In the previous post we started to look at how to implement a doodle using smart contracts written in DAML. The last code snippet we looked at was the IssueInvites choice, which is used to send out invites to each of the voters. …

In my previous post, DAML Smart Contracts Appetizer, I introduced the DAML smart contracts programming language and runtime and explained why I was so enthusiastic about it. I would now like to get into a slightly more complex example: a Doodle written in DAML. If you looked up DAML code…

Introduction I am very enthusiastic about DAML, and for good reason. DAML has a lot going for it: It’s a strongly typed, functional programming language, based on Haskell The language and its developer tools are open source It comes with a smart contract test framework DAML has private transactions out of…

I have recently published a small Java library on Maven Central: written in plain Java, built with Gradle using Gradle’s Kotlin DSL, integrated using GitHub actions and published to Maven Central using Gradle’s “maven-publish” plugin. Here are simple step-by-step instructions on how to reproduce and automate the process. Sonatype OSS Project Setup You will…

I am building a home climate monitoring system for my house. Active sensors are built around Raspberry Pi computers paired with AM2302 temperature / humidity sensors. The Raspberry Pis read humidity and temperature data from the sensors every minute, add metadata such as home id, room name, tenant ID —…

Non — blocking, asynchronous I/O APIs make your applications more resilient, responsive and cost effective. In this blog post we will look at the problems blocking I/O is causing, at how non-blocking I/O solves the problems and then apply these principles to the every-day use case of file uploading. Synchronous Blocking I/O Traditional…

The proxy based service mesh is an emerging technology that simplifies building distributed micro-services systems by using specialized proxies to provide cross-cutting infrastructure functionality such as service discovery, load balancing, circuit breaking, metrics monitoring, distributed tracing and more at container orchestration level. …

The Data Warehouse Definition The other day I was listening to a software engineering podcast. Don’t remember the exact title, but at some point the host asks the guest: “can you explain the difference between an operational database and a data warehouse?”. And the guest goes: “well, the operational database…

In my previous post, “A case for in-memory columnar data structures”, I used a JMH benchmark to show that if what we need to do is calculate statistical indicators over an object field ( metric ), destructuring data and store successive values of that metric in a continuous array is…