Freelance Data / DevOps / Fullstack / Linux engineer

0 1
0 name ing. Sander Lentink, MSc.
1 currentcity Lelystad
2 phone +31617012655
3 email sv@lent.ink
4 links
  • 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 deepen my experience with container orchestration (kubernetes) and like it when my work incorporates data science, security and writing code.

Experience

0 1
0 role Cloud Architect | Rabobank (banking), Utrecht
1 timespan November 2019 -> June 2020, 40h p/w (consultant)
2 desc As part of the strategic move away from own data centers (DC) to the Cloud, I helped with setting up the infrastructure for the pilot application (Pega) by creating the automated rollout of a kubernetes (k8s) cluster including the application. We were responsible for designing and executing the first migration, in which I directed the implementation of Infrastructure as Code (IaC) using Terraform.
3 activities
  • Constant evaluation of business value vs. engineer's wishes for technical improvements
  • Design of Infrastructure as Code (IaC) environment
  • Integrate security principles in IaC, k8s and processes
  • Develop standards and modules in Terraform
  • Optimize CI/CD pipelines and its templates
  • Automate deployment on Azure using Terraform and pipelines
  • Convert existing installation guide to IaC
  • Perform Database tests as part of selection process
  • Direct the IaC team
  • Assisting team with Terraform and container questions
4 techniques
  • Scrum
  • Kubernetes
  • Terraform
  • Azure DevOps
  • Python
  • Dockerfile
  • Linux
  • CI/CD
  • Git
  • PostgreSQL
  • Azure
  • Pega (Java)
  • Infrastructure as Code (IaC)
0 1
0 role Network engineer | Surfnet (research), Utrecht
1 timespan October 2019 -> November 2019, 40h p/w (thesis)
2 projecturl http://tunroam.org
3 desc Created wireless protocol that allows the creating of secure public WiFi access points by whitelisting VPN traffic.
4 activities
  • Modifying 802.1x authentication server to support protocol
  • Design wireless protocol
  • Implement protocol on a Raspberry Pi, making it a wireless Access Point
5 techniques
  • draw.io
  • LaTeX
  • FreeRADIUS
  • Python
  • Markdown
  • Javascript
  • Git
  • Debian Linux
  • Docker
  • Bash
  • Raspberry Pi
  • Orange Pi
  • Armbian
0 1
0 role DevOps engineer | Rabobank (banking), Utrecht
1 timespan March 2019 -> October 2019, 24h p/w (consultant)
2 desc As part of the strategic move away from own data centers (DC) to the Cloud, I rationalized the on premise infrastructure. For this I used Infrastructure as Code (IaC) principles to create a manageable middleware to request resources in their private DC.
3 activities
  • Strategize transition to containers, to facilitate transition to the Cloud
  • Research options to request resources via ManageIQ using Infrastructure as Code (IaC)
  • Creating ManageIQ Terraform provider using Golang
  • Develop new readable Terraform modules following AWS syntax
  • Develop data parsers in Python for on premise DC management
  • Create coupling between DevOps tools and APIs
  • Optimizing existing IaC templates (YAML and JSON)
  • Containerize Pega using Dockerfile (creation of golden image)
  • Creating platform design drawings
  • Assisting team with Python, Linux, containers, routing and Terraform questions
  • Presenting insights and designs to teams
4 techniques
  • Scrum
  • Terraform
  • Docker
  • Python
  • Ansible
  • Alpine Linux
  • ManageIQ
  • Git
  • Go (golang)
  • Redhat
  • Bitbucket
  • Confluence
  • Infrastructure as Code (IaC)
0 1
0 role DevOps Engineer | Mijndomein (IT), Lelystad
1 timespan December 2016 -> November 2018, 24h p/w (employee)
2 desc Automating operations related tasks and implementing new services. Maintaining the uptime of current services; hosting, email, DNS and upgrade internal configuration tools.
3 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
4 techniques
  • Scrum
  • Kanban
  • Python
  • Apache
  • LXC
  • SQL
  • Docker
