TechLab by Bol

Warehouse mechanization is a part of our IT landscape where our IT meets the physical world. It is one of those places where we encounter that while we could scale our IT almost indefinitely in the cloud, the physical world and warehouses don't work that way. As you listen to this episode you will learn how the world of IT has to adapt to the physical world to make things work.

And as Peter states this is also the place where e-commerce comes to life.

What this episode covers

This is the place where all the bits and bytes in the webshop have to lead to tangible products that are picked and delivered to our customers. By all measures a real interesting place.

:

• What sets warehouse mechanization apart from other software engineering?
• To enable our growth we need more and more warehouses. What do we need to get a warehouse live from a WMS and/or warehouse mechanization perspective?
• To what extent do you need access to the physical parts?
• Do we use simulation?

Guests

• Frank Lakerveld – WMS consultant in Logistics
• Dennis van Duijn - Systems Engineer in Logistics

Notes

• Simulation and Data Science for our warehouses
• Performance boost the picking algorithm
• The life of a WMS consultant

Some aspects of software engineering are easily overlooked. In the book The Programmer's Brain some of these like reading code, thinking about code and collaborating on code are at the centre. In this episode, we talk to the author of this book to guide us through these aspects.

To improve your coding skills it is good to know how your brain works.

What this episode covers

That will enable you to set your brain to work for you. If you spent significantly more time on reading code than on writing code, shouldn't we focus more on learning to read code? These are the topics we explore in this episode.

If you’ve ever wondered what working smarter instead of harder is supposed to look like, you should read this book. I am already seeing improvements in my day-to-day work.What the programmer's brain covers

• What every programmer needs to know on how the brain works.
• What you should know about cognition.
• A lot of exercises for programmers.
• How do I improve myself on coding?
• What is the difference between an expert and an intermediate programmer?
• And Felienne shares ideas and working formats to improve collaboration on programming.

Guests

• Felienne Hermans - Associate Professor at LIACS - Universiteit Leiden. Keynote speaker, podcast host and book author.

Notes

• The book on bol.com: https://www.bol.com/nl/nl/p/the-programmer-s-brain/9300000033887759
• Code Reading Clubs: https://code-reading.org/
• More on Engineering Productivity.

Imagine you want to buy something. You go to bol.com and you start typing the article in the search bar. Automatically you will be served suggestions and as a result, you want a limited number of articles from our 30 million products catalogue.

What this episode covers

You select the product you want, press the buy button and there it is, at your doorstep at the selected moment.

Sounds simple, right?

Inspired by a talk of our guest of this episode earlier this year, we wanted to find out what's behind the search bar. We wanted to understand search queries. Simple at first glance, but when we dive into it we found out it's way more complex than you might think.

We had great learning: as a customer, I help other customers to improve their search results. How that works? Listen to this episode.

(Image: https://cdn.sanity.io/images/qxrxmo3r/techlab-prd/bd51783981f1b35051359902ea03bea2213d1a9f-680x361.jpg)

The search bar on the bol.com website

What it takes to search

Questions will be answered like:

• How do I search for a product?
• We are not talking about the Google Search Engine and SEO and why we do not use Google Search?
• How important is search?
• What happens when you type in a search query?
• Terms you need to understand when we talk about search: relevancy, ranking/sorting, first page, tail page.
• What items do you need to take into account: Spelling, Target Category, Filter values, Broadness.
• How do we take trending topics into account?
• As an International Engineer, is it hard to work on a search engine with Dutch Product Content?

Guests

• Nikolai Bogdanov – Software Engineer in the Buying domain – Help me find.

Notes

• Spaces summit Talk on Youtube
• The search result of the red water kettle as given in the example
• Search via Voice is different, check this episode for more detail

In early April the latest version of our Retailer API was launched. Given the importance of the API for almost 15.000 partners this was again a major step. Over the years the retailer API became the heart and soul of our ecosystem.

What this episode covers

But this path wasn't always that obvious. It took vision, decisiveness and perseverance to get this far. In this episode, we explore this journey.

The importance of the Retailer API

API’s are considered a major part of a serious platform. They enable growth and stability. The 80/20 rule applies when it comes to the usage of the partners of their interaction with bol.com. 80 per cent of the sellers use the seller dashboard, 20 per cent the Retailer API. But when it comes to the number of orders, it’s the other way around. 80 per cent via the API and 20 per cent via the dashboard. And if you imagine that over 50% of the goods being bought at bol.com are goods from our partners, it shows the importance of this API.

What we discussed about the Retailer API (Application Programming Interface)

• What is an API in simple terms?
• Why is API used?
• How did we start the API?
• What functionality is in the API?
• What is API and types of API?
• What is API to API integration?
• What is API example?
• How does the API interact in the Landscape?
• How do we balance "adding new functionality" vs. "maintenance"
• Why became the Retailer API the heart and soul of the ecosystem?

Guests

• Maarten Roosendaal – Business Architect / Product Owner for our Retailer API;
• Jarno Walgemoed - Owner at Sourcelabs; Software engineer with a strong focus on partner API’s at bol.com and host of the sourcelabs podcast

Notes

• In an earlier episode, we talked about API development for bol.com and we also touched upon the Open API. The API is used for customer interactions. https://techlab.bol.com/api-development-for-the-retail-platform/
• API Developers can find more information here: https://developers.bol.com/

Engineering Productivity

With the growth of our engineering community, the need for more focus on engineering productivity is clear. We invited two experts to discuss this topic with us. We actually got to this point when one of our listeners pointed out one of the products we are using for this and how awesome a topic that would be for our podcast.

