---
title: "Latest reads"
description: "The engineering internet, summarised so you can actually read it."
---

# Latest reads
> The engineering internet, summarised so you can actually read it.

## Articles

### [Bringing Javascript to WebAssembly for Shopify Functions](https://yomu.fyi/post/bringing-javascript-to-webassembly-for-shopify-functions.md)
- Company: [Shopify](https://yomu.fyi/company/shopify.md)
- Author: 2023-10-18
- Published: Feb 9, 2023
- Type: Announcement

Shopify is introducing a Local Developer Preview that lets developers run JavaScript Shopify Functions locally, alongside Rust, while production deployment remains unavailable. Shopify Functions execute as WASI modules that read JSON from stdin and write JSON to stdout, with a 256KB size limit and a five-millisecond runtime limit; the post notes that the timing constraint varies by machine load. Javy addresses JavaScript’s WebAssembly runtime challenge by bundling the QuickJS interpreter into a Wasm binary, using Rust wrappers and Wizer to snapshot compiled QuickJS bytecode. Initial tests found Javy-created modules about three times slower than equivalent Rust modules, but both are likely to stay under five milliseconds for realistic use cases; Shopify is also pursuing SpiderMonkey in Wasm and researching JIT support for future performance.


### [Supabase Beta January 2023](https://yomu.fyi/post/supabase-beta-january-2023.md)
- Company: [Supabase](https://yomu.fyi/company/supabase.md)
- Author: ant\_wilson
- Published: Feb 8, 2023
- Type: Announcement

Supabase’s January 2023 beta update gathers releases across Postgres, GraphQL, Edge Functions, client libraries, image transformation, and self-hosting. The update adds pgvector, a PostgreSQL extension for storing OpenAI embeddings and performing vector similarity search, and presents Supabase Clippy, a one-week, fully open-source documentation-search MVP combining pgvector with OpenAI. pg\_graphql now supports Views, Materialized Views, and Foreign Tables, while Image Transformations enable automatic WebP conversion by default, with format: origin available to opt out. Other changes include Python and C# reference documentation, pg\_repack, multi-tab authentication logout through BroadcastChannel, lz4 compression, ICU locales, downloadable Edge Function source, and a DigitalOcean deployment guide using Sendgrid, Packer, and Terraform. Supabase also reports reaching 45,000 GitHub stars and a position among the top 200 most-popular repositories.


### [The Complex Data Models Behind Shopify's Tax Insights Feature](https://yomu.fyi/post/the-complex-data-models-behind-shopify-s-tax-insights-feature.md)
- Company: [Shopify](https://yomu.fyi/company/shopify.md)
- Author: 2023-10-18
- Published: Feb 8, 2023
- Type: Explainer

Shopify Tax’s Tax Insights feature provides merchants with state-level information about sales-tax liability and approaching liability, amid U.S. rules that vary by jurisdiction, product, threshold, and evaluation period. The implementation modified existing data models, added four new ones, and represented changing tax rules with lookup data containing valid\_from and valid\_to dates, including thresholds, date ranges, inclusions, exclusions, and inclusive or exclusive comparisons. Teams prototyped models in BigQuery SQL, implemented them in PySpark and Spark jobs, and combined merchant monthly taxable-sales aggregates with the rule model to evaluate economic nexus; the architecture moved source data through GCS and a warehouse into a final model. Each run publishes merchant-keyed insights to Google Cloud Bigtable, where the core application retrieves them for the frontend, while warehouse data supports analytics and other processes.


### [Supabase Clippy: ChatGPT for Supabase Docs](https://yomu.fyi/post/supabase-clippy-chatgpt-for-supabase-docs.md)
- Company: [Supabase](https://yomu.fyi/company/supabase.md)
- Author: paul\_copplestone
- Published: Feb 7, 2023
- Type: Announcement

Supabase introduced “Supabase Clippy,” a ChatGPT-like interface trained on its documentation, as a hidden MVP in the Supabase docs. It responds to questions by retrieving relevant documentation and streaming GPT-3's answer in realtime. The implementation parses docs into sections, creates OpenAI embeddings, stores them in Postgres with pgvector, and injects matching documents as context for generation. The project was motivated by the growth of Supabase's product suite and documentation, plus the need to support developers unfamiliar with Postgres; the current version uses only Guides and is presented as a one-week MVP intended to gather feedback. Planned directions include adding reference docs and community discussions, caching repeated queries, thumbs-up relevance feedback, and interactive guidance.


