---
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

### [ShipIt! Presents: How Shopify Uses Nix](https://yomu.fyi/post/shipit-presents-how-shopify-uses-nix.md)
- Company: [Shopify](https://yomu.fyi/company/shopify.md)
- Author: 2023-10-18
- Published: May 29, 2020
- Type: Explainer

At a May 25, 2020 ShipIt! event, Shopify presented how it uses Nix to rebuild developer tooling and demonstrate the tools used day to day. The follow-up answers questions about runix and lorri interoperability, CI/CD, Ketos, remote-work download costs, dependency management, and pinned nixpkgs revisions. Shopify says its tooling is optimized for build workflows rather than development, so it spent substantial effort adapting bundleEnv/bundleApp to its preferred workflow and hopes to upstream the solution. Nix is not yet used for CI/CD; gems prompted the initial Nix work, while Node modules are not yet managed with Nix, and a project-specific nixpkgs revision is enforced whenever dev up runs.


### [Fly - Now With Power Pause](https://yomu.fyi/post/fly-now-with-power-pause.md)
- Company: [Fly.io](https://yomu.fyi/company/fly-io.md)
- Published: May 28, 2020
- Type: Announcement

Fly introduces Power Pause, a way to mothball applications when development pauses, schedules slip, or running costs need management. The new flyctl suspend command saves an application's state and reduces its running instances to zero while retaining networking configuration, IP addresses, and certificates; flyctl resume restores service by starting one instance first, even for applications deployed across multiple regions. Operators can then use flyctl scale set min=n to increase the minimum count, while flyctl regions list shows the region pool and the new regions set command replaces manual region additions and deletions. The release also adds application status to account listings and a flyctl open command that opens a deployed application's hostname in a browser.


### [7 Ways to Make Your SQL Workshop Beginner-friendly](https://yomu.fyi/post/7-ways-to-make-your-sql-workshop-beginner-friendly.md)
- Company: [Shopify](https://yomu.fyi/company/shopify.md)
- Author: 2023-10-18
- Published: May 21, 2020
- Type: Tutorial

Shopify’s 90-minute SQL workshop serves new RnD hires with varied technical backgrounds, including participants who may have no experience with databases or programming. It separates beginners from intermediate learners and aims to help beginners use data responsibly to discover insights. The beginner format spends its first 30 minutes on data warehouse architecture, data preparation, and privacy, then uses real production data and tools such as Mode Analytics with an accessible dataset. The curriculum identifies core SQL objectives, translates them into practical questions, starts with SELECT \* exploration, and builds queries toward a larger analytical question. It also provides beginner, intermediate, and advanced learning resources covering topics from foundational clauses and aggregations to joins, window functions, CTEs, and Presto-specific techniques.


### [WebSockets and Fly](https://yomu.fyi/post/websockets-and-fly.md)
- Company: [Fly.io](https://yomu.fyi/company/fly-io.md)
- Published: May 20, 2020
- Type: Tutorial

Fly supports WebSocket connections, and the post demonstrates that support with flychat-ws, a small chat application built from raw WebSockets and Express. Deployment requires cloning the example, running npm install, then using flyctl init, flyctl deploy, and flyctl open, with no application-specific configuration changes. Its fly.toml maps internal TCP port 8080 to HTTP port 80 and TLS/HTTP port 443, sets concurrency limits of 20 soft and 25 hard, and checks the service every 10 seconds with a two-second timeout. The Node server broadcasts each received message to every connected client, while the browser selects ws or wss from the served protocol and sends JSON messages. TLS terminates at Fly’s network edge, and the app can also run locally or in Docker.


### [Mux, Fly, Wocket and RTMP](https://yomu.fyi/post/mux-fly-wocket-and-rtmp.md)
- Company: [Fly.io](https://yomu.fyi/company/fly-io.md)
- Published: May 19, 2020
- Type: Tutorial

Wocket is a proof-of-concept application for sending live video from a browser to an RTMP server, potentially avoiding a local encoder such as OBS or Ecamm Live. Built with Next.js and a custom WebSocket server, it captures webcam video, renders it onto a canvas, and uses ffmpeg to support streaming to a Mux live stream through an RTMP ingest URL. The post documents local setup with npm, production commands, and deployment to Fly.io via flyctl and a Dockerfile, while noting that ffmpeg must be available on the PATH. The intended integration uses the MediaRecorder API to send video when dataavailable fires. Mux test streams are limited to five minutes, watermarked, and deleted after 24 hours when no credit card is entered, and the author cautions against relying on the demo for important production workloads.


