IMPACT App with Streamlit in Snowflake Executive Summary At Canva, experimentation is at the cor

• Canva now requires Backend, ML, Frontend candidates to use AI tools (Copilot, Cursor, Claude) during interviews. • Nearly 50% of current engineers use AI daily to prototype, navi

• Product engineers build the final product, while platform engineers supply the tools and infrastructure. • GitHub’s infrastructure team now serves internal customers, shifting fo

• Revenue Data Pipeline handles massive data, complex transformations to recognize revenue. • Original Redshift Connector sync caused ~10-hour latency, delaying data verification.

• GitHub Issues search now supports logical AND/OR operators across all fields. • Nested parentheses allow precise grouping of query terms for complex searches. • Example: is:issue

• Preset annotations embed accessibility details into design system components for designers and developers. • Primer’s preset system is unique but can inspire custom annotation fr

• Accessibility annotations bridge gaps design systems can’t fix, ensuring inclusive component usage. • Misconception: accessible components guarantee accessible designs; design fl

• Nrtsearch 1.0.0 introduces incremental S3 backups on every commit, enhancing data durability. • Over 90% of Elasticsearch traffic has migrated to Nrtsearch, proving its productio