Freelance DevOps / Linux engineer

0 1
0 name ing. Sander Lentink
1 currentcity Lelystad
2 birth year 1991
3 languages EN, NL
4 drivers license A, B
5 phone +31617012655
6 email sv@lent.ink
7 links
  • www.lentink.consulting
  • linkedin.com/in/svlentink
  • github.com/svlentink
  • blog.lent.ink

About

Eager to create and learn, diligent and always looking to get the job done. Technologies are solely a means to get the job done. Security minded and willing to discreetly address issues.

Ambition

Love to gain more experience with container orchestration such as kubernetes. Like it when my work incorporates data science, security and writing code.

Education

0 1 2 3 4
0 MSc. Security and Network engineering University of Amsterdam 2017-2019 in progress
1 BSc. Software engineering Windesheim 2012-2016 graduated
2 Propedeuse Computer engineering Windesheim 2011-2012 graduated
3 community college Mechatronics Landstede 2007-2011 graduated

Certificates and courses

0 1 2 3 4
0 minor Artificial Intelligence University of Amsterdam 2014
1 minor Mathematics Utrecht University 2014
2 minor Web technology Windesheim 2013
3 Certificate 7 habits of highly effective people FranklinCovey November 2012
4 Certificate Introduction Android Development InfoSupport December 2011
5 Certificate Basic Safety VCA Cito February 2007

