Oliver's Posts

Range queries in Firestore

Range queries in Firestore

I like Firestore because it's an easy-to-use database. Especially because it's easy to build queries that are just fast. It's designed to work at scale - by providing queries that have a constant time, regardless of the query conditions. But if you have worked with Firestore before, you will know that this limits the types of queries you can do. This can make range queries, for example for calendar applications, a challenge.

Scale re-orderable lists

Scale re-orderable lists

Creating a UI where a user can manually reorder items based on their needs is neat, but can be quite challenging to implement in the backend. One need to store the order of the items somehow. There are different approaches to doing this, but each of them has trade-offs when it comes to performance and scalability. In this post I want to explain my scenario, compare them, and choose the best implementation.

Be careful with performance.measure

Be careful with performance.measure

I recently helped a team improve the performance of one of their services. They had already invested some time, but over time the performance was getting even worse! Their Node.js service was suffering from slow response times. At some point, the team added performance tracing using performance.mark() and performance.measure() to understand why the response time was so long. Little did they know that this would make things even worse…

Tools for drawing diagrams in Markdown

Tools for drawing diagrams in Markdown

Markdown is a great format. I use it a lot for documentation. It's much easier to keep documentation up to date by keeping it close to the code. Sure, Markdown has limited formatting features, but it helps to focus on the essential part, the content. But there is one feature missing: Drawing diagrams.

react-beautiful-dnd is ugly

react-beautiful-dnd is ugly

react-beautiful-dnd is a great package for building complex drag and drop behaviors of lists. If you want to reorder the items in a list or move them between lists, this is the go-to package. But the package has a problem: Atlassian has limited its maintenance to security fixes.

I have bad luck with Cypress

I have bad luck with Cypress

Testing is all about being confident that your changes to the software can be deployed to production without problems. While unit or integration tests help you to test details — like the results of a calculation, or whether two parts of your system are working together — you don't know whether all parts of your system are working together as they should. Systems are getting ever more complex and we try to cope with that by splitting it up into parts so that we can handle them or distribute the complexity over multiple teams. Teams develop and deploy small, loosely coupled Microservices that reassemble a bigger system. How do you know that everything works together and that a user can use it? This is where End-to-end (e2e) testing comes into play. And Cypress can be a nice tool for that.

Draw a pattern along a path using SVG

Draw a pattern along a path using SVG

Recently I wanted to create the effect of a cable for an application I'm working on. The cable should have a textile look, similar to a rope, which is quite common right now (for example the charging cable of the current MacBook Pro). I'm using SVG for rendering, so applying a pattern to a stroke path should be easy, right?

prometheus_client, a Prometheus Implementation for Dart

prometheus_client, a Prometheus Implementation for Dart

We recently released the stable 1.0.0 release of our prometheus_client package — a way to expose Prometheus metrics in your Dart application. It's inspired by similar packages like the official client_java for Java or the community package prom_client for Node.js. We have several Microservices written in Dart where we use the package to provide observability. I want to share the experience we had while developing the package.

Choosing dependencies – Snyk Advisor

Choosing dependencies – Snyk Advisor

I recently wrote about my indicators that I use while choosing dependencies in the NPM ecosystem. After writing the post I thought, can you automate these steps to provide a quick view on package health? One tool that does that is the Snyk Advisor. I tried the advisor and want to summarize my experience.

depcheck – Linting dependency usage

depcheck – Linting dependency usage

In my previous post, I wrote about choosing dependencies wisely. The NPM ecosystem is known for its small packages with a lot of dependencies. You can quickly lose track about your dependency usage. Do you have all dependencies configured correctly? Are all of your dependencies still in use? I want to present you depcheck, a small utility to keep track of your dependency usage.