### [Storing OpenAI embeddings in Postgres with pgvector](https://yomu.fyi/post/storing-openai-embeddings-in-postgres-with-pgvector.md)
- Company: [Supabase](https://yomu.fyi/company/supabase.md)
- Author: gregnr
- Published: Feb 6, 2023
- Type: Tutorial

Post describes how embeddings represent semantic relatedness as vectors and how OpenAI’s text-embedding-ada-002 model produces 1536-dimensional embeddings for text. It addresses storing and searching large or dynamically changing collections that may not fit comfortably in memory, using PostgreSQL and the pgvector extension instead of a small CSV-and-NumPy workflow. The implementation enables the vector extension, creates a documents table with a vector(1536) column, and defines match\_documents() with cosine distance, thresholds, counts, and ordering. It also shows JavaScript code for generating embeddings, a search flow that retrieves matching documents for prompt context, and token limiting before a completion request, while noting that documents can be chunked. For larger tables, the post recommends an ivfflat index with vector\_cosine\_ops and gives 4 \* sqrt(table\_rows) as a starting point for lists.


### [The Hardest Part of Writing Tests is Getting Started](https://yomu.fyi/post/the-hardest-part-of-writing-tests-is-getting-started.md)
- Company: [Shopify](https://yomu.fyi/company/shopify.md)
- Author: 2023-10-18
- Published: Feb 2, 2023
- Type: Tutorial

The article presents getting started with automated testing as the main obstacle, especially when a full suite requires helper tools, stubs, and fixtures that can overwhelm beginners. It argues that tests serve as executable documentation, preserve intended behavior and edge cases, and expose regressions before changes reach production. The recommended progression is to install a framework and verify both passing and failing tests, cover isolated functions, add stubs with sanitized API-response fixtures, and then build end-to-end tests while monitoring coverage. In an ETL example, API stubbing avoided expensive, slow calls, while database checks validated loaded and transformed data; the resulting tests covered more than 80 percent of the codebase and saved time for the author and team. The article also proposes E2E tests as a way to safely approach legacy code before refactoring it.


### [Carving The Scheduler Out Of Our Orchestrator](https://yomu.fyi/post/carving-the-scheduler-out-of-our-orchestrator.md)
- Company: [Fly.io](https://yomu.fyi/company/fly-io.md)
- Published: Feb 1, 2023
- Type: Explainer

Fly.io describes why it is carving scheduling out of its existing Nomad-based orchestrator and replacing it with a simpler system centered on flyd and AppsV2. It first reduces orchestration to a client-server supervisor, then explains centralized scheduling: workers register resources, while a server filters candidates by constraints and ranks them. The proposed design avoids jobs sitting pending or being placed in nearby but incorrect regions; requesting VMs in MAD yields MAD capacity or nothing. Policy-heavy behavior such as deployment spares, crash recovery across workers, and regional decisions moves into flyctl and other platform components rather than the scheduler. Fly Machines already exposes APIs to reserve, start, and stop individual VMs, with Nomad still used in January 2023 and flyd expected for deployments in December 2023.


### [Performance Testing At Scale—for BFCM and Beyond](https://yomu.fyi/post/performance-testing-at-scale-for-bfcm-and-beyond.md)
- Company: [Shopify](https://yomu.fyi/company/shopify.md)
- Author: 2023-10-18
- Published: Jan 27, 2023
- Type: Benchmark

Shopify treats Black Friday Cyber Monday (BFCM) as its most critical period, and uses full-scale BFCM Scale Testing to assess whether the platform can handle peak traffic. Preparation combines capacity planning, resiliency testing, single-application performance testing, and repeated exercises that scale core services to their BFCM profiles before generating load. The hybrid architecture centers on Shopify Core, a monolithic Ruby application supported by services for storefront rendering, analytics, fraud analysis, payments, webhooks, and more. Five load flows cover browsing and buying, admin activity, flash sales, Storefront APIs, and Hydrogen and Oxygen, with Cronograma layering requests gradually and providing an abort switch. The exercises surfaced connection-count pressures, a Kubernetes ingress-nginx endpoint limit, and uneven load-balancer distribution; mitigations included refactoring, scaling dependent services, increasing pod capacity, and dedicated nginx node pools.


