In my free time I can be found cycling, having a few glasses of wine with
friends or just having fun. My other free time activities include reading
books, skiing, playing chess and go and exploring all kind of topics I
get interested in. I also have 2 cats: Ruby and Perl.
Consultancy
I work as a consultant for Sue. In this role I help customers design,
implement, improve and automate the rollout and management of their IT
infrastructure in the cloud and/or on premise.
Training
Beside my consultancy activities I am also active as a technical trainer,
with a focus on teaching SaltStack and SUSE courses.
Feel free to invite me for dinner if you think we can have an interesting or
mutual benefitting conversation. If you have another offer, opportunity, or
introduction that might make my life more interesting you can send an email
to contact (at) jeroen (dot) se. Due to my other priorities, for example
playing with my cats, I’ll only respond to those proposals that are a good
match for my schedule and interests. Please do not try to call me by phone if I
do not know you yet and you somehow managed to find my phone number somewhere.
Technical Computer Science
MSc.
I have a masters degree in technical computer science from the University of
Twente with a specialisation in security. My master thesis focussed on the
analysis of Spam filters. During my study I also followed a crypto analysis
course.
My Certifications
An overview of when I got which certificate
2019-06
-
SUSE Certified Engineer in Enterprise Linux 15
2019-06
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SUSE Certified Administrator in Enterprise Linux 15
2018-12
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SUSE Certified Instructor
2018-12
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SUSE Enterprise Architect
2018-11
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SUSE Certified Engineer in Enterprise Linux 12
2018-11
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SUSE Certified Administrator in Enterprise Linux 12
2018-09
-
AWS Certified Solutions Architect - Associate
2018-09
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AWS Certified SysOps Administrator - Associate
2018-07
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SUSE Certified Engineer in OpenStack Cloud
2018-06
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SUSE Certified Administrator in Systems Management
2018-06
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SUSE Certified Administrator in Enterprise Storage 5
2018-04
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CompTIA Certified Technical Trainer
2018-01
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SaltStack Certified Trainer
2017-11
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SaltStack Certified Engineer
2017-10
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SUSE Certified Administrator in OpenStack Cloud
2017-08
-
Red Hat Certified Architect
2017-08
-
Red Hat Certified Specialist in Containerizing Software Application Development
2017-08
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Red Hat Certified Engineer In Red Hat OpenStack
2017-05
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Red Hat Certified System Administrator In Red Hat OpenStack
2016-10
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Red Hat Certified Specialist in Ansible Automation
2016-02
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Red Hat Certified Engineer (RHEL 7)
2016-02
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Red Hat Certified System Administrator (RHEL 7)
2015-12
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IPMA-D
2015-07
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TOGAF 9 Foundation
2014-11
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Mirantis Certified Administrator for OpenStack
2014-03
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Puppet Professional
2013-08
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Red Hat Certified Specialist in Cluster and Storage Management
A short overview of how I manage my agenda and todo's.
The Basics
I work with a GTD (Getting Things Done) system fine tuned to my needs
for over a decade. Googling for GTD will give you enough references to get to
understand the concepts of GTD. The most important concepts are probably you
have to capture everything (more or less) and if actions take less than 2
minutes do it immediately. Finally there is also a concept called the weekly
review, which basically states, every week at a set time review all your
appointments, commitments, todos etc. to determine next actions.
Capturing everything
I capture every task/reminder/appointment/meeting etc. that comes in.
Appointments/meetings go on the calendar. Tasks/reminders go in to my todo
list. If a task has a deadline the deadline is added to the task.
Then there are the waiting fors, basically that are tasks delegated to someone
else. They also go into my todo list (marked as waiting for) and get a deadline
for the date I need to get a status update or it should be finished.
Some details
The two minute rule
My real application of the two minute rule is something like this: Takes it
more than 2 minutes? If so, put it on my todo list. If not, do I want to do it
now or is it too annoying to do now? In the latter, put it on the todo list. If
the former, do it now.
Email
Email is quite simple. If I need to reply now, I reply. If I have to put time
in it I flag it as todo and put it on the todo list and archive the email. If
it is an email I have send and I am waiting for a reply/action, flag it as waiting
for, put it on the waiting for list in the todo application and archive the
email.
Meetings/appointments
Meetings and appointments just go onto my calendar, nothing fancy there. Weekly
I have 5 hours marked as unscheduled. These blocks can move freely within a
week, but not be moved outside the week boundaries. This makes sure I have slack
time in my agenda.
Tasks and EDL
Tasks that have to happen sometime, are put on my todo list. Tasks that have a
deadline are scheduled at the last possible moment in my agenda, via the
calendar integration of my todo application. One very important factor here is
that on average I overestimate the duration of all my tasks. Except from the
overestimating this is basically similar to the Earliest Deadline Late
scheduling algorithm.
Why overestimate how long things take?
To quote Nassim Nicholas Taleb: "When fragile, [..]: maintain a distance from
ruin, that is, from hitting a point in the periphery should it be dangerous.
This schema explains why if you want to minimise the probability of the plane
crashing, you may make mistakes with impunity provided you lower your
dispersion."
So basically I try to avoid becoming unschedulable at all cost. Hence the
overestimating and the hours marked as unscheduled.
When to do EDL planned tasks?
The most important thing when using EDL scheduling in your calendar is
basically that in case of idle (free) time you do the first upcoming planned
EDL task that can be executed. Or to put it another way, everything is planned
at the last possible moment, but most likely done before the scheduled time.
