Testing cookie behavior across hundreds of web surfaces with our in-house auditor
Our cookie auditor acts like a privacy-conscious user by visiting web pages and checking that they only load cookies consistent with that user’s preferences.
Compute that takes any shape
Fluid is Vercel's compute architecture. One system that assembles the right machine for any workload, builds, functions, or sandboxes, and reshapes it on demand.
How we raised mobile end-to-end test stability to 98% (2026) - Shopify
We rebuilt our mobile end-to-end testing framework with a strict API and computer vision, raising test stability drastically.
The Agent Access Model
The Agent Access Model proposes a new architecture to secure task-scoped agents using strict identity brokering, continuous mediation, and stateful trust.
Agentic Testing: Where Agents Fit in the E2E Testing Stack
Abstract Agent-driven end-to-end (E2E) tests add a new exploratory layer to testing, but should they replace traditional deterministic tests? We ran more than 200 agentic E2E workflows using the Playwright MCP, Playwright CLI, and agent-generated Playwright tests in test workspaces using non-production data to find out how agentic testing could fit into both our and…
Encoding Your Domain Expert: The Context Layer Behind Spotify's Data Assistant
At Spotify, data problems used to follow a specific pattern. You'd look for the relevant dashboard, there...
The Architecture Of Local-First Web Development — Smashing Magazine
An honest perspective on building local-first web apps in 2026, written for developers who’ve been doing this long enough to be skeptical of silver bullets.
Securing non-human identities: automated revocation, OAuth, and scoped permissions
Cloudflare is introducing scannable API tokens, enhanced OAuth visibility, and GA for resource-scoped permissions. These tools help developers implement a true least-privilege architecture while protecting against credential leakage.
Architecture Decision Record
Testing the impact of Adaptive Pricing across 1.5M subscription checkout sessions
Adaptive Pricing now supports subscriptions in 150+ countries, with Stripe handling currency conversion. In an A/B test across 1.5M subscription checkouts, businesses saw 4.7% higher conversion and 5.4% higher LTV per session.
From legacy architecture to Cloudflare One
Learn how Cloudflare and CDW de-risk SASE migrations with a blueprint that treats legacy debt as an application modernization project.
Conversation: LLMs and the what/how loop
A conversation between Unmesh, Rebecca, and Martin on how LLMs help us shape the abstractions in our software. We view our challenge as building systems that survive change, requiring us to manage our cognitive load. We can do this by mapping the “what” of we want our software to do into the “how” of programming languages. This “what” and “how” are built up in a feedback loop. TDD helps us operati
Connecting to production: the architecture of remote bindings
Remote bindings allow you to connect your local Worker code to deployed Cloudflare resources like R2 and D1. Come along on the technical journey of how we built this feature to create a seamless local development experience.
Building a better testing experience for Workflows, our durable execution engine for multi-step applications
End-to-end testing for Cloudflare Workflows was challenging. We're introducing first-class support for Workflows in cloudflare:test, enabling full introspection, mocking, and isolated, reliable tests for your most complex applications.
Designing For TV: Principles, Patterns And Practical Guidance (Part 2) — Smashing Magazine
After covering in detail the underlying interaction paradigms of TV experiences in [Part 1](https://www.smashingmagazine.com/2025/08/designing-tv-evergreen-pattern-shapes-tv-experiences/), it’s time to get practical. In the second part of the series, you’ll explore the building blocks of the “10-foot experience” and how to best utilise them in your designs.
LLMs bring new nature of abstraction
Everything you need to know about NIST’s new guidance in “SP 1800-35: Implementing a Zero Trust Architecture”
We read NIST’s new guidance on “Implementing a Zero-Trust Architecture” so that you don’t have to. Read this to get the key points on the newly-released NIST Special Publication 1800-35.
Reliably Detecting Third-Party Cookie Blocking In 2025 — Smashing Magazine
The web is mired in a struggle to eliminate third-party cookies, with the World Wide Web Consortium Technical Architecture Group leading the charge. But there are obstacles preventing this from happening, and, as a result, many essential web features continue to rely on cookies to function properly. That’s why detecting third-party cookie blocking isn’t just good technical hygiene but a frontline
Quick Hit #46
Straight from the W3C Technical Architecture Group: "e see an urgency to have a strict timeline for the removal of third-party cookies."
Testing sync at Dropbox
Everything in its write place: Cloud storage abstraction with Object Store
How we simplified NCMEC reporting with Cloudflare Workflows
We transitioned to Cloudflare Workflows to manage complex, multi-step processes more efficiently. This shift replaced our queues-based architecture in our National Center for Missing & Exploited Children (NCMEC) reporting system with a structured, retryable workflow that’s easier to debug and maintain.
Testing the conversion impact of 50+ global payment methods
We have data that shows when at least one additional relevant payment method beyond cards is dynamically surfaced, businesses on average see a meaningful increase in conversion and revenue.
How we built it: Payment method A/B testing
Building our payment method A/B testing tool was an industry first, and we had to find creative solutions to some of the most complex scenarios in A/B testing. We’ll share the key decisions we made—and lessons we learned—along the way.