  • Kubernetes
  • DC/OS Mesosphere
  • Git
  • Exim
  • KVM
  • Debian Linux
  • AWS EC2
  • RabbitMQ
  • PowerDNS
  • HA-proxy
  • OpenStack
  • Kibana
  • Dokuwiki
0 1
0 role Covert channel researcher | OS3 (education), Amsterdam
1 timespan April 2018 -> May 2018, 20h p/w (edu. project)
2 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.
3 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
4 techniques
  • Bash
  • Imagemagick
  • LaTeX
  • Docker
  • Git
0 1
0 role Blockchain developer | OS3 (education), Amsterdam
1 timespan February 2018 -> March 2018, 24h p/w (edu. project)
2 projecturl http://github.com/svlentink/logdag
3 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.
4 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
5 techniques
  • Python
  • Docker
  • HTML5
  • Javascript
  • LaTeX
  • D3js
  • Git
  • Dokuwiki
0 1
0 role Blockchain researcher | KPMG (education), Amstelveen
1 timespan January 2018 -> January 2018, 40h p/w (thesis)
2 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.
3 techniques
  • LaTeX
  • Docker
  • Git
0 1
0 role Container technologist | OS3 (education), Amsterdam
1 timespan November 2017 -> December 2017, 24h p/w (edu. project)
2 projecturl https://github.com/svlentink/container-performance
3 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.
4 activities
  • Develop PoC in python
  • Generate performance overview using R
  • Bootstrapping VPSes using Bash
5 techniques
  • Rkt
  • Docker
  • LXC / LXD
  • Python
  • Flask
  • Bash
  • LaTeX
  • R
  • Git
0 1
0 role IoT Security researcher | OS3 (education), Amsterdam
1 timespan September 2017 -> October 2017, 24h p/w (edu. project)
2 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.
3 activities
  • Configuration IoT devices
  • Analyse tcpdump using Wireshark
4 techniques
  • Wireshark / tcpdump
  • LaTeX
  • Docker
  • Bash
  • Git
  • Dokuwiki
0 1
0 role DevOps Engineer | Superbuddy (IT), Zwolle
1 timespan June 2016 -> September 2016, 40h p/w (thesis)
2 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.
3 activities
  • System recommendations
  • Dockerizing existing applications
  • Implement CI/CD
  • Enable A/B testing using nginx
  • Advise on VPS providers
4 techniques
  • Scrum
  • Git
  • Bash
  • Docker
  • Docker-compose
  • Nginx
  • PHP
  • draw.io
  • LaTeX
  • Gitlab
0 1
0 role System analyst | Blendle (digital journalism), Utrecht
1 timespan February 2016 -> May 2016, 40h p/w (thesis)
2 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.
3 activities
  • Creating diagrams of current architecture
  • Dataflow analysis
  • Static code analysis (Ruby)
  • Dockerizing monolith
4 techniques
  • Scrum
  • draw.io
  • LaTeX
  • Ruby
  • Nginx
  • HAproxy
  • CDN Content Delivery Network
  • Javascript
  • REST API
  • HAL JSON
  • Git
0 1
0 role DevOps | imgZine (IT), Amsterdam
1 timespan September 2015 -> January 2016, 40h p/w (internship)
2 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 WebSocket (RFC7395).
3 activities
  • Developing HTML5 chat client
  • Configure backend
  • Installation script in Bash
4 techniques
  • Scrum
  • Docker
  • HTML5
  • XMPP server
  • WebSocket
  • Bash
  • LaTeX
  • Git
0 1
0 role NodeJS developer | Maxedy (IT), Amsterdam
1 timespan February 2015 -> June 2015, 40h p/w (internship)
2 desc Deployment using Bash and REST-API in Meteor using OrientDB
3 techniques
  • Scrum
  • OrientDB
  • Node.js
  • Javascript
  • REST API
  • Bash
  • NoSQL
  • HTML5
  • draw.io
  • Git
  • Mocha
0 1
0 role Grails developer | Iceberg Webshophands (retail), Dronten
1 timespan November 2013 -> January 2014, 40h p/w (internship)
2 desc Proof of Concept; developing online craigslist for fresh food
3 techniques
  • Scrum
  • Bash
  • Java
  • HTML5
  • SQL
  • Grails
  • Git
0 1
0 role PHP developer | Windesheim (education), Zwolle
1 timespan September 2011 -> December 2011, 30h p/w (edu. project)
2 desc Development of two websites in teams
3 techniques
  • MySQL
  • PHP5
  • svn