Knowledge fields


knowledge tree                                                              
 +-- Configuration Management CM                                            
 |   +-- CI/CD integration, deployment                                      
 |   |   +-- gitlab                        August 2018    -> November 2018  
 |   |   +-- travis                        February 2017  -> October 2018   
 |   +-- Infrastructure as Code IaC                                         
 |   |   +-- ansible                       March 2017     -> April 2017     
 |   |   +-- terraform                     November 2018  -> November 2018  
 |   +-- Version Control Systems VCS                                        
 |       +-- Git                           2013           -> 2019           
 |       |   +-- Gitlab                                                     
 |       |   +-- Github                                                     
 |       |   +-- Bitbucket                                                  
 |       +-- svn                           2012           -> 2013           
 +-- containers                                                             
 |   +-- container orchestration                                            
 |   |   +-- DC/OS Mesosphere              February 2017  -> November 2018  
 |   |   +-- kubernetes k8s                June 2018      -> 2019           
 |   |   +-- microservices                 June 2016      -> 2019           
 |   +-- docker                            February 2015  -> 2019           
 |   +-- lxc                               March 2017     -> 2019           
 |   |   +-- lxd                           November 2017  -> 2019           
 |   +-- rkt                               November 2017  -> December 2017  
 +-- data                                                                   
 |   +-- cache                                                              
 |   |   +-- Memcache                      April 2017     -> October 2018   
 |   |   +-- Redis                         June 2016      -> October 2018   
 |   +-- data science                                                       
 |   |   +-- D3js                          2015           -> April 2018     
 |   |   +-- Python                                                         
 |   |   |   +-- Numpy                     September 2018 -> October 2018   
 |   |   |   +-- Pandas                    September 2018 -> November 2018  
 |   |   +-- web scraping                                                   
 |   +-- database                                                           
 |   |   +-- MySQL / MariaDB               October 2011   -> 2019           
 |   |   +-- NoSQL                                                          
 |   |   |   +-- MongoDB                   July 2016      -> October 2018   
 |   |   |   +-- OrientDB                  March 2015     -> June 2015      
 |   |   +-- PostgreSQL                                                     
 |   |   +-- SQL server                    2012           -> 2013           
 |   +-- formats                                                            
 |       +-- AMQP / RabbitMQ               February 2017  -> 2019           
 |       +-- JSON                                                           
 |       +-- XML                                                            
 |       +-- YAML                                                           
 +-- infrastructure                                                         
 |   +-- Linux                                                              
 |   |   +-- Alpine                        2016           -> 2019           
 |   |   +-- Ubuntu / Debian               2012           -> 2019           
 |   +-- Openstack                         January 2017   -> February 2017  
 |   +-- VM                                                                 
 |   |   +-- KVM                           February 2017  -> October 2018   
 |   |   +-- Xen                           November 2017  -> 2019           
 |   +-- cloud                                                              
 |   |   +-- AWS Amazon Web Services       February 2017  -> November 2018  
 |   |   +-- DNS                           2016           -> 2019           
 |   |   |   +-- bind                      September 2018 -> October 2018   
 |   |   +-- Load balancing                July 2017      -> September 2018 
 |   |   |   +-- HA-proxy                  March 2016     -> October 2018   
 |   |   +-- Reverse / TLS proxy                                            
 |   |       +-- Apache                    January 2017   -> September 2018 
 |   |       +-- Nginx                     2015           -> 2019           
 |   +-- monitoring and notify                                              
 |       +-- Slack API                     2017           -> 2018           
 |       +-- elastic search                April 2017     -> July 2018      
 |       |   +-- kibana                                                     
 |       |   +-- logstash / grok           November 2017  -> December 2017  
 |       +-- email                                                          
 |       |   +-- exim                      April 2017     -> 2019           
 |       |   +-- smarthost                                                  
 |       +-- nagios                        December 2016  -> November 2018  
 +-- languages                                                              
 |   +-- Bash                              February 2015  -> 2019           
 |   +-- HTML5 / CSS3                      September 2011 -> 2019           
 |   +-- Java                              April 2012     -> January 2014   
 |   +-- Javascript / Node.js              February 2015  -> 2019           
 |   +-- LaTeX                             2014           -> 2019           
 |   +-- PHP                               September 2011 -> June 2012      
 |   +-- Python                            February 2017  -> 2019           
 |   +-- R                                 November 2017  -> March 2018     
 |   +-- Ruby                              February 2016  -> May 2016       
 |   +-- SQL                               September 2011 -> 2019           
 |   +-- c#                                January 2013   -> June 2013      
 +-- process management                                                     
 |   +-- SDLC                                                               
 |   |   +-- Agile                                                          
 |   |   |   +-- Kanban                    2013           -> 2019           
 |   |   |   +-- SCRUM                     April 2013     -> 2019           
 |   |   |   +-- User stories                                               
 |   |   +-- Waterfall                     October 2011   -> 2012           
 |   +-- documentation                                                      
 |   |   +-- confluence                    April 2017     -> November 2018  
 |   |   +-- dokuwiki                      2017           -> 2019           
 |   |   +-- draw.io                                                        
 |   |   +-- markdown                                                       
 |   +-- ticketing system                                                   
 |       +-- Github issue system           2014           -> 2019           
 |       +-- Jira                          2016           -> 2017           
 |       +-- Redmine                       April 2013     -> June 2013      
 |       +-- Trello                        2013           -> 2019           
 +-- security                                                               
     +-- Access control                                                     
     |   +-- Basic-AUTH                    May 2017       -> 2019           
     |   +-- IPTables                      May 2017       -> 2019           
     |   +-- Netfilter                                                      
     |   +-- VPN                           2017           -> 2019           
     +-- Cryptography                                                       
     |   +-- ECC                                                            
     |   +-- Public Key Infrastructure PKI                                  
     |   +-- RSA                                                            
     |   +-- Secure Socket Layer SSL                                        
     |   +-- Transport Layer Security TLS                                   
     +-- DNSSEC                            October 2018   -> 2019           
     +-- Kali linux                        February 2018  -> April 2018     
     +-- Snort                             April 2018     -> April 2018     
     +-- Wireshark / tcpdump               2014           -> 2019           

Other

Arduino, Chrome extension, DRY Don't repeat yourself, Hugo, IPv6, IaaS, Internet of Things IoT, JQuery, KISS Keep it simple, MVC, NFS, PaaS, Progressive Web App, REST API, RFC, S3, SOAP, SSH, SaaS, UML Unified Modeling Language, Wordpress, back-end, blockchain, data-mining, flask, gcc, integration testing, makefile, mocha, openssh, openssl, routing, unit test, webpack, websockets

