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Payments on Willem's Blog

Designing a multi dimensional capacity queue

Managing kitchen-, delivery- and pickup capacity

Dec. 2, 2020
Dealing with a capacity queue is challenging, but if you take the time to model it right it is possible to create a performant and reliable system.

This month I needed to create additional dimensions to a capacity queue mechanism. The food ordering app that I created needed to be able to restrict capacity based on the number of orders, the contents in individual orders and the dispatch type (takeaway/delivery). Read along to find out how I used a Lambda Architecture to do this.

Designing and implementing a (micro) payment system

Monetising my blog with coffee, Apple Pay and Mollie

Mar. 25, 2020
Designing and implementing a micro payment system with an emphasis on simplicity. Read about how I did it in this post.

Online payments are now more important than ever as businesses are disrupted by the COVID-19 virus. It drives my customers to seek new ways to make money online. I designed and implemented a (micro)payment system. This post is about achieving simplicity by solving complex challenges.

The day I killed my LAN

Turned off my local network and went 4G only

July 31, 2017
I killed my office LAN and went 4G only. Saves a lot of clutter, energy and money.

Today I called my provider to quit my office's ADSL internet subscription, I don't need it anymore. I have turned off my local area network and switched my workflow onto mobile internet only. The simplicity and savings actually surprised me so much, that I made blog post for it.

Cash is king, or is it?

The wallet- and cash-less experiment

July 15, 2016
Is the time right to ditch the wallet?

Very often I see men carry a wallet filled with plastic: multiple debit and credit cards plus a bunch of loyalty programs and membership cards. Then, some even top it off with stinky paper money and sticky metal coins! It made me wonder if I can free up one pocket by ditching the wallet?

All blog posts
Calling Mollie from NodeJS using promise based JavaScript
Calling Mollie from NodeJS using promise based JavaScript
The iPhone with case is only slightly thicker.
The iPhone with case is only slightly thicker.
iPad Pro + Apple Pencil replacing paper
iPad Pro + Apple Pencil replacing paper
Maybe... my next office? ;-)
Maybe... my next office? ;-)
Handling payment status updates
Handling payment status updates
Eating pizza during development is how you
Eating pizza during development is how you "live the algorithm"
Stacking two plastic cards is easy
Stacking two plastic cards is easy
Sketched sequence diagram of payment process
Sketched sequence diagram of payment process
An event stream of orders is the heart of the mechanism, queries are fulfilled by looking at this stream: how many pizza's will be ready at 18:00hrs?
An event stream of orders is the heart of the mechanism, queries are fulfilled by looking at this stream: how many pizza's will be ready at 18:00hrs?
The iPhone case is large enough to hide cards.
The iPhone case is large enough to hide cards.
Mollie is a payment provider that supports many different payment methods, including credit cards, PayPal, iDEAL, Sofort, Giropay, SEPA, various bank apps and Apple Pay
Mollie is a payment provider that supports many different payment methods, including credit cards, PayPal, iDEAL, Sofort, Giropay, SEPA, various bank apps and Apple Pay
Designing the coffee cup using Picta Graphic for iPad
Designing the coffee cup using Picta Graphic for iPad
Music from the office cabinet - iPhone as a connected music player. Quite the solid rock show in combination with Apple Watch as remote.
Music from the office cabinet - iPhone as a connected music player. Quite the solid rock show in combination with Apple Watch as remote.
Translating the design sketch (left) into a prototype (right) on iPad
Translating the design sketch (left) into a prototype (right) on iPad
Time to drink coffee
Time to drink coffee
Three capacity constraints: kitchen / delivery / pickup
Three capacity constraints: kitchen / delivery / pickup
Interface concept sketches, exploring different options to leave a message and buying multiple cups of coffee
Interface concept sketches, exploring different options to leave a message and buying multiple cups of coffee
Developing the user interface using Blink and Inspect Browser on iPad
Developing the user interface using Blink and Inspect Browser on iPad

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