### [From Farmer to Security Engineer: How Dev Degree Helped Me Find My Dream Job](https://yomu.fyi/post/from-farmer-to-security-engineer-how-dev-degree-helped-me-find-my-drea.md)
- Company: [Shopify](https://yomu.fyi/company/shopify.md)
- Author: 2023-10-18
- Published: Jan 26, 2023
- Type: Explainer

Cailyn Edwards recounts how she moved from leaving high school and running an organic farm to a career in infrastructure security through Shopify’s Dev Degree program. Before entering the program, she completed a horticulture co-diploma, finished high school and the required math courses, and pursued computer science while needing to pay her mortgage and maintain work-life balance. Dev Degree’s training path and rotating placements exposed her to computer science fundamentals, pair programming, Ruby on Rails on the orders team, infrastructure security, and network foundations, leading her to discover a strong interest in cyber security and cloud infrastructure. After graduating in September 2021, she joined Infrastructure Security full-time and later reports projects, internal security talks, a promotion to Senior Infrastructure Engineer, and Kubernetes contributions including a contributor award.


### [Making Your React Native Gestures Feel Natural](https://yomu.fyi/post/making-your-react-native-gestures-feel-natural.md)
- Company: [Shopify](https://yomu.fyi/company/shopify.md)
- Author: 2023-10-18
- Published: Jan 20, 2023
- Type: Tutorial

The post describes techniques for making draggable elements in a React Native Sheet component feel more natural during open-and-close gestures. A gesture handler updates yPosition as the user’s finger moves, then chooses an open or closed destination when the drag ends, but a position-only decision can ignore a fast flick and a fixed 600 ms animation ignores distance. The revised interaction adds event.velocityY, weighted by a multiplier, to the destination decision and uses withSpring so distance and release velocity affect the animation. It also divides overdrag distance when the Sheet is already open, creating resistance that communicates the boundary, and reports that flicks become easier while movement feels more realistic; the examples are ultimately recommended for testing on a real device.


### [Ruby 3.2’s YJIT is Production-Ready](https://yomu.fyi/post/ruby-3-2-s-yjit-is-production-ready.md)
- Company: [Shopify](https://yomu.fyi/company/shopify.md)
- Author: 2023-10-18
- Published: Jan 17, 2023
- Type: Announcement

Ruby 3.2 makes YJIT, Shopify’s just-in-time compiler for CRuby, substantially more suitable for production after its experimental Ruby 3.1 release. The project was ported from C99 to Rust for stronger safety guarantees and better abstractions, while memory work reduced overhead to approximately one third of the Ruby 3.1 level through metadata optimization, machine-code garbage collection, and lazy page allocation. YJIT 3.2 speeds railsbench by about 38% over the Ruby 3.2 interpreter, or 57% over the Ruby 3.1.3 interpreter, and adds native ARM64 support for Apple M1/M2, AWS Graviton, and Raspberry Pi. Shopify has deployed it across its Storefront Renderer infrastructure, measuring real-world speedups of 5% to 10%, while identifying memory footprint and method-call optimization as continuing priorities.


### [How Good Documentation Can Improve Productivity](https://yomu.fyi/post/how-good-documentation-can-improve-productivity.md)
- Company: [Shopify](https://yomu.fyi/company/shopify.md)
- Author: 2023-10-18
- Published: Jan 12, 2023
- Type: Explainer

Internal documentation is presented as a productivity and scaling tool for engineering organizations, especially as people move between teams, projects, or companies and remote work makes writing a default channel for knowledge sharing. Shopify’s approach combines standardized writing practices with three primary locations: Markdown microsites built with Docusaurus, internal GitHub for issues, READMEs, setup guidance, and searchable code, and the Vault, a GitHub- and Markdown-powered source of contextual information. The article argues that documentation should be treated as a product: it should be searchable, user-friendly, kept fresh, integrated into CI/CD, and hosted where engineers already work. It also recommends making writing routine through small contributions, paired writing, peer review, and audience-aware context, concluding that accessible documentation speeds onboarding, reduces duplicated problem-solving, supports asynchronous and cross-team collaboration, and improves developer literacy.


