Generating tests from recorded data in Node.js
Fast ways to generate data to using in your testing. »
The writings of Ashley Davis on coding, data, visualization, microservices, game dev or whatever is exciting at the moment
Building robust data synchronization code in Node.js
Testing a complex non-determnistic data syncrhonization algorithm. »
Fuzz testing REST APIs in Node.js
Automating tests cases by generating sets valid and invalid data. »
Streamlined contract testing
Get the benefits of contract testing whilst avoiding the complexity. »
How to fail at microservices
Don’t hold off fixing problems until they become too big and difficult to manage. »
Effective Testing in JavaScript
Some surprising ways to be more effective at testing in JavaScript. »
Adding a Natural Language Interface to Your Application
In this article, learn how to add a natural language interface to your application and then extend the chatbot to voice commands. »
The False Dichotomy of Monolith vs Microservices
There is no one size fits all answer. Monoliths and microservices are not your only two choices. Find the balance that works for you. »
Creating separate monorepo CI/CD pipelines with GitHub Actions
Learn how to create separate CI/CD pipelines for microservices in a monorepo. So you can keep using the monorepo for much longer, but still have the flexiblity of independent deployment pipelines for your microservices. »
The quick guide to creating a production Kubernetes cluster (version 2)
For when you need a cloud-based Kubernetes cluster quickly! »
The quick guide to your local Kubernetes instance
Why create a Kubernetes cluster when you probably already have one locally. If you installed Docker Desktop you most likely have a local version of Kubernetes that you can simply switch on and start using! »
Automated testing for Algorand smart contracts, part 3
A three part series with techniques and tips on automated testing for Algorand smart contracts. »
Automated testing for Algorand smart contracts, part 2
A three part series with techniques and tips on automated testing for Algorand smart contracts. »
Automated testing for Algorand smart contracts, part 1
A three part series with techniques and tips on automated testing for Algorand smart contracts. »
Managing a full-stack, multi-package monorepo using pnpm
pnpm. What’s all the fuss about? Learn how you can use to share code between backend and frontend in a fullstack monorepo. »
Live reload across the stack
Live reload: What it is, why you need it, and how to do it across your entire stack »
Sharing TypeScript code between projects
Exploring effective ways to share TypeScript code between different projects. »
Keeping mistakes away from production
Developers make mistakes — we're human. In this post, you'll learn how to improve your review process and write better, mistake-free code. »
You’re wrong about singletons
Learn where singletons came from, where it all went wrong, and how you can best use singletons to reap their benefits. »
Streaming video in Safari: Why is it so difficult?
Why is it so difficult to implement video streaming for Safari? What does it take to make it work for Safari? The answers to these questions are revealed in this blog post. »
MiniQL: Building a query language in TypeScript
In this blog post, I’d like to introduce you to my new open-source project called MiniQL. We’ll also talk about why I reinvented the wheel and when it’s OK to do that. »
Roll your own dependency injection
How to roll your own dependency injection with TypeScript decorators and the JavaScript Proxy class — it’s easier than you think. »
Microservices for startups, part 2
The how-to guide to microservices for startups, small teams and solo developers. »
Microservices for startups, part 1
Startups can use microservices. Sortal is living proof. In this blog post I describe the microservices architecture behind Sortal, why we couldn't do without microservices and how as a startup we bootstrapped microservices in a cost effective way. »
Debugging async operations in Node.js
Building useful debugging tools from the Node.js async hooks API »
Computing time series volatility
This blog post shows how to compute percent volatility for time series data. »
Kubernetes log aggregation
The simplest possible starting point for scalable logging on your Kubernetes cluster »
The quick guide to creating a Kubernetes cluster
For when you need a new Kubernetes cluster quickly! »
What's wrong with the monolith?
The microservices architecture is an increasingly popular alternative to monolithic application development. But what is a monolith and what exactly is wrong with it? »
Crafting build pipelines with Docker
Learn how you can use a multi-stage Docker build for your Node.js application. »
Backtesting trading strategies with JavaScript
JavaScript can be used to do many things, including quantitative trading. In this post I show how to backtest a quantitative trading strategy with JavaScript. »
Node.js memory limits
Node.js has memory limitations that you can hit quite easily in production. You'll know this if you ever tried to load a large data file into your Node.js application. But where exactly are the limits of memory in Node.js? In this short post we'll push Node.js to it's limits to figure out where those limits are. We'll also cover some practical techniques you can use to work around the memory limitations and get your data to fit into memory. »
Node.js chart rendering with C3 and Nightmare
I've been doing a lot of data analysis in JavaScript. It makes sense for me to work in JavaScript, because I already use it and that's where my visualizations normally end up. JavaScript has a very rich ecosystem of visualization libraries so that's not surprising. All these visualization libraries are browser based... which is great if that's where you want your visualization to be. It's not so great if you just want to render a chart to an image, say to store for later or to include in some kind of report. »
Acquiring stock market data from Alpha Vantage
As a stock trader I need a ready of supply stock market data for analysis and visualisation. That data is needed for decision making and I often render it to a chart to better understand it. »
Graphing stock data with Highstock and Data-Forge
This is a revisit with various improvements to my original post on The Data Wrangler. In this post I show how to visualise stock data using Data-Forge and Highstock. I also demonstrate how to apply a simple moving average to the price data. »
Intraday price alert
Are you interested in stock trading but don't have time to watch prices all day? Why stare at the screen for hours on end when you can automate this kind of thing. This post talks about a small app I created to continuously and automatically detect when the price of particular companies have risen to specified levels. »
Automated internet speed testing
Do you have a slow internet? Need to visualize your internet speed over time? Do you want to know when outages are happening? »
Linear regression
Linear regression is a technique that is very useful when analysing the trajectory of a stock. In this post I'll show how to compute and render a linear regression trend line. »
Average true range
Average true range is an indicator that is useful for judging the volatility of a stock. I use this to set the level for my stop loss orders. In this post I'm going to show how to calculate and visualise average true range in JavaScript. »
Highstock + Data-Forge + Yahoo
In this first post on The Data Wrangler I show how to visualise financial data from the Yahoo API using Data-Forge and Highstock. I also demonstrate how to apply a simple moving average to the price data. »