### [What Is Nix](https://yomu.fyi/post/what-is-nix.md)
- Company: [Shopify](https://yomu.fyi/company/shopify.md)
- Author: 2023-10-18
- Published: May 19, 2020
- Type: Explainer

Nix is presented as a way to make software’s usually implicit dependency graph explicit, motivated by the difficulty of quickly conveying its concepts and by Shopify’s ongoing use of it to rebuild developer tooling. Its core model has four building blocks: the immutable Nix Store, derivations, sandboxing, and the Nix language. The Store acts as a graph database whose nodes are immutable files or directories, while path hashes and embedded references represent dependencies and support transitive-closure queries. Derivations record build instructions and explicitly named inputs; the Nix language evaluates these descriptions and has essentially one side effect, creating derivation files, leaving other tools to build outputs. Nixpkgs is described as a lazily evaluated Nix program containing many derivations, and the article concludes with introductory resources and a discussion of Shopify’s use of Nix.


### [Fly Changelog May 15th 2020](https://yomu.fyi/post/fly-changelog-may-15th-2020.md)
- Company: [Fly.io](https://yomu.fyi/company/fly-io.md)
- Published: May 15, 2020
- Type: Announcement

Fly’s May 15, 2020 changelog records changes to the Fly platform, flyctl, and related websites since the previous update. The main release was a new scaling system based on region pools, accompanied by new scaling commands in flyctl 0.0.122; the earlier autoscale command from version 0.0.121 was removed. The platform also rolled out an HTTP2-only backhaul for traffic between the Fly edge and datacenters, with the changelog reporting improved performance and stability for applications using the http handler. Other entries document new autoscale and regions commands in 0.0.121, consistent naming for flyctl binary artifacts, removal of references to 32-bit Windows and Linux builds during deprecation, and a fix for custom Dockerfile mapping.


### [Deno on Fly](https://yomu.fyi/post/deno-on-fly.md)
- Company: [Fly.io](https://yomu.fyi/company/fly-io.md)
- Published: May 14, 2020
- Type: Tutorial

Deno on Fly explains how to package and deploy a Deno 1.0 application using a Dockerfile rather than a buildpack. The example uses the hellodeno-dockerfile project, with an Alpine Linux and Deno 1.0.0 base image, port 8080, a non-root deno user, and separate dependency and application caching layers. A deps.ts file pins imported package versions, while the Dockerfile runs deno cache deps.ts and deno cache server.ts before starting server.ts with deno run --allow-net server.ts. After local Docker testing, the deployment flow uses flyctl init to create the Fly app and fly.toml, then flyctl deploy to build and push the image. The resulting application is available at a Fly hostname, with HTTP and TLS routing to port 8080, automatic HTTPS redirection, and the option to scale globally and add domains with generated certificates.


### [A Brief History of TLS Certificates at Shopify](https://yomu.fyi/post/a-brief-history-of-tls-certificates-at-shopify.md)
- Company: [Shopify](https://yomu.fyi/company/shopify.md)
- Author: 2023-10-18
- Published: May 14, 2020
- Type: Explainer

Shopify’s TLS certificate infrastructure evolved from a handful of manually renewed certificates for administration and checkout traffic to an automated system supporting more than 1M merchants. The initial Shopify Plus implementation added domains to shared Subject Alternative Name (SAN) certificates, but manual provisioning, certificate-authority limits, extra IP requirements, and the inability to rely on SNI made the approach labor-intensive and error-prone. Notary automated certificate-authority API requests, domain verification, delivery, and renewals, storing one certificate and unique private key per domain in a relational database. OpenResty Lua middleware dynamically loaded certificates through ssl\_certificate\_by\_lua, while an in-memory LRU cache reduced handshake latency; theme processing replaced HTTP asset references to prevent mixed-content warnings. After reaching all-merchant encrypted storefronts in February 2016, Shopify migrated much of its certificate use to Let’s Encrypt and later a cloud edge, ultimately returning to Notary-issued certificates uploaded to both edge networks to simplify synchronization.


### [Updating Scale](https://yomu.fyi/post/updating-scale.md)
- Company: [Fly.io](https://yomu.fyi/company/fly-io.md)
- Published: May 13, 2020
- Type: Announcement

Fly introduces a new scaling model and command set intended to simplify how applications distribute instances across regions and manage global load. Instead of assigning instance counts to a fixed regional list, the system uses a pool of allowed regions plus global minimum and maximum instance counts, with Standard and Balanced models determining placement. Standard distributes instances evenly through the minimum and adds demand-driven instances without relocating them, while Balanced can move instances from other regions once the maximum is reached to match regional demand. The new flyctl regions command manages the pool, and flyctl scale show, standard, balanced, set, and vm commands configure or inspect scaling mode, counts, and VM size. Regional allocation can still fall back to a nearby region when the selected region cannot create an instance.