Education

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

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                                          
 |   |   +-- Azure DevOps                      November 2019  -> 2020           
 |   |   +-- Gitlab                            August 2018    -> November 2018  
 |   |   +-- Travis                            February 2017  -> October 2018   
 |   +-- Infrastructure as Code IaC                                             
 |   |   +-- Ansible                           March 2017     -> August 2019    
 |   |   +-- Terraform                         November 2018  -> 2020           
 |   +-- Version Control Systems VCS                                            
 |       +-- Git                               2013           -> 2020           
 |       |   +-- Gitlab                                                         
 |       |   +-- Github                                                         
 |       |   +-- Bitbucket                                                      
 |       +-- svn                               2012           -> 2013           
 +-- containers                                                                 
 |   +-- Docker                                February 2015  -> 2020           
 |   +-- LXC                                   March 2017     -> 2018           
 |   |   +-- LXD                               November 2017  -> 2018           
 |   +-- Rkt                                   November 2017  -> December 2017  
 |   +-- container orchestration                                                
 |       +-- DC/OS Mesosphere                  February 2017  -> November 2018  
 |       +-- Kubernetes                        June 2018      -> 2020           
 |       +-- Microservices                     June 2016      -> 2018           
 +-- 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   -> 2020           
 |   |   +-- NoSQL                                                              
 |   |   |   +-- MongoDB                       July 2016      -> October 2018   
 |   |   |   +-- OrientDB                      March 2015     -> June 2015      
 |   |   +-- PostgreSQL                                                         
 |   |   +-- SQL server                        2012           -> 2013           
 |   +-- formats                                                                
 |       +-- AMQP / RabbitMQ                   February 2017  -> 2020           
 |       +-- JSON                                                               
 |       +-- XML                                                                
 |       +-- YAML                                                               
 +-- infrastructure                                                             
 |   +-- FreeRADIUS                            October 2019   -> December 2019  
 |   +-- Linux                                                                  
 |   |   +-- Alpine Linux                      2016           -> 2020           
 |   |   +-- Redhat                            April 2019     -> August 2019    
 |   |   +-- Ubuntu / Debian                   2012           -> 2020           
 |   +-- OpenStack                             January 2017   -> February 2017  
 |   +-- VM                                                                     
 |   |   +-- KVM                               February 2017  -> October 2018   
 |   |   +-- Xen                               November 2017  -> 2020           
 |   +-- cloud                                                                  
 |   |   +-- AWS Amazon Web Services           February 2017  -> November 2018  
 |   |   +-- DNS                               2016           -> 2020           
 |   |   |   +-- bind                          September 2018 -> October 2018   
 |   |   +-- Load balancing                    July 2017      -> September 2018 
 |   |   |   +-- HA-proxy                      March 2016     -> October 2018   
 |   |   +-- Microsoft Azure                   June 2019      -> June 2020      
 |   |   +-- Reverse / TLS proxy                                                
 |   |       +-- Apache                        January 2017   -> September 2018 
 |   |       +-- Nginx                         2015           -> 2020           
 |   +-- monitoring and alerting                                                
 |       +-- Elastic Search                    April 2017     -> July 2018      
 |       |   +-- Kibana                                                         
 |       |   +-- Logstash / grok               November 2017  -> December 2017  
 |       +-- Email                                                              
 |       |   +-- Exim                          April 2017     -> 2019           
 |       |   +-- smarthost                                                      
 |       +-- Nagios                            December 2016  -> November 2018  
 |       +-- Slack API                         2017           -> 2018           
 +-- languages                                                                  
 |   +-- Bash                                  February 2015  -> 2020           
 |   +-- C#                                    January 2013   -> June 2013      
 |   +-- CSS3                                  October 2011   -> 2020           
 |   +-- Go (golang)                           June 2019      -> September 2019 
 |   +-- HTML5                                 September 2011 -> 2020           
 |   +-- Java                                  April 2012     -> January 2014   
 |   +-- Javascript                            February 2015  -> 2020           
 |   +-- LaTeX                                 2014           -> 2019           
 |   +-- Node.js                               February 2015  -> 2018           
 |   +-- PHP                                   September 2011 -> June 2012      
 |   +-- Python                                February 2017  -> 2020           
 |   +-- R                                     November 2017  -> March 2018     
 |   +-- Ruby                                  February 2016  -> May 2016       
 |   +-- SQL                                   September 2011 -> 2020           
 +-- process management                                                         
 |   +-- SDLC                                                                   
 |   |   +-- Agile                                                              
 |   |   |   +-- Kanban                        2013           -> 2020           
 |   |   |   +-- Scrum                         April 2013     -> 2020           
 |   |   |   +-- User stories                                                   
 |   |   +-- Waterfall                         October 2011   -> 2012           
 |   +-- documentation                                                          
 |   |   +-- Confluence                        April 2017     -> October 2019   
 |   |   +-- Dokuwiki                          2017           -> 2019           
 |   |   +-- Markdown                                                           
 |   |   +-- draw.io                                                            
 |   +-- ticketing system                                                       
 |       +-- Github issue system               2014           -> 2020           
 |       +-- Jira                              2016           -> 2019           
 |       +-- Redmine                           April 2013     -> June 2013      
 |       +-- Trello                            2013           -> 2018           
 +-- security                                                                   
     +-- Access control                                                         
     |   +-- Basic-AUTH                        May 2017       -> 2020           
     |   +-- IPTables                          May 2017       -> 2019           
     |   +-- Netfilter                                                          
     |   +-- VPN                               2017           -> 2020           
     +-- Cryptography                                                           
     |   +-- Elliptic-curve 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