Experience

0 1
0 sector IT
1 organization Mijndomein, Lelystad
2 title DevOps
3 timespan December 2016 -> November 2018, 24h p/w
4 employment employee
5 desc Automating operations related tasks and implementing new services. Maintaining the uptime of current services; hosting, email, DNS and upgrade internal configuration tools.
6 activities
  • Developing micro services using Python
  • Enable and connect services to the RabbitMQ message system
  • Optimize operations using Nagios, Elastic search monitoring, Slack notifications
  • Maintenance hosting infrastructure
  • Security audit the infrastructure
  • Ddos intervention
  • Spam and phising email monitoring and prevention
  • Provide software developers with docker platform
  • On-call shift
  • Email platform maintenance
  • Maintenance in data center
7 techniques
  • Scrum/Kanban
  • Python
  • Apache2
  • LXC
  • SQL
  • Docker
  • Kubernetes
  • DC/OS Mesosphere
  • Git
  • Exim
  • KVM
  • Debian Linux
  • AWS EC2
  • RabbitMQ
  • PowerDNS
  • HA-proxy
  • OpenStack
0 1
0 organization OS3, Amsterdam
1 title Covert channel researcher
2 timespan April 2018 -> May 2018, 20h p/w
3 employment edu. project
4 desc Desk research into the possibilities of hiding data in pictures and sharing them on social media. Various social media converted the images (JPG and BMP), destroying the hidden data.
5 activities
  • Embed data using various stenography tools
  • Contribute to an open source stenography tool on Github
  • Uploading various data containing images and downloading for validation
6 techniques
  • Bash
  • Imagemagick
  • LaTeX
  • docker
  • Git
0 1
0 organization OS3, Amsterdam
1 title Blockchain developer
2 timespan February 2018 -> March 2018, 24h p/w
3 employment edu. project
4 projecturl http://github.com/svlentink/logdag
5 desc Classic infrastructures use a central logging server. We created a Proof of Concept which distributes log chunks randomly to other servers and adds a hash of it a blockchain. This makes it infeasible to change the logs.
6 activities
  • Design and implement blockchain architecture
  • Developing a web interface which shows a representation of the graph in real time
  • Writing the backend code in Python
7 techniques
  • Python
  • Docker
  • HTML5
  • Javascript
  • LaTeX
  • D3js
  • Git
0 1
0 organization KPMG, Amstelveen
1 title Blockchain researcher
2 timespan January 2018 -> January 2018, 40h p/w
3 employment thesis
4 desc Most blockchain technologies demand a participant to always be online, in sync with the blockchain. We wrote a paper on the various consensus mechanisms from the blockchain landscape and showed which are applicable on mobile devices.
5 techniques
  • LaTeX
  • Docker
  • Git
0 1
0 organization OS3, Amsterdam
1 title Container technologist
2 timespan November 2017 -> December 2017, 24h p/w
3 employment edu. project
4 projecturl https://github.com/svlentink/container-performance
5 desc One of the new innovations is serverless. Serverless often requires you to rewrite code. We developed an alternative Proof of Concept, which when triggered (REST API, AMQP message) starts a container and returns its output.
6 activities
  • Develop PoC in python
  • Generate performance overview using R
  • Bootstrapping VPSes using Bash
7 techniques
  • Rkt
  • Docker
  • LXC / LXD
  • Python
  • Flask
  • Bash
  • LaTeX
  • R
  • Git
0 1
0 organization OS3, Amsterdam
1 title IoT Security researcher
2 timespan September 2017 -> October 2017, 24h p/w
3 employment edu. project
4 desc Analysing the data flow of IoT (Internet of Things) devices, to get insight into the security and privacy. We looked at multiple devices, looking at the data and to where it connected to.