### [Dev Degree: Behind the Scenes](https://yomu.fyi/post/dev-degree-behind-the-scenes.md)
- Company: [Shopify](https://yomu.fyi/company/shopify.md)
- Author: 2023-10-18
- Published: May 13, 2020
- Type: Explainer

Dev Degree is Shopify’s work-integrated learning program, designed to combine an accredited computer science degree with four years of continuous developer experience. Students take three university courses per semester while working 25 hours weekly, beginning with Shopify-led skills training before moving through four team placements across disciplines such as back-end, front-end, data, security, and production engineering. The program teaches tools and technologies including Git and GitHub, Ruby, Rails, React, TypeScript, and GraphQL, while emphasizing mentorship, feedback, personal development, and support from a multidisciplinary team working with university partners. The first cohort graduated on April 24, 2020, after adapting to program changes and remote learning during the pandemic; the post reports that 100% of graduates accepted full-time positions within six months.


### [How to Fix Slow Code in Ruby](https://yomu.fyi/post/how-to-fix-slow-code-in-ruby.md)
- Company: [Shopify](https://yomu.fyi/company/shopify.md)
- Author: 2023-10-18
- Published: May 8, 2020
- Type: Tutorial

Performance regressions can accumulate in a large monolithic Rails application, making it difficult to identify offending changes among thousands of daily commits. The post presents profiling and benchmarking as complementary practices: profiling locates runtime bottlenecks, while benchmarking compares code paths and validates fixes. It covers elapsed time, CPU versus wall time, object allocations, TracePoint and ObjectSpace, plus rbspy, stackprof, rack-mini-profiler, and App Profiler, which supports on-demand remote production profiling at Shopify. A flamegraph example showed garbage collection consuming about 35% of CPU time in a slow request, and the team inferred excessive Ruby object allocation; a Rails benchmark showed roughly 50x improvement from caching an order’s total price calculation. The discussion cautions against micro-optimizations whose gains do not justify code changes and recommends addressing larger performance issues first.


### [Supabase Alpha April 2020](https://yomu.fyi/post/supabase-alpha-april-2020.md)
- Company: [Supabase](https://yomu.fyi/company/supabase.md)
- Author: Paul Copplestone
- Published: May 1, 2020
- Type: Announcement

The April 2020 alpha release of Supabase introduces developer tools designed to make Postgres as straightforward to use as Firebase. Users can configure a Postgres instance in less than two minutes and execute database queries directly from the dashboard interface. The platform provides auto-generated RESTful APIs along with auto-updating documentation created through database schema introspection. Development work also encompasses realtime listeners for database change subscriptions, query performance analysis tools, and connectors that route realtime updates to queues or webhooks. Supabase is not yet production ready, storing only GitHub usernames and emails while running for free under Digital Ocean's startup program.


### [Fly Changelog 1st May 2020](https://yomu.fyi/post/fly-changelog-1st-may-2020.md)
- Company: [Fly.io](https://yomu.fyi/company/fly-io.md)
- Published: May 1, 2020
- Type: Announcement

Fly’s 1 May 2020 changelog records enhancements to flyctl, a new Open Source page, and a revised load-balancing allocation algorithm. Version 0.0.117 added flyctl auth docker, allowing deployments of images directly to Fly by adding registry.fly.io to Docker’s authenticated registries, and introduced --image-label for selecting a specific image label at deployment time. The release also increased the timeout at the end of deployment monitoring to prevent erroneous “No Deployment” messages and changed deploy version negotiation to resolve API compatibility errors. For global applications with large numbers of instances, the new algorithm directs each incoming connection to an instance from the closest least-loaded service among three randomly selected healthy services in the app’s three nearest regions.


### [Evolving Alongside your Tech Stack](https://yomu.fyi/post/evolving-alongside-your-tech-stack.md)
- Company: [Heroku](https://yomu.fyi/company/heroku.md)
- Author: Chris Castle
- Published: Apr 30, 2020
- Type: Explainer

Rapid advances in software have expanded both what applications can do and what developers must understand, from efficient code to integration, security, and user experience. As tools make polished interfaces easier to build, engineers are expected to understand users, design sensibilities, system behavior, and constraints such as memory management and CPU load. The post recommends maintaining broad awareness of changing technologies while prioritizing learning around problems actually encountered; Postgres performance issues may warrant understanding traffic and write effects without exhaustive tuning. It cautions against adopting every new framework or database on reputation alone, using MemSQL as an example, and concludes that developers should evaluate trade-offs carefully, build expertise in the tools they operate, and focus on shipping meaningful product work.


