In this session, we show you how we use “web scale” patterns to achieve scalability and flexibility in our back office software. We will guide you through how we apply patterns like CQRS, event sourcing, polyglot persistence and micro services to solve puzzles in our back office services. Interesting is that in our experience we don’t need these just to solve a technical problem. It helps us to solve some of our business problems!

1. Applying “web scale” patterns
Peter Paul van de Beek
AMSTERDAM 16 - 17 MAY 2017

2. The shop for everyone
2

3. Bol.com from online bookshop to portal for specialised online channels
serving the entire Dutch-language region
3
Books Entertainment Electronics Toys
Preloved sales eReading
Small Appliances
White Goods
Marketing via bol.com
Baby
Cooking & Tableware
Health & Beauty Home & BedroomPets
Garden & DIY
2004-2007 2010
Sports & Leisure
1999-2003 2010 2011 2012 2013 2014 2015
Jewellery & Watches
Bags & Accessories
SECOND-HAND
ePRODUCTS
COMMERCIAL
MARKETING
NEW SPECIALISED CHANNELS
ALSO WORTH KNOWING
Startup in a portacabin Active in Belgium Takeover by Ahold
2008-2009

4. • Over 7,4 million active customers
• Virtual footprint of almost 2 million
per day
• Nearly 15 million products
• More than a 1.200 employees in
Utrecht
• 1 in 2 Dutch and Belgian consumers
who shop online, do so on bol.com
• Ranked among top 10 businesses for
customer satisfaction
4
Where is bol.com now?
>95% >75%
Brand awareness

5. 5

6. Our promises to our customers
CQRS
Event Sourcing
Polyglot persistence
Micro services

7. As a proposition manager
I need real time stock levels in the web shop
So we can offer al kind of last mile services

8. Inventory Management
8
CQRS
command query
Received Goods
Stock Corrections
Sales
Shipments
Stock
Levels

9. As a buyer
I need to calculate the value of allowances
So I can offer lower prices to our customers

10. 10
Event Sourcing
Event store
Event store
Invoiced
purchases
Consumer
sales
Condition
Calculation
Invoices&Accruals

11. As a logistics planner
I need to handle different types of warehouse orders
So I can handle a variety of services

12. As a retail platform billing manager
I need to store and trace different kinds of transactions
So I can invoice retailers

13. Polyglot persistence - Schema and schema less data
13
Relational DB
Document DB
Key-Value Store
Column-family DB

14. As a CIO
I need scalable and reliable software
So I can run a great web shop and innovate at speed

15. (micro) services
15
• Smaller functional responsibility.
Or just smaller services;
• Independent deployment. Each
service has continuous
integration (CI) and continuous
deployment (CD);
• Mayfly

16. Thanks!
till next bol.com