Using the Strangler Fig with Mobile Apps
Incremental replacement of a legacy mobile application is a challenging concept to articulate and execute. However, we believe by making the investment in the pre-requisites of legacy modernization, it is posible to yield benefits in the long term. This article explores the Strangler Fig pattern and how it can be applied to mobile applications. We chart the journey of an enterprise who refused to
Introducing Netflix’s TimeSeries Data Abstraction Layer
As Netflix continues to expand and diversify into various sectors like Video on Demand and Gaming, the ability to ingest and store vast amounts of temporal data — often reaching petabytes — with…
Tophat: Crafting a Delightful Mobile Developer Experience - Shopify
Insight into how Shopify created a seamless one-click manual testing experience (known as "tophatting") for mobile applications by creating a macOS app.
Workbench: A new way to debug, monitor, and grow your Stripe integration
We’ve been testing new developer tools with thousands of users, and today, we’re announcing that the first is available: Stripe Workbench, our new home for developers that helps you debug, monitor, and grow your Stripe integration.
Unified Grid: How We Re-Architected Slack for Our Largest Customers
All software is built atop a core set of assumptions. As new code is added and new use-cases emerge, software can become unmoored from those assumptions. When this happens, a fundamental tension arises between revisiting those foundational assumptions—which usually entails a lot of work—or trying to support new behavior atop the existing architecture. The latter…
Testing the impact of buy now, pay later across 150,000+ checkout sessions
Buy now, pay later (BNPL) methods tend to be priced at a premium, so our users wanted to know whether the financial benefits would offset the added costs. We ran an experiment to help them assess when and how to offer BNPLs.
Improved Cloudflare Workers testing via Vitest and workerd
Today, we’re excited to announce a new Workers Vitest integration - allowing you to write unit and integration tests via the popular testing framework, Vitest, that execute directly in our runtime, workerd
Applying the Facade Pattern on Spotify for Artists
At Spotify, we’re dedicated to delivering a unified experience to our customers — which can sometimes be at odds with the vast, autonomous structure of . To prevent from becoming a reality, we have to be vigilant, ensuring our diverse, geographically dispersed teams don’t unintentionally create fragmented user experiences.
How to execute an object file: part 4, AArch64 edition
The initial posts are dedicated to the x86 architecture. Since then, the fleet of our working machines has expanded to include a large and growing number of ARM CPUs. This time we’ll repeat this exercise for the aarch64 architecture.
Long Live The Test Pyramid — Smashing Magazine
Is the Test Pyramid really dead? Discover the more contemporary testing strategies and evaluate the Test Pyramid’s relevance in today’s software development practices.
How to Accurately Test Significance with Difference in Difference Models
When we want to determine the causal effect of a product or business change at Spotify, A/B testing is the gold standard. However, in some cases, it’s not possible to run A/B tests. For example, when the intervention is an exogenous shock we can’t control, such as the COVID pandemic. Or when using experimental control is infeasible, such as during the annual delivery of Spotify Wrapped. In these c
Bringing Sequential Testing to Experiments with Longitudinal Data (Part 2): Sequential Testing
In of this series, we introduced the within-unit peeking problem that we call the “peeking problem 2.0”. We showed that moving from single to multiple observations per unit in analyses of experiments introduces new challenges and pitfalls with regards to sequential testing. We discussed the importance of being clear about the distinctions between measurement, metric, estimand, and estimator, and w
Bringing Sequential Testing to Experiments with Longitudinal Data (Part 1): The Peeking Problem 2.0
At Spotify, we’re constantly improving our data infrastructure, which means we can get feedback on experiments earlier and earlier. To allow for early feedback in a risk-managed manner, we use sequential tests to monitor regressions in the experiments. However, when moving toward smaller and smaller time windows, we’re faced with multiple measurements per unit in our analysis, which is known as lo
Part 2: Rethinking cache purge with a new architecture
In this post we’ll be talking about some of the architecture improvements we’ve made so far for Cache Purge and what we’re working on now
Visual Editing Comes To The Headless CMS — Smashing Magazine
Visual editing is beginning to make its way into headless architecture and the early results look promising. We’ll look at a few headless CMSs that currently support visual editing in this article.
Modernizing the toolbox for Cloudflare Pages builds
A new beta build system is now available for Cloudflare Pages. We've updated our default languages and tools, and made some exciting underlying architecture changes. You can enable it in your project settings in the dashboard today.
Load Testing for 2022 Wrapped
is Spotify’s global annual year-end campaign that celebrates our listeners with a personalized review of their listening habits over the past year.
Choosing a Sequential Testing Framework — Comparisons and Discussions
TL;DR Sequential tests are the bread and butter for any company conducting online experiments. The literature on sequential testing has developed quickly over the last 10 years, and it’s not always easy to determine which test is most suitable for the setup of your company — many of these tests are “optimal” in some sense, and most leading A/B testing companies have their own favorite. Even though
The 25 Percent Rule for Tackling Technical Debt - Shopify
Let’s talk about technical debt. Let’s talk about practical usable approaches for actually paying it down on a daily, weekly, monthly, and yearly basis. Let’s talk about what debt needs to be fixed now versus what can wait for better planning.