### [Catching Anomalies Early in Mobile App Releases](https://yomu.fyi/post/catching-anomalies-early-in-mobile-app-releases.md)
- Company: [Nextdoor](https://yomu.fyi/company/nextdoor.md)
- Author: Walt Leung
- Published: Jan 11, 2023
- Type: Problem & solution

Nextdoor deploys weekly mobile updates across iOS and Android using phased rollouts starting at 1% adoption to minimize blast radius. Standard aggregate observability cannot reliably detect early regressions because early adopters skew significantly more active than average users, obscuring silent drops in overall metric noise. To overcome this selection bias, Nextdoor built App Release Anomaly Detection using difference-in-differences causal inference. The methodology verifies pre-adoption trends with standard deviation bounds and fits a linear regression model to estimate the effect against an unobserved counterfactual. During a rollout of iOS version v1.234.5, this model identified a statistically significant app session decline at 1% adoption, isolating the regression 10 days earlier than week-over-week metrics.


### [From Ruby to Node: Overhauling Shopify’s CLI for a Better Developer Experience](https://yomu.fyi/post/from-ruby-to-node-overhauling-shopify-s-cli-for-a-better-developer-exp.md)
- Company: [Shopify](https://yomu.fyi/company/shopify.md)
- Author: 2023-10-18
- Published: Jan 10, 2023
- Type: Problem & solution

Shopify rewrote its unified CLI from Ruby to TypeScript running on Node after growing dependencies on Node tooling, Hydrogen’s preference for npm-managed dependencies, and a broader fit with web technologies. The rewrite aims to reduce system requirements, improve terminal consistency, and make contribution easier, while using a modular architecture of domain NPM packages built on @shopify/cli-kit. The team established shared code, UI, convention, and principle foundations, addressed cross-OS support, used TypeScript for stronger contracts, and applied Cucumber for end-to-end testing. The Node CLI unified and streamlined app development and added extensibility such as functions, but Theme commands still use Ruby and removing that dependency remains future work.


### [Building Obsidian, Tinder’s Design System](https://yomu.fyi/post/building-obsidian-tinder-s-design-system.md)
- Company: [Tinder](https://yomu.fyi/company/tinder.md)
- Author: Tinder
- Published: Jan 9, 2023
- Type: Problem & solution

As Tinder scaled over a decade, maintaining visual consistency across its client applications became unsustainable and increased engineering overhead. To address this, the UI Platform team developed Obsidian, a unified design system combining design tokens, reusable components, and documentation. Designers define base and context tokens in Figma using the Tokens Studio plugin, which are then transformed by Style Dictionary into native artifacts for iOS, Android, and Web. Web developers integrate these tokens using Atomizer to generate static stylesheets, while a Zeroheight documentation portal and a custom token lookup tool assist legacy migrations. The ongoing migration has streamlined collaboration between designers and engineers, resolved styling ambiguities, and improved color contrast accessibility across platforms.


### [Supabase Beta December 2022](https://yomu.fyi/post/supabase-beta-december-2022.md)
- Company: [Supabase](https://yomu.fyi/company/supabase.md)
- Author: ant\_wilson
- Published: Jan 5, 2023
- Type: Announcement

Supabase's December 2022 beta update recaps Launch Week 6, Community Day, Postgres ecosystem work, and other recent releases. The announcements include redesigned documentation rebuilt with Next.js; Storage v2 features for image resizing, webhooks, and a Smart CDN; and multi-factor authentication with optional enforcement through Row Level Security. Supabase Wrappers extend PostgreSQL Foreign Data Wrappers to query external databases, systems, and third-party APIs using SQL, while The Vault enters beta for encrypted secrets and stored data. The update also announces custom domains, point-in-time recovery, SSO on the dashboard in preparation for SAML, and ecosystem projects including pg\_graphql v1.0, a PostgREST 11 pre-release, and an experimental pg\_crdt extension.


