It’s common sense of course to keep your codebase clean all the time, but this isn’t always the case. It simply happens that a codebase grows in ways that were not foreseen on forehand resulting in an unclear architecture or dirty code (that must be the opposite of clean code). In this article I’d like to share our experience in dealing with such a situation, why we needed to refactor, what we did and how it improved our codebase. Why you need to refactor Modern software engineering is an agile…Read more
On June 13th, we organize the third edition of Spaces Summit: an internal tech conference for and by bol.com IT. From the start of the idea three years ago at a “borrel” (Friday afternoon drinks), Spaces Summit has become the biggest event inside bol.com IT to get inspired, learn, share knowledge, show off and get together as a community . This third edition will again be bigger than last year: a total of 500 attendees (150 more than last year!), an unusual afternoon keynote, inspiring talks on a variety of subjects, good…Read more
On Wednesday the 26th of June bol.com will host a meetup about Angular and Progressive Web Apps (PWA). Lars Meijdam en Marcel Visser (both Team Rockstars IT) will present on Progressive Web Apps. What are these PWA’s? What sets them apart from native apps? How to create them? Stefan Nieuwhuis will dive into taming huge enterprise applications with Mono repos, Design Systems & Web Components. Program 17.30 -18.30 Welcome, food and drinks 18.30 – 19.15 Progressive Web Apps – Lars Meijdam en Marcel Visser – Rockstars IT 19.15 – 19.45…Read more
On Wednesday the 15th of May bol.com will host a meetup about migrating from on-prem to the Google Cloud Platform (GCP). After dinner is served, René Feiner, director of engineering at MessageBird will kick off the evening and talk about how and why they moved from their datacenter to GCP. Then, after a short break, Maarten Dirkse, cloud advocate at bol.com, will discuss bol.com’s ongoing migration to GCP and what lessons they have learned along the way. So if you’re interested in why companies migrate to the cloud and how…Read more
TL;DR: We share our experience on how we built a conversational bot with Finite State Machines. It turned out to have its own shortcomings so we built a DSL to design our flows and called it “Sushi”.
Sushi is a more flexible and straight-forward tool to build complicated flows.
At bol.com we use GraphQL in our IT landscape, and we’ve found a convenient way of working with these API’s we would like to share. By generating our GraphQL queries from Java objects by using annotations, developers don’t need to worry about the query, and don’t need to maintain both a query and a domain object anymore.Read more
TL;DR: this article discusses in detail my presentation at Spaces Summit 2018. I talked about the need to stop smashing our keyboards and “blindly” focus on “high-speed”, and start thinking about what we are doing, why and how we are doing it.Read more
In many systems at bol.com the response speed of our systems is very important. This blog is about the data structures and algorithms we used to make a specific analysis step a lot faster: Finding the longest matching string prefix.Read more
The biggest e-commerce company in the Netherlands and Belgium, bol.com, set out on a 4 year journey to rethink and rebuild their entire ETL (Extract, Transform, Load) pipeline, that has been cooking up the data used by its search engine since the dawn of time.Read more
Last June, Spaces Summit was organized by and for bol.com employees. At Techlab, we want to celebrate this event by highlighting two presentations every month. This month, let’s get meta, and talk about organizing a conference. After that, we’ll go full geek again and look at Kotlin, to cure the Java headache you probably didn’t realize you were having in the first place.Read more