5 activities
  • Configuration IoT devices
  • Analyse tcpdump using Wireshark
6 techniques
  • Wireshark
  • Tcpdump
  • LaTeX
  • Docker
  • Bash
  • Git
0 1
0 sector IT
1 organization Superbuddy, Zwolle
2 title DevOps
3 timespan June 2016 -> September 2016, 40h p/w
4 employment thesis
5 desc As part of my thesis, I've dockerized their monolith and enabled AB testing by separating components into micr0 services. Adding better monitoring and deployment via CI/CD.
6 activities
  • System recommendations
  • Dockerizing existing applications
  • Implement CI/CD
  • Enable A/B testing using nginx
  • Advise on VPS providers
7 techniques
  • Scrum
  • Git
  • Bash
  • Docker
  • Docker-compose
  • nginx
  • PHP
  • draw.io
  • LaTeX
0 1
0 sector digital journalism
1 organization Blendle, Utrecht
2 title System analyst
3 timespan February 2016 -> May 2016, 40h p/w
4 employment thesis
5 desc To reduce the loading time of the application, I've researched various options to implement caching at different layers. When it was clear that everything had a query parameter and that it could not be solved on the network layer, I looked at bottlenecks in their monolith through static code analysis. After founding two code bugs, I managed to get their monolith working by dockerizing it.
6 activities
  • Creating diagrams of current architecture
  • Dataflow analysis
  • Static code analysis (Ruby)
  • Dockerizing monolith
7 techniques
  • Scrum
  • draw.io
  • LaTeX
  • Ruby
  • Nginx
  • HAproxy
  • CDN Content Delivery Network
  • Javascript
  • REST API
  • HAL JSON
  • Git
0 1
0 sector IT
1 organization imgZine, Amsterdam
2 title DevOps
3 timespan September 2015 -> January 2016, 40h p/w
4 employment internship
5 desc Developing a Proof of Concept backend which is used for chat inside intranet applications. Dockerized an existing XMPP server and compiled it with websocket libraries and developed an HTML5 app which connects to the backend using websockets (RFC7395).
6 activities
  • Developing HTML5 chat client
  • Configure backend
  • Installation script in Bash
7 techniques
  • Scrum
  • Docker
  • HTML5
  • XMPP server
  • Websockets
  • Bash
  • LaTeX
  • Git
0 1
0 sector IT
1 organization Maxedy, Amsterdam
2 title NodeJS developer
3 timespan February 2015 -> June 2015, 40h p/w
4 employment internship
5 desc Deployment using Bash and REST-API in Meteor using OrientDB
6 techniques
  • Scrum
  • OrientDB
  • Node.Js / Javascript
  • REST API
  • Bash
  • NoSQL
  • HTML5
  • draw.io
  • Git
0 1
0 sector retail
1 organization Iceberg Webshophands, Dronten
2 title Grails developer
3 timespan November 2013 -> January 2014, 40h p/w
4 employment internship
5 desc Proof of Concept; developing online craigslist for fresh food
6 techniques
  • Scrum
  • Bash
  • Java
  • HTML
  • SQL
  • Grails
  • Git
0 1
0 organization Windesheim, Zwolle
1 title PHP developer
2 timespan September 2011 -> December 2011, 30h p/w
3 employment edu. project
4 desc Development of two websites in teams
5 techniques
  • MySQL
  • PHP5
  • svn
0 1
0 sector energy
1 organization Total Wind, Dronten
2 title Wind turbine mechanic
3 timespan February 2011 -> July 2011, 40h p/w
4 employment internship
0 1
0 sector industrial
1 organization Engels en de Beer, Lelystad
2 title Electrical engineer
3 timespan January 2010 -> January 2011, 8h p/w
4 employment employee
5 desc Side job, creating switch cabinets for machines used in food factories
0 1
0 sector food
1 organization Iscal sugar, Lelystad
2 title Machine maintenance
3 timespan 2009 -> 2011, 8h p/w
4 employment employee
5 desc Side job, part of the technical department in a food factory