Holy on Dev

How (and why) do you use React.forwardRef in Fulcro?

Welcome to the Holy Dev newsletter, which brings you gems I found on the web, updates from my blog, and a few scattered thoughts.

Imagine you have a list of things to display in your UI.

Welcome to the Holy Dev newsletter, which brings you gems I found on the web, updates from my blog, and a few scattered thoughts.

Welcome to the Holy Dev newsletter, which brings you gems I found on the web, updates from my blog, and a few scattered thoughts.

Welcome to the Holy Dev newsletter, which brings you gems I found on the web, updates from my blog, and a few scattered thoughts.

Welcome to the Holy Dev newsletter, which brings you gems I found on the web, updates from my blog, and a few scattered thoughts.

Having a pure function, what makes it more or less "functional" (as in "functional programming")?

Welcome to the very first issue of Holy Dev newsletter, which brings you gems I found on the web, updates from my blog, and a few scattered thoughts.

A decision tree to help you go from a problem to the most appropriate troubleshooting steps.

My professional year 2021 has been a year of Fulcro and Clojure.

Babashka is a lightning-fast Clojure scripting tool with batteries included.

An important feature of Ardoq is that multiple users can edit the same model, i.e. a directed multi-graph.

When I started with Clojure, I saw a language.

n 2016, the Clojure core team announced Clojure Spec, the most important addition to Clojure since v1.0.0.

If you want your blog’s tag list to also show the tags' frequency, what is better?

This article is about "the death [of productivity] by thousand cuts" - about the many obstacles that make enterprise development unnecessarily slow, costly, and painful.

Our Java and Spring webapp may take 5-10 min to restart after a change on my PC, especially when something else (such as IntelliJ) is using the CPU.

Fulcro’s stateful components serve normally both as elements of the UI and to define the data model, i.e. data entities with their unique IDs and attributes.

The Gradle application plugin provides you with a run task to run your Java application (provided you have set the mainClassName).

What makes a great team?

Once upon a time, the Spring Framework provided a much more lightweight and flexible solution than J2EE.

An extended transcript of my talk at DevFest Norway 2020 (slides here).Do you also love creating useful (web)apps and get easily frustrated by any friction in the development process?

Once again I have wasted 1-2 hours trying to figure out where the damn "403 Forbidden" was coming from.

I present three ways of detecting, handling, and showing server-side errors: globally and at the component level.By default, Fulcro considers only non-200 HTTP status as an error.

Terraform - the popular infrastructure as code tool and language - looks very appealing at start and many people swear by it.

Originally published at the Telia Engineering BlogA month ago I have started learning Rust and would like to share my impressions, the good things I have appreciated, and the things I have struggled with.

How to share a 3GB archive with a remote client when both might have unreliable connection that doesn’t keep up for the full download?

This has been a year of Clojure (and DevOps).

Error handling is something that core.async leaves to you (because it depends on your particular use case).

Clojure Zippers is a library for navigating and modifying tree data structures.

You are running a Clojure microservice on AWS Fargate in a private VPC subnet and want to have a secure REPL access to it, only exposing the port inside the VPC.

A year ago I have moved my blog from Wordpress and its WYSIWYG editor to a static site written using React and GaphQL and generated by Gatsby, with entries in Markdown, hosted on Netlify.

Sometimes the only way to get REPL into your production application is to tunnel it over HTTP. nREPL has a transport and Ring handler for that provided by Drawbridge.

So you have just deployed your Docker container to AWS Fargate but it keeps on restarting with the event “service XYZ (..) is unhealthy ..” and you have no idea why.

On a calm autumn morning we got a desperate call from our customer service.

I want to split my application uberjar into a separate JAR with only the dependencies and a JAR with only the application code so that I can upload them as separate “layers” and thus leverage layer caching.

When I was deciding what new language to learn, I could have picked the quite familiar Scala but chose instead Clojure - not despite of its lack of object-orientation, its immutable data structures, its too many parentheses on a single line - but because…

The big struggle when entering a new code base is distinguishing the essential business logic from the incidental aspect of how it is implemented.

Once upon time, an API returned 0.5 GB JSON and our server crashed.

Having the computer generate tests for you, trying tens of devious inputs you would never have thought of, is awesome.

Common mistakes made by Clojure beginners and style recommendations.

Me: Simple!

During our regular “tech lunch,” we have got our brains blown by the talk Lucas Cavalcanti & Edward Wible - Exploring four hidden superpowers of Datomic (slides) that summarizes the key benefits a startup bank in Brazil got from using this revolutionary d…

How to translate the concepts and patterns we know from enterprise Java applications to Clojure?

I have just gone through the painful experience of troubleshooting a remote Java webapp in a production-like environment and longed for Clojure’s explore-and-edit-running-app REPL.

In Clojure we use again and again the same data structures and have many functions operating on them.

As a Clojure developer thrown into an “enterprise” Java/Spring/Groovy application, I have a unique opportunity to experience and think about the differences between functional (FP) and object-oriented programming (OOP) and approach to design.

“It will only take about an hour,” I said to her.

(Published originally at the Telia Engineering blog.)We have a Java/Groovy Spring Boot webapp, mainly running a bunch of batch jobs fetching, transforming and combining data.