TypeScript

We just launched the Segment Config API (try it out for yourself here) — a set of public REST APIs that enable you to manage your Segment configuration. Behind the scenes the Config API is built with Go , GRPC and Envoy.

At Segment, we build new services in Go by default. The language is simple so new team members quickly ramp up on a codebase. The tool chain is fast so developers get immediate feedback when they break code, tests or integrations with other systems. The runtime is fast so it performs great at scale.

For the newest round of APIs we adopted the GRPC service #framework.

The Protocol Buffer service definition language makes it easy to design type-safe and consistent APIs, thanks to ecosystem tools like the Google API Design Guide for API standards, uber/prototool for formatting and linting .protos and lyft/protoc-gen-validate for defining field validations, and grpc-gateway for defining REST mapping.

With a well designed .proto, its easy to generate a Go server interface and a TypeScript client, providing type-safe RPC between languages.

For the API gateway and RPC we adopted the Envoy service proxy.

The internet-facing segmentapis.com endpoint is an Envoy front proxy that rate-limits and authenticates every request. It then transcodes a #REST / #JSON request to an upstream GRPC request. The upstream GRPC servers are running an Envoy sidecar configured for Datadog stats.

The result is API #security , #reliability and consistent #observability through Envoy configuration, not code.

We experimented with Swagger service definitions, but the spec is sprawling and the generated clients and server stubs leave a lot to be desired. GRPC and .proto and the Go implementation feels better designed and implemented. Thanks to the GRPC tooling and ecosystem you can generate Swagger from .protos, but it’s effectively impossible to go the other way.

Our first experience with .NET core was when we developed our OSS feature management platform - Tweek (https://github.com/soluto/tweek). We wanted to create a solution that is able to run anywhere (super important for OSS), has excellent performance characteristics and can fit in a multi-container architecture. We decided to implement our rule engine processor in F# , our main service was implemented in C# and other components were built using JavaScript / TypeScript and Go.

Visual Studio Code worked really well for us as well, it worked well with all our polyglot services and the .Net core integration had great cross-platform developer experience (to be fair, F# was a bit trickier) - actually, each of our team members used a different OS (Ubuntu, macos, windows). Our production deployment ran for a time on Docker Swarm until we've decided to adopt Kubernetes with almost seamless migration process.

After our positive experience of running .Net core workloads in containers and developing Tweek's .Net services on non-windows machines, C# had gained back some of its popularity (originally lost to Node.js), and other teams have been using it for developing microservices, k8s sidecars (like https://github.com/Soluto/airbag), cli tools, serverless functions and other projects...

One TypeScript / Angular 2 code health recommendation at Google is how to simplify dealing with RxJS Observables. Two common options in Angular are subscribing to an Observable inside of a Component's TypeScript code, versus using something like the AsyncPipe (foo | async) from the template html. We typically recommend the latter for most straightforward use cases (code without side effects, etc.)

I typically review a fair amount of Angular code at work. One thing I typically encourage is using plain Observables in an Angular Component, and using AsyncPipe (foo | async) from the template html to handle subscription, rather than directly subscribing to an observable in a component TS file.

Subscribing in components

Unless you know a subscription you're starting in a component is very finite (e.g. an HTTP request with no retry logic, etc), subscriptions you make in a Component must:

1. Be closed, stopped, or cancelled when exiting a component (e.g. when navigating away from a page),
2. Only be opened (subscribed) when a component is actually loaded/visible (i.e. in ngOnInit rather than in a constructor).

AsyncPipe can take care of that for you

Instead of manually implementing component lifecycle hooks, remembering to subscribe and unsubscribe to an Observable, AsyncPipe can do that for you.

I'm sharing a version of this recommendation with some best practices and code samples.

#Typescript #Angular #RXJS #Async #Frontend

The front end for Heap begun to grow unwieldy. The original jQuery pieces became difficult to maintain and scale, and a decision was made to introduce Backbone.js, Marionette, and TypeScript. Ultimately this ended up being a “detour” in the search for a scalable and maintainable front-end solution. The system did allow for developers to reuse components efficiently, but adding features was a difficult process, and it eventually became a bottleneck in advancing the product.

Today, the Heap product consists primarily of a customer-facing dashboard powered by React, MobX, and TypeScript on the front end. We wrote our migration to React and MobX in detail last year here.

#JavascriptUiLibraries #Libraries #JavascriptMvcFrameworks #TemplatingLanguagesExtensions

The client-side stack of Shopify Admin has been a long journey. It started with HTML templates, jQuery and Prototype. We moved to Batman.js, our in-house Single-Page-Application framework (SPA), in 2013. Then, we re-evaluated our approach and moved back to statically rendered HTML and vanilla JavaScript. As the front-end ecosystem matured, we felt that it was time to rethink our approach again. Last year, we started working on moving Shopify Admin to React and TypeScript.

