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Data on Willem's Blog

Understanding the security concerns in shared hosting

Considering open ports and unused network facing services

Feb. 28, 2019
People pay me to hack them, provided I'll explain how I did it. Read along to learn how hackers use security holes to hack your app, webshop or website!

People pay me to hack them, provided I'll explain how it was done, so future hacks can be prevented. As security consultant, I scan for weaknesses in my clients' apps, webshops and websites. Very often a hack starts by exploiting a security hole that is visible remotely. Read along to learn how hackers find security holes and what you can do to secure them.

My first weeks as dad

On the challenges and rewards of being a father

Jan. 24, 2019
Last Christmas my wife gave birth of our son. It's a life changing experience to become a parent. Read along for my (biometric) findings and some practical tips.

Last Christmas my wife gave birth to our son, a little boy that would change everything! It's an incredible experience to become a parent, especially if it is your first kid. It introduces a whole new way of living, having to deal with regular feeding, caring and sleepless nights. Read along for my (biometric) findings and some practical tips!

Is the Apple Watch the modern tool watch?

Testing the Apple Watch's usefulness in real life

Nov. 2, 2018
I tested the Apple Watch during my work in Frankfurt this week where I had to go inside an internet data centre.

This week I went to Frankfurt for business. I had to perform maintenance to servers in a data centre. This seemed like a great opportunity to test the Apple Watch's usefulness in real life (other than health and fitness). I wondered, is the Apple Watch the modern tool watch?

Rescuing files from a broken harddisk

Make backups to be safe rather than sorry!

Oct. 16, 2018
Yesterday I helped a young woman with her broken computer containing precious photos, could I safe them?

Yesterday a young woman brought me her laptop, it didn't start anymore and it only showed an error message. It turned out to be a broken harddisk. It startled her when I told her that all data on the disk was lost. She told me it contained precious photos of her pregnancy and young child. What could I do?

Swimming and cycling with Apple Watch

Different activities in the workout app in watchOS

Sep. 27, 2018
This month I tested the newest watchOS while swimming and cycling.

This month Apple launched a new Apple Watch series and released an update to watchOS. The focus of the smartwatch is more and more gearing towards health and fitness. This made me curious, how well does Apple Watch work for different activities?

Optimising images for the web and performance

Reduce filesize with jpegoptim, optipng, pngcrush and pngquant

Sep. 26, 2018
Make your website faster by optimising the images. This posts explains how you can do this.

One way to make your website faster is to make it smaller. Not with tiny fonts, but with less bytes! More than half the weight of an average website is because of images. Yet very few people optimise their images for the web and performance, time to find out how much bytes you can safe!

Google Analytics vs AWStats

Understanding web traffic statistics software

Aug. 20, 2018
Comparing Google Analytics with AWStats to find out where they differ and which is better.

This month I have been working on website statistics, tracking traffic using different technologies. Some of my customers use Google Analytics, others use AWStats, and some use both. Which is better is often debated, but few people really understand the differences. Time to shed some light on the magic of web statistics.

Listen to your body

Why I stopped using health and fitness sensors

May 17, 2018
Using health data gathered by sensors and wearables I learned to listen to my body. Now I have stopped using bluetooth sensors all together.

A good customer of mine was once a physiotherapist, he told me about people asking him to "feel their muscles" to tell them how they where doing. "Crazy!" he told me: "I can never feel better than the people themselves, if they only would listen to their body". This caused me to question the health and fitness sensors I use.

Outside the comfort zone: amateur acting

Wearing an heart rate monitor during my debut performance

Apr. 18, 2018
This month I strapped myself with sensors during a little experiment outside my comfort zone: I debuted as amateur actor!

This month I made my debut as amateur actor. I am no Hollywood star, nor do I envy to become one. But I do like crazy experiments and operating outside of my comfort zone often leads to new and refreshing insights. I took part in an amateur drama play and - in the name of science and fun - strapped myself with sensors to measure what happened to my body.

Cyber security: 5 easy tips to protect your server against hackers

Server hardening best practices for Windows and Linux

Mar. 10, 2018
These 5 practical cyber security measures will improve the safety of server, website and data.

This week one of my clients was hacked and asked me for emergency assistance to help secure their server infrastructure. It was a web server that ran WordPress websites on Apache (with PHP/MySQL), including a few webshops with customer data. This hack could easily have been prevented with the following best practices, is your server secure?