Backstage

The product he was referring to, is Backstage.

What this episode covers

Backstage is a platform for developer portals that is used as an app store for tools for software engineers. This product was build inside Spotify and later on open-sourced by them.

We thought it was a good idea to get these tools in a unified packageQuestions we touch upon

• What does engineering productivity mean?
• How is engineering productivity measured?
• Why is engineering productivity important?
• How can engineering productivity be improved?
• What is Backstage open source?
• Who uses backstage io?
• Why Backstage io?
• What is Spotify backstage?

Guests

• Roy Jacobs – Software Engineer – Technical Platform. Already joined us when we explored Axle – the opinionated support for our scrum teams using Java
• Onno Ceelen – Product Manager – Technical Platform

Notes

• Backstage homepage
• Introduction to Backstage at Spotify
• Axle the bol.com Springboot framework: podcast, blog on Axle usage

How interaction resulted in a guest appearance

“We like interactions and feedback”, that’s what we say in our outro. The guest of our show reacted to one of our podcasts earlier this year. We reached out to him and invited him to the podcast.

What this episode covers

Why? Because it’s good to look in the mirror. Check our stories with the outside in view. And that’s exactly what we are going to do in this show. Getting the outside perspective on the edges of autonomy.

Discussed Items on the edges of autonomy

• Why do you interact and why is interaction helpful?
• How can we complete our stories?
• What items do you miss when you listen to the stories in a holistic way?
• What is an example of autonomy?
• What is team autonomy?
• What is autonomy and why is it important?
• Does autonomy mean control?
• What are the three types of autonomy?
• Is autonomy good or bad?

Guests

• Thomas Heijtink - Full Stack Software Engineer & Product Owner at Fleetgo, but above all loyal supporter of the show and searching the interaction.

Notes

• Agile at scale
• Man on the moon

How Data Science supports us to predict the unpredictable

Just like for any store, forecasting is an important tool to support the business and its profitability. At bol.com we have worked on several major iterations of our forecast. One of the hosts worked on a large leap in forecast performance over 8 years ago. You can check some another leap we have made while listening to our podcast episode from May 2019 - nom more crystal ball for forecasting, Data Science it is.

In this episode, we explore how we have improved on that one.

What this episode covers

One of the leaps we made Is in the operational part of running a Data Science-based forecast in production. This is intriguing because this mechanism at the same time speeds up our innovation speeds because it enables us to do more experiments and train our models more often.

One important input we added to our forecast during the pandemic was the "Covid Severity Index". This improved our forecast performance and enabled us to work with scenarios. The latter also supports all the other retailers that sell on our platform.

Discussed Items on forecasting with Data Science in Covid-19 Times

• Forecasting in general
• Specific forecasts for specific needs
• Aggregation
• Coherence
• Who is responsible for what?
• What can we predict with Data Science?
• How do you forecast sales Data Science?
• Tech used
• Input data
• Experiment by using branches to innovate faster
• Airflow
• Dr. Watson as a gatekeeping tool to validate the output
• Corona impact on forecasting
• Covid Severity

Guests

• Catia Silva – Data Scientist in forecasting. Presenting at conferences
• Eryk Lewinson – Data Scientist in Forecasting

Notes

Why build an open-source FTP server in Rust?

Sometimes, I must admit I’m a little dazzled by all the languages, frameworks and stuff our engineers work with. So, when our guest of today explained to me some of the intriguing aspects of the language we will be discussing in this episode I had to stretch my mind a little. I managed and could follow his explanation.

What this episode covers

And I found a great topic for this podcast.

In the episode, we explore the Rust programming language and our first open-source code in this language: unFTP. When you need to FTP but you don't want to. We will show you the advantages of using this FTP server in the Cloud for the cases that still require you to FTP.

What we discussed

• The programming language Rust
  • What is Rust and why is it so popular?
  • What programs are written in Rust?
  • Why should software engineers learn Rust?
• The project unFTP
  • Why unFTP?
  • Where does the need for a cloud FTP server stem from?
• unFTP as Open Source project
  • We open sourced unFTP. What are we trying to achieve by doing this?
  • What are the results so far?
  • Did it help that unFTP featured on This week in Rust?

Guests

• Hannes de Jager – Software engineer for the retailer bol.com
• Rob Klein Gunnewiek - we called him System Engineer Extraordinaire last time he was on the show. Besides that, he is one of our Site Reliability guru's.

Notes

• Turning rusty tech into Rust ~ When you need to FTP but don’t want to
• unFTP Github'
• libunftp on crates.io
• This week in Rust on unFTP
• The Terraform wrapper that was mentioned

Who is the Podcast

.



Guests

?

This will be a bonus episode. Maybe not that tech-related but instead you will listen to a very energetic, passionate and inspiring person: The Podcast

Notes

What is the key competence of our business analysts (BA)

We talked about domain knowledge, tech affinity and building bridges between stakeholders and software engineers. Sometimes the business analyst is almost seen as a project manager. Aligning with product owners is key in this role.

What this episode covers

Every business analysts within bol.com fills in this role differently but about one thing they are very clear; for our business analysts curiosity is key.

Time to dive into this BA role. We see this role as a key to success in our multidisciplinary product teams. They form a bridge between the stakeholders with their business requirements and the software engineers providing the tech solutions.

Guests

• Adinda Biesbroeck – BA Retailer portal – 5 years at bol.com.
• Naomi Platenburg – BA Capacity Management Warehousing – Daily steering – started in March after an internship.
• Mitch de Vries – BA Team 15 C – Contract en Condition management in Retailer1 - 3 years at bol.com.

Notes