Many things have changed since the days of jQuery and Batman. JavaScript execution is much faster. We can easily render our apps on the server to do less work on the client, and the resources and tooling for developers are substantially better with React than we ever had with Batman.

#FrameworksFullStack #Languages

I needed to choose a full stack of tools for cross platform mobile application design & development. After much research, trying different tools, and many years of mobile and web software design & development, these are what I came up with that work for me today:

For the client coding I chose Framework7 because of its performance, easy learning curve, and very well designed, beautiful UI widgets. I think it's perfect for solo development or small teams. I didn't like React Native. It felt heavy to me and rigid. Framework7 allows the use of #CSS3, which I think is the best technology to come out of the #WWW movement. No other tech has been able to allow designers and developers to develop such flexible, high performance, customisable user interface elements that are highly responsive and hardware accelerated before. Now #CSS3 includes variables and flexboxes it is truly a powerful language and there is no longer a need for preprocessors such as #SCSS / #Sass / #less. React Native contains a very limited interpretation of #CSS3 which I found very frustrating after using #CSS3 for some years already and knowing its powerful features. The other very nice feature of Framework7 is that you can even build for the browser if you want your app to be available for desktop web browsers. The latest release also includes the ability to build for #Electron so you can have MacOS, Windows and Linux desktop apps. This is not possible with React Native yet.

Framework7 runs on top of Apache Cordova. Cordova and webviews have been slated as being slow in the past. Having a game developer background I found the tweeks to make it run as smooth as silk. One of those tweeks is to use WKWebView. Another important one was using srcset on images.

I use #Template7 for the templating system which is a no-nonsense mobile-centric #HandleBars style extensible templating system. It's easy to write custom helpers for, is fast and has a small footprint. I'm not forced into a new paradigm or learning some new syntax. It operates with standard JavaScript, HTML5 and CSS 3. It's written by the developer of Framework7 and so dovetails with it as expected.

JavaScript is very far from my ideal language. To make life bearable I configured TypeScript to work with the latest version of Framework7. This makes me feel like I'm back in the good old Java days, but with more flexibility. I consider TypeScript to be one of the rare best creations to come out of Microsoft in some time. They must have an amazing team working on it. It's very powerful and flexible.

For the user interface design and prototyping I use Figma. Figma has an almost identical user interface to Sketch but has the added advantage of being cross platform (MacOS and Windows). Its real-time collaboration features are outstanding and I use them a often as I work mostly on remote projects. Clients can collaborate in real-time and see changes I make as I make them. The clickable prototyping features in Figma are also very well designed and mean I can send clickable prototypes to clients to try user interface updates as they are made and get immediate feedback. I'm currently also evaluating the latest version of #AdobeXD as an alternative to Figma as it has the very cool auto-animate feature. It doesn't have real-time collaboration yet, but I heard it is proposed for 2019.

For the UI icons I use Font Awesome Pro. They have the largest selection and best looking icons you can find on the internet.

For the backend I chose Graphcool Framework. It has great customer support and a very accessible free startup plan for working on new projects. I was never a fan of relational databases so I'm very pleased to see NoSQL / GraphQL databases coming to the fore and I'm happy to use them. No more server side API development required! NoSQL databases are so much more flexible and the way I think databases were meant to be from the start. GraphQL still has some way to go in order to provide the full power of a mature graph query language like #Cypher, but I'm still enjoying it in its current incarnation.

For the IDE I use Visual Studio Code which is blazingly fast and silky smooth for editing code, and integrates seamlessly with TypeScript for the ultimate type checking setup (both products are produced by Microsoft).

I use Webpack and Babel to compile the JavaScript. TypeScript can compile to JavaScript directly but Babel offers a few more options and polyfills so you can use the latest (and even prerelease) JavaScript features today and compile to be backwards compatible with virtually any browser. My favorite recent addition is "optional chaining" which greatly simplifies and increases readability of a number of sections of my code dealing with getting and setting data in nested objects.

I use some Ruby scripts to process images with ImageMagick and pngquant to optimise for size and even auto insert responsive image code into the HTML5. Ruby is the ultimate cross platform scripting language. Even as your scripts become large, Ruby allows you to refactor your code easily and make it Object Oriented if necessary. I find it the quickest and easiest way to maintain certain aspects of my build process.

I use PhoneGap when testing the app. It auto-reloads your app when its code is changed and you can also install it on Android phones to preview your app instantly. iOS is a bit more tricky cause of Apple's policies so it's not available on the App Store, but you can build it and install it yourself to your device.

So that's my latest mobile stack. What tools do you use? Have you tried these ones?