### [Categorizing Products at Scale](https://yomu.fyi/post/categorizing-products-at-scale.md)
- Company: [Shopify](https://yomu.fyi/company/shopify.md)
- Author: 2023-10-18
- Published: Apr 30, 2020
- Type: Explainer

Shopify describes a product-categorization system for more than one billion products across the Google Product Taxonomy, which contains over 5,000 hierarchical categories. The model uses product titles, descriptions, collections, tags, vendors, and merchant-provided types, with text preprocessing and a fixed-length term-frequency HashingTF featurizer in PySpark rather than image features or vocabulary-based methods such as Word2Vec. Kesler’s Construction transforms multiclass training into a binary dataset by embedding each candidate class into feature tokens, while logistic regression provides a single, interpretable classifier that can use taxonomy relationships and reduce computational load. The resulting baseline supports more than 20 teams and downstream experiences, while schematized Kafka events and an internal annotation platform provide human feedback; the post identifies class imbalance, multilingual text, and image features as improvement areas.


### [Building and Scaling a Global Chatbot using Heroku + Terraform](https://yomu.fyi/post/building-and-scaling-a-global-chatbot-using-heroku-terraform.md)
- Company: [Heroku](https://yomu.fyi/company/heroku.md)
- Author: Garen Torikian
- Published: Apr 22, 2020
- Type: Problem & solution

Live Agent, Salesforce’s embeddable chatbot, must handle customer interactions and requests at global scale while remaining highly available across regions. Its eight-person team chose Heroku to avoid managing bare metal, cloud virtual machines, databases, and other third-party services, while relying on managed Java support and regional infrastructure. The platform runs ten apps with Heroku Postgres, Redis, and Apache Kafka dependencies, and deploys them inside Heroku Private Spaces to isolate network boundaries and data. Terraform defines and replicates apps, add-ons, custom domains, logging, and profiling configuration across regions, allowing changes to propagate through a pull request. The result described is a simpler operational model in which Heroku handles maintenance and the team can scale the same architecture into new geographic locations.


### [Developer Platform updates Spring 20'](https://yomu.fyi/post/developer-platform-updates-spring-20.md)
- Company: [Zoom](https://yomu.fyi/company/zoom.md)
- Author: Michael Purnell
- Published: Apr 21, 2020
- Type: Announcement

Zoom introduced several updates across its developer platform alongside new roadmap milestones for 2020. Marketplace enhancements include a Developer Dashboard tracking install numbers and API usage, as well as dynamic OAuth scope configurations that distinguish mandatory and optional permissions. For client development, the WebSDK adds Microsoft Edge Chromium compatibility with video and VOIP support, whereas the iOS SDK incorporates Xcode 11 support. Due to increased developer demand, Zoom updated its V2 REST API rate limits and delivered new chat webhooks tracking message, channel, and member activity. Upcoming platform initiatives include the permanent termination of all legacy V1 APIs on May 31, 2020, platform security enhancements, and an iframe-free JavaScript embedding framework for the WebSDK.


### [Imaginary on Fly, just One-click](https://yomu.fyi/post/imaginary-on-fly-just-one-click.md)
- Company: [Fly.io](https://yomu.fyi/company/fly-io.md)
- Published: Apr 20, 2020
- Type: Announcement

Fly announces a one-click launcher for Imaginary, an open-source image service that is among Fly’s popular global image-service use cases. The launcher is intended to let users create a running, production-ready version without infrastructure by pasting button code, and Imaginary’s creators added it to the project’s GitHub README. The post says users can get started with operations including converting and resizing images faster, while scalable SVG buttons are designed to work on pages. It also presents one-click launchers as a possible funding channel through revenue sharing and invites other open-source projects to help develop a process for launching applications on Fly.


### [Fly Changelog 17th April 2020](https://yomu.fyi/post/fly-changelog-17th-april-2020.md)
- Company: [Fly.io](https://yomu.fyi/company/fly-io.md)
- Published: Apr 17, 2020
- Type: Announcement

This changelog records updates to Fly’s infrastructure, flyctl tooling, and web experience during the week ending 17 April 2020. Version 0.0.116 improves diagnostics for invalid fly.toml files by listing problematic sections and settings, adds Homebrew upgrade instructions to the README, provides basic names for flyctl scale vm sizes, and packages flyctl for Arch Linux through flyctl-bin. On the platform, new applications receive their app.fly.dev certificate “instantly,” while Fly Proxy can serve replacement certificates two weeks before expiration when possible. The site also adds a dedicated ChangeLog page that consolidates recent entries, alongside an RSS feed containing changelog posts. The flyctl changes include contributions from Lars Lehtonen and Simon Willison.


[Newer posts](https://yomu.fyi/posts/page/232.md) · [Older posts](https://yomu.fyi/posts/page/234.md)