Felix Heyn-Jonhsen

Felix Heyn-Johnsen

Senior Developer


Developer of backend systems and services using functional programming, with experience automating IT and administration tasks.

I have done a fair deal of integration and import/export of data, along with investigating undocumented procedures.

I prefer projects on the more technical side, preferably with open-source tools and technologies.

Key Skills

  • Scala + sbt 3 years
  • Akka 3 years
  • python 3 years
  • HTTP 10+ years, including Apache, nginx, developing webservices and websites
  • MySQL, 10+ years
  • Vagrant, 3 years
  • Jenkins 3 years
  • Java 3 years
  • Linux 10+ years
  • Ruby 5 years, for anything from scripts to RESTful webservices using passenger, sinatra, ActiveRecord and ActiveLDAP and SMPP protocol testing
  • PHP 8 years

Work Experience

Developer at Intellifinder A/S

sept. 2020 - present

Developing features and doing bugfixes on our main application, an Angular SPA talking to an (almost) RESTful backend (PHP + Angular + mongodb + OAuth/Keycloak)

Developing features for our mobile apps (iOS + Android) using angular + cordova. Maintaining automated build system (Bitrise). Managing approval and release of mobile apps

Setup of CI/CD (Bitbucket-pipelines) for deployment to beoth legacy stand alone servers and kubernetes