Collecting health data with Biostrap

Wearing a clinical-grade photoplethysmography (PPG) sensor for a month

Nov. 15, 2017
Wearing a clinical-grade PPG sensor for a month to collect advanced biometrics from my wrist.

Most wearables (smartwatches, fitness trackers, etc.) use very basic sensors to capture heart rate. Their signal is binary: just counting beats. Biostrap is different, instead of just checking pulses, it captures a high-fidelity PPG waveform. These waveforms are the same kind that doctors use, making me wonder what I could learn from them!

Clouds below my floor

Building a little datacenter in my basement

Aug. 31, 2017
Building a little datacenter in my basement utilising a very fast internet connection.

At my home I have this crazy fast optical internet connection. It is a 600MB up and down fibre connection which directly arrives in my home (no copper cables involved). It's like a private internet highway. Reason enough to find out if I could do something to make better use of all this speedy fiber galore...

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.

Smartwatches vs Mechanical watches

Why I still wear mechanical and why smartwatches have potential

Apr. 30, 2017
Why I still wear a mechanical watch and why smartwatches have potential.

Technology has come a long way since the first computer. Smartwatches today are very much an achievement of miniaturisation of technology. I recently used an Apple Watch Series 2 to find out if technology has come far enough to replace my mechanical watch, today I share you my findings.

One year of cycling

GPS recording an entire year of bike rides using Garmin and Strava

Dec. 31, 2016
GPS recording an entire year of bike rides using Garmin and Strava.

One year ago I started recording all my bike rides, including commutes, short grocery trips and long Gran Fondos. I equipped my bicycles with Garmin Edge computers that recorded location (GPS), speed, cadence and my heart rate. I covered more than 7683 kilometers during 320 hours of riding. It's time to review all the data and share some photos I took along the ride!

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Keep in mind that help is available - I know my way around servers and cyber security
Keep in mind that help is available - I know my way around servers and cyber security
Riding my bike with Apple Watch
Riding my bike with Apple Watch
The box contains three straps, charging cable, charger and two sensors
The box contains three straps, charging cable, charger and two sensors
Suitcase and Maxi Cosi where ready
Suitcase and Maxi Cosi where ready
Using terminal commands to mount a disk under Debian GNU/Linux
Using terminal commands to mount a disk under Debian GNU/Linux
Wahoo TICKR, waist worn strap, measuring heart rate in realtime
Wahoo TICKR, waist worn strap, measuring heart rate in realtime
This photo was taken during a ride through the forest near Hilversum. The nearby trees really give you a sense of speed (and reason to stay focussed on steering straight...)
This photo was taken during a ride through the forest near Hilversum. The nearby trees really give you a sense of speed (and reason to stay focussed on steering straight...)
The broken laptop containing precious photos
The broken laptop containing precious photos
For sure I will need some time to get used to not wearing sensors... note the white stripe on my wrist :-)
For sure I will need some time to get used to not wearing sensors... note the white stripe on my wrist :-)
Once a hacker knows what software your website uses, its easy to lookup known security holes using databases like cvedetails.com
Once a hacker knows what software your website uses, its easy to lookup known security holes using databases like cvedetails.com
... now you don't - Biostrap wears well and easily goes under your sleeve
... now you don't - Biostrap wears well and easily goes under your sleeve
Playing drama is a team effort - and the on stage interaction is what makes it fun!
Playing drama is a team effort - and the on stage interaction is what makes it fun!
Heart rates during the two performance nights, left my debut, right the second performance
Heart rates during the two performance nights, left my debut, right the second performance
Biometric readings covering the month leading up to the performance
Biometric readings covering the month leading up to the performance
Heart rate during my debut - with annotations explaining what happened
Heart rate during my debut - with annotations explaining what happened
Digital technology and social change (by Martin Hilbert, University of California)
Digital technology and social change (by Martin Hilbert, University of California)
In the Netherlands there is no shortage of dykes. Many of them have long straight bike lines on them. This one is near
In the Netherlands there is no shortage of dykes. Many of them have long straight bike lines on them. This one is near "Hoek van Holland", you can see the Rotterdam Maasvlakte industry at the horizon.
Using nmap to scan a hosting server, identifying network facing services and open ports
Using nmap to scan a hosting server, identifying network facing services and open ports

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