Cloudflare Application Services for private networks: do more with the tools you already love
Today, we’re excited to announce new integrations that make it possible to unlock operational and cost efficiencies for IT teams by allowing them to do more with fewer tools, and enable new use cases that are impossible without Cloudflare’s “every service everywhere” architecture.
Setting up a screen reader testing environment on your computer
Sara Soueidan with everything you need, from what screen reading options are out there all the way to setting up virtual machines for them, installing them,
The road to a more standards-compliant Workers API
We have been making improvements in the Workers runtime to increase alignment with Web Platform standards around event handling, task cancellation using AbortController, text encoding and decoding, URL parsing and pattern matching, and streams support.
A New Pattern For The Jamstack: Segmented Rendering — Smashing Magazine
Among all possible architectures for rendering a website, static rendering is the most performant. Yet, it’s only applicable to public, generic content. Or is it? In this article, we will push the boundaries of static rendering and learn how to apply it to personalized content. This new pattern is called “Segmented Rendering” and will change the Jamstack game forever.
Testing The CLI The Way People Use It — Smashing Magazine
Have you ever wondered, why do people write CLI tools? When is a good time to think about yours? Today we’ll touch on these questions, along with some tips to remember when creating one. However, all of this serves as a prelude to the real topic: end-to-end testing of CLI tools.
How To Create An Information Architecture That Is Easy To Use — Smashing Magazine
If users cannot find the answers to their questions or are not exposed to critical messaging, they will not act, and your website will fail. To prevent that from happening, you need an effective information architecture. In this article, Paul Boag provides you with a process to ensure you have precisely that.
What Web Frameworks Solve: The Vanilla Alternative (Part 2) — Smashing Magazine
rameworks provide convenient ways to achieve complicated tasks, and they have benefits beyond technical ones, such as aligning a group of developers to a particular style and pattern. The web platform offers many choices, and adopting a framework gets everyone at least partially on the same page for some of those choices. In this second part, Noam suggests a few patterns of how to use the web plat
Miniflare 2.0: fully-local development and testing for Workers
We're thrilled to announce the release of the next major version: a more modular, lightweight and accurate Miniflare 2.0
Fix the unit test and open a giant hole everywhere
Local Testing A Serverless API (API Gateway And Lambda) — Smashing Magazine
Have you ever struggled with testing cloud services locally? Specifically, have you ever struggled with locally testing an API that uses API Gateway and Lambda, with the Serverless framework, on AWS? In this article, Tom Hudson shares a quick overview of how easy it is to quickly set up your project to test locally before deploying to AWS.
Let’s Dive Into Cypress For End-to-End Testing — Smashing Magazine
Is end-to-end testing a painful topic for you? End-to-end testing does have some pitfalls that are cause for concern. Let’s look at how to prevent many of them. In this article, Ramona Schwering explains how to handle end-to-end testing with Cypress and make it make it not so tedious and expensive for yourself, but fun instead. hope to show you that end-end testing can be fun!
A Kotlin Style .copy Function for Swift Structs - Shopify
Swift’s struct isn’t as convenient as Kotlin’s data class because it doesn't have a similar copy function. Learn how to adopt this pattern in Swift.
Diggin’ and Fetchin’ with TruffleRuby - Shopify
It begins with a clever Ruby trick to extract a value from a deeply nested hash we want to refactor and ends with a prototype changing the language itself.
Maintaining End-To-End Quality With Visual Testing — Smashing Magazine
A critical part of any developer’s workflow is definitely testing. It helps us to ensure that our project is going to maintain a high level of quality, as well as prevent any pesky bugs from getting out into the wild. By adding visual elements to your tests, you can gain more options to add meaningful ways in maintaining a high level of quality for your app. In this article, Colby Fayock explains
Email Testing Flow As It Should Be — Smashing Magazine
Email sending functionality is an integral part of every digital product that involves communication with its users (read: any online service). With so many tools and approaches, email still has quite a few pain points, both for developers and email marketers. Email is difficult because it has too many aspects to set and a few instances with no common rules to follow.
It’s A (Front-End Testing) Trap! Six Common Testing Pitfalls And How To Solve Them — Smashing Magazine
When writing front-end tests, you’ll find a lot of pitfalls along the way. In sum, they can lead to lousy maintainability, slow execution time, and — in the worst case — tests you cannot trust. But it doesn’t have to be that way. In this article, I will talk about common mistakes developers make, at least in my experience, and, of course, how to avoid them. Testing doesn’t need to be painful, afte
Spinning Up Multiple WordPress Sites Locally With DevKinsta — Smashing Magazine
When developing themes and plugins for WordPress, we need to test them in different environments. How can we create multiple testing sites on our computer, quickly and easily, without having to become a sysadmin? If our themes and plugins contain custom blocks, testing them for all different versions is imperative. At the very minimum, we need to worry about two versions of Gutenberg: the one ship