AWS S3, Arduino, Chrome extension, DRY Don't repeat yourself, Flask, FreeRADIUS, Hugo, IPv6, IaaS, Internet of Things IoT, JQuery, KISS Keep it simple, Model View Controller (MVC), NFS, OpenSSH, OpenSSL, PaaS, Progressive Web App (PWA), REST API, RFC, SOAP, SSH, SaaS, Unified Modeling Language (UML), Wordpress, back-end, blockchain, data-mining, gcc, integration testing, makefile, routing, unit test, webpack

Techniques

Alpine Linux, AMQP / RabbitMQ, Ansible, Apache, Arduino, Armbian, Autodesk Inventor, AWS Amazon Web Services, AWS EC2, AWS S3, Azure, Azure DevOps, back-end, Bash, Basic-AUTH, Bitbucket, blockchain, C#, CDN Content Delivery Network, Chrome extension, CI/CD, Confluence, CSS3, D3js, data-mining, DC/OS, DC/OS Mesosphere, Debian Linux, DNS, DNSSEC, Docker, Docker-compose, Dockerfile, Dokuwiki, draw.io, DRY Don't repeat yourself, Elastic Search, Elliptic-curve cryptography (ECC), Excel, Exim, Flask, FreeRADIUS, gcc, Git, Github issue system, Gitlab, Go (golang), Grails, HA-proxy, HAL JSON, HAproxy, HTML5, Hue, Hugo, IaaS, Imagemagick, Impala, Infrastructure as Code (IaC), integration testing, Internet of Things IoT, IPTables, IPv6, Java, Javascript, Jenkins, Jira, JQuery, JSON, Kafka, Kali linux, Kanban, Kibana, KISS Keep it simple, Kubernetes, KVM, LaTeX, Lego, Linux, Load balancing, LXC, LXC / LXD, makefile, ManageIQ, Markdown, Memcache, Mesos Marathon, metal frame construction, Microservices, Microsoft Azure, Mocha, Model View Controller (MVC), MongoDB, MySQL, MySQL / MariaDB, Nagios, Netfilter, NFS, Nginx, Nifi, Node.js, NoSQL, Numpy, OpenSSH, OpenSSL, OpenStack, Orange Pi, OrientDB, PaaS, Pandas, Pega (Java), PHP, PHP5, PostgreSQL, PowerDNS, Progressive Web App (PWA), Public Key Infrastructure (PKI), Python, R, RabbitMQ, Raspberry Pi, Redhat, Redis, Redmine, REST API, RFC, Rkt, routing, RSA, Ruby, SaaS, Scrum, Secure Socket Layer (SSL), sheet metal, Slack API, smarthost, Snort, SOAP, SQL, SQL server, SSH, svn, Terraform, Transport Layer Security (TLS), Travis, Trello, Ubuntu / Debian, Unified Modeling Language (UML), unit test, User stories, Visual studio, VPN, Waterfall, web scraping, webpack, WebSocket, welding, Wireshark / tcpdump, Wordpress, Xen, XML, XMPP server, YAML