Don’t use Slack Incoming WebHooks; App Creation is Dead Simple!

At Wehkamp we ❤️ Slack! Seriously, in order to improve our efficiency, we’ve connected many of our applications, alerts and dashboards to Slack channels. But, as with all things, there is a right way and a wrong way of integrating a webhook at enterprise level.

Let’s explore how easy it is to create an application.

Full Stack Live Meetup: How to handle the immense web traffic caused by a successful influencer campaign? (Dutch)

Chris Vahl (Cloud Engineer) and me did a talk on Full Stack Live #2 (Orange Talent: At Wehkamp we did a very successful influencer campaign, but it didn’t go well for our website. In this session we discuss what happened and how we mitigated our problems. We also show how we want to move forward using Kubernetes, Karpenter and Keda, to create a platform that scales better. This session is in Dutch.

Jupyter Notebooks + VSCode Dev Container with Puppeteer support

Let’s run Jupyter notebooks in a Visual Studio Code development container, so we keep our host system clean and our development setup replicable. We’re building a scraper, so let’s add support for Puppeteer (pyppeteer) as well!

DateOnly in your .NET 6 API

Let’s face it: sometimes DateTime is just too much: you only want to deal with dates. Since .NET 6, we finally have support for DateOnly. In this blog I’ll look at how to interact with it and how to add it to your Swagger API docs.

Task: take some website screenshots and put them in a folder (in parallel)

You have a bunch of online services that let you take screenshots of a site and save them in a folder. While it can be very useful to pay for such a system, it is not so hard to create it. Let’s use Chrome / Chromium with Puppeteer and Node.js (cluster) to take some snapshots in no-time. We’ll use the Puppeteer Cluster package to run multiple threads / workers to grab those screens in parallel. We’ll be using TypeScript.

Retry with Exponential Back-Off utility method

The web is unreliable. Here’s a compact exponential back-off retry utility for TypeScript — one function, no dependencies, proportional jitter included.

Using the S3P API to copy 1.3M of 5M of AWS S3 keys

This week we had to exfil some data out of a bucket with 5M+ of keys. After doing some calculations and testing with a Bash script that used AWS cli, we decided to go a more performant route and use s3p. They claim to be 5-50 times faster than AWS cli 😊.

Named Arguments in a Bash Script

Positional arguments like $1 and $2 are hard to read. This Bash pattern maps named options to explicitly allowed variables and validates the required input.

Parsing JSON data from S3 (Kinesis) with Spark

Yesterday we’ve encountered a curious problem: we needed use Spark to parse JSON data that was produced by AWS Kinesis. Unfortunately, the data was in a concatenated JSON format. Spark does not support that format, so we had to come up with something our selves.

Having fun grouping arrays into maps with TypeScript

I love the group by SQL command, and sometimes I really miss these SQL-like functions in languages like JavaScript. In this article I explore how to group arrays into maps and how we can transform those maps into structures that work for us. We will leverage TypeScript generics to do transformation on data structures in such a way that the end-result remains strongly typed: this will make your code more maintainable.