### [Graph service platform](https://yomu.fyi/post/graph-service-platform.md)
- Company: [Grab](https://yomu.fyi/company/grab.md)
- Author: Wenxiang Lu
- Published: Jan 5, 2023
- Type: Problem & solution

Grab's GrabDefence team required a dedicated graph infrastructure to proactively identify mobile fraud patterns, such as multiple accounts operating on shared physical devices and suspicious financial loops. To address this, the team built a four-layer Platform as a Service that encapsulates graph database operations behind uniform RESTful APIs for OLTP search and OLAP analysis. The architecture utilizes Amazon S3 for raw data files, Amazon Neptune for graph storage, DynamoDB for schema and metadata configurations, and Kafka for streaming ingestion. When users trigger data loading tasks, the service validates entity attributes against schemas stored in DynamoDB before importing records into Neptune. This infrastructure allows investigators to traverse adjacent account IDs and visualize complex entity relationships without managing underlying database runtimes.


### [Reliving Your Happiest HTTP Interactions with Ruby’s VCR Gem](https://yomu.fyi/post/reliving-your-happiest-http-interactions-with-ruby-s-vcr-gem.md)
- Company: [Shopify](https://yomu.fyi/company/shopify.md)
- Author: 2023-10-18
- Published: Jan 5, 2023
- Type: Tutorial

Ruby’s VCR library records HTTP interactions and replays them in test suites, verifying requests and returning predictable responses; the post presents it as a way to manage complex WebMock stubs and multi-step or unreliable API behavior. It contrasts recordings from a live API with manually authored stubs: cassettes preserve observed behavior at recording time but are harder to change and do not update when the API changes. The guidance covers VCR.use\_cassette, configurable request matching, YAML cassettes, before\_filter logging, filter\_sensitive\_data, and safer recording modes such as :once and :none instead of :new\_episodes. It recommends VCR for integration-focused tests involving unpredictable sequences, multiple calls, or troublesome APIs, while favoring WebMock or decomposition for simple calls and specific states; cassette isolation and inspection add debugging value but can hide interactions.


### [WAL Mode in LiteFS](https://yomu.fyi/post/wal-mode-in-litefs.md)
- Company: [Fly.io](https://yomu.fyi/company/fly-io.md)
- Published: Jan 4, 2023
- Type: Announcement

LiteFS v0.3.0 adds support for SQLite’s write-ahead log (WAL) alongside the previously supported rollback journal, allowing its distributed file system to replicate transactions from either journaling mode. The post explains how rollback journals and WAL differ, then shows how LiteFS observes filesystem calls, identifies changed pages, and emits a common LTX change-set format; in WAL mode, the final frame’s commit field marks transaction completion. Replica nodes validate LTX files, acquire SQLite-compatible locks, and apply the changes, while the new litefs import command transactionally replaces a database for bootstrapping or snapshot reversion. Version 0.3.0 also replaces previous-page checksum tracking with a per-page checksum map, costing about 3 MB of RAM per gigabyte and roughly 5 ms of CPU time per gigabyte per commit, and adds a trace log whose enabled use can double disk I/O.


### [Launch Week 6 Hackathon Winners](https://yomu.fyi/post/launch-week-6-hackathon-winners.md)
- Company: [Supabase](https://yomu.fyi/company/supabase.md)
- Author: andrew\_smith,tyler\_shukert
- Published: Jan 3, 2023
- Type: Announcement

Supabase announced the winners of its sixth hackathon, held during Launch Week 6 after ending 2022 with many feature releases. Projects were judged across categories including Best Overall, Most Fun/Interesting, Best Flutter, Best Storage, and Best Edge Functions, with Deno participating in judging the edge category. Depulso, a CLI and web app for static site deployments with per-deployment .depulso.site subdomains and SSL, won Best Overall, while Supa SQL App was runner-up for converting human language into SQL queries. Other winners included HTTP Sense, a reverse proxy and network monitoring tool; supaquiz, a realtime multiplayer trivia game; Lookout, a metadata-based image discovery app; and Vista, a video transcoder that adds customizable subtitles from audio. Winners received keyboards or swag, and a Discord event was scheduled for January 5 at 7:00 AM PST.


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