TechLab by Bol

A group of Kotlin enthusiast joined KotlinConf back in December last year in Copenhagen. We invited this group to share their learnings for this conference. Two of the participants are sharing their takeaways from KotlinConf with you.

Our first podcast was about the adoption of Kotlin at bol.com.

What this episode covers

Hope you will also enjoy this episode and our second season.

Guests

• Cas Plattel; Software Engineer in the Fintech domain
• Oscar Spruit; Software Engineer in the Apps domain

Notes

KotlinConf

KotlinConf 2019 on youtube

The subject of this podcast episode is totally in line with the holiday season. Time for the advent calendars in many different formats. One of these formats is the Advent of Code 2019!

The bol.com Tech Community is participating in this event.

What this episode covers

In this episode, we talk with 2 participants and discover what it is all about. We explore what it could do. Our software engineers see it as a good way to sharpen their problem solving and a good exercise for the upcoming bol.com spaces programming championship. Some become really competitive.

Guests

• Erik Tillema; Software Engineer in the logistics domain.
• Carst Tankink; Software engineer, in our webshop. And both the driving force behind the bol.com community participating in this Advent of Code edition.

Notes

The Advent of Code 2019

One of the aspects that keep popping up in software development: Technical Debt. Some created on purpose, for example, to get features into production fast. Some just came into existence...

So, what is Technical Debt? And how to fight it. According to the definition* it can be compared to monetary debt.

What this episode covers

If technical debt is not repaid, it can accumulate 'interest', making it harder to implement changes later on. 

A couple of weeks ago George approached us and said, it might be an interesting topic to discuss because in my team an approach to technical debt is experimented with. So, listen to this episode to find out with our guests.

Guests

• George Katsikopoulos; Young Professional and Software Engineer in the team focusing on Collection Processing, Fraud & Risk.
• Sietse Dols; Product Owner of this team 4E.

Notes

*definition according to Wikipedia.

Boys scout rule

Other thoughts on refactoring code.

By zooming out and thinking we take architecture and design into consideration.

How we tame Google Cloud resources with R2D2. We had some episodes on the cloud already. Now it’s time to discuss how bol.com combines the promises of the cloud and their requirements for Reproducibility and Reliability.

What this episode covers

For instance, balance infinite resources and ultimate autonomy with security.

Within bol.com we developed R2D2. R2D2 stands for our Reproducible Resource Deployment Definition tool which combines the functions of Terraform, Cloud SDK and Puppet Labs.

It helps us to ensure Recovery, Security, Self-service, Stability and Scalability in our move to the cloud.The reason we think we need to secure these aspects: Bol.com has over 100 scrum teams innovating our IT-landscape with over 500 services. We must secure our 10 million customers' data and the data of our 23.000 sellers.

Guests

• Jeroen Schutrup; Site Reliability Engineer in the team that develops the R2D2.
• Quiran Storey; Site Reliability Engineer - just like Jeroen solving operation problems with software solutions.

Notes

Overview of the R2D2 architecture

(Image: https://cdn.sanity.io/images/qxrxmo3r/techlab-prd/cd7a5b48d10ef97931e5f3b4b6e6fcd816114ff3-569x380.jpg)

Google Cloud (GCP)

Google Cloud SDK

The main orchestration tool Puppet

Terraform

Python

Other cloud episodes and blogs:

• Redesign for the Cloud
• Cloud enables data-driven
• Move data in the cloud with Stanley

Shopify's story during SRE 2018 in Dusseldorf

The angle for this episode of our podcast is hackathons. At the time of the recording, there was one going on in our headquarters in Utrecht. What is a hackathon? Why do we organise them? And we talk about some of the initiatives at the current hackathon.

The results of the hackathon were showed during the demotime a week after the hackathon.

What this episode covers

Out of the 20 projects the jury came up with a top 3 and handed over the cup.

Demo Time - Jury handing over the First Price!

(Image: https://cdn.sanity.io/images/qxrxmo3r/techlab-prd/cc56dca8eb2deb92c953014c004e8f2a5bbcdc7a-507x380.jpg)

Guests

• Kardelen Hatun - Software engineer in the Retails Platform Space and organiser of this edition of the hackathon.
• Edith Kanters - One of our robotics enthusiasts. So, guess what her project is about....
• Anastasija Efremovska - Software Engineer for our Tech Platform.
• Andras Herczeg - Software engineer, one of our Young Professionals.

Notes

Some of our hackathon projects make it to PRO.

In this episode, we talk about growing talent. We dive into how we approach this as bol.com in our Young Professional Program. Also called YPs.

What this episode covers

On our recruitment web site, we call this “the IT journey of a lifetime”. Is that just marketing or is there more to it?

Guests

• Bojan Filipovic; software engineer in team Bond, in the content fleet. Just graduated from the young professional program.
• Martin Cekodhima; software engineer in 4B – financial processing – even sexier than Bond. It's FinTech in an e-commerce company, need we say more?
• Remco Snelders; Had several roles in bol.com both in Tech and other parts like Business Development. He is currently the lead for the Young Professional Program.

Notes

Our next Tech Talent Night to explore our IT Young Professional Program – an unforgettable 2-year journey at the largest online retailer of the Netherlands & Belgium.

Online interview with one of our Young Professionals.

Check the IT Young Professional

The state of Reactive Streams - watch the presentation and listen to the podcast. International Keynote speaker Oleh Dokuka gave a presentation on the state of Reactive Streams at bol.com. We took advantage of this opportunity and interviewed him for the podcast.

What this episode covers

The Reactive Streams specification is state of the art for asynchronous, non-blocking data streams with the fine-grained flow control. Clearly, that was done for a good future... but, does it have any future nowadays? How other programming ecosystems reacted to the appearance of the reactive-streams standard and did they adopted that standard?

(Video: https://youtu.be/8iRea_qwOC8)

presentation starts at 6:25.

Guests

Oleh Dokuka is a senior software engineer at Netifi and co-author of the book, “Hands-On Reactive Programming in Spring 5”. He is an active committer to Project Reactor and RSocket, as well as a contributor to Reactive GRPC. In 2019, he was a finalist in the Oracle Groundbreaker Awards in recognition of his expertise with Java.

Notes

• Project Reactor
• RSocket
• The book of Oleh: Hands-On Reactive Programming in Spring 5
• The Reactive Manifesto

This episode is on women in tech. Our guests are two speakers at the upcoming European Women in Tech Conference later this month in Amsterdam. To be honest, if we look at the hosts of this podcast and if we look at our guest list of the past episodes...

What this episode covers

It is still a subject that requires attention.

In an earlier episode we talked about diversity in terms of cultural aspects and in this episode we might find out what the women/men diversity brings into tech. At least that was the idea when we started. It turned into an interesting talk about among other things feedback, personal leadership and vulnerability. So not necessarily the women in tech episode. Interesting for all of of us. Hope you enjoy it.

Guests

• Petra Heesink; Started as a test engineer in development and became an Agile Coach in the Content and Marketing domain in 2018.
• Linda Viksne; Software Engineer in bol.com joined in July. Latvian-born Scotland-bred biomedical scientist turned software developer.

Notes

The mindset intervention - IT professionals taking the lead the talk by Petra and Linda at European Women in Tech.

Imposter Syndrome

In this episode, we talk about User Interfaces (UI) and User Experience(UX). Since this is a very visible topic, everybody has an opinion on it. Even though I’m not working on our webshop I get unsolicited feedback on a regular basis.

Where a lot of the UX Design discussion focuses on our webshop.

What this episode covers

We choose another focus for this episode. The UI that is not common to most of our users but is very much needed for a large part of our 23.000 plaza partners. The Seller DashboarD or SDD in short. The User Interface for other retailers that sell on our platform. This is a substantial part of the turnover that starts here. So, let’s talk about UX Research focused on the platform.

The Seller Dashboard is implemented in the SWAPS that we discussed in an earlier episode of the podcast. We have looked at UX for the webshop before and discussed voice interaction patterns.

Guests

• Koen Olijve; UX designer at bol.com - special focus on the user interface for the plaza partners and the partners that advertise on our website.

Notes

Explanation of NPS

Partner involvement in action: Vote as a partner on the next technical improvements

Task Driven User Interfaces

In this episode, we talk about a way to be inspired and inspiring others, learn from each other and grow your network: Conferences! And more in detail our colleague's road to Devoxx Belgium 2019.

At bol.com we are challenged to present our stories inside and outside bol.com. Inside bol.com we have our great Spaces Summit and meetups, Outside we speak at several conferences. That seems more challenging to a lot of colleagues.

What this episode covers

Especially if it is a conference of 5 days, over 200 speakers and sessions and over 3200 attendees. And our three guests present there. They share their road to Devoxx Belgium.

Guests

• Tom Stoepker, Software Engineer and with his second presence friend of the show. Presenting "Scaling Sustainable Innovation through Team Autonomy”.
• Raul Leal, designer of the backend systems and presenting “Bol.com and the Accelerated Legacy Challenge”.
• Rene Kroon, Software Engineer and with his second presence also a friend of the show. Presenting about “Re-design for the cloud A real-life example of horizontal scaling”. Which might sounds familiar if you listened to previous episodes.

Notes

Re-design for the cloud: a real-life example of horizontal scaling.

Spaces summit, our internal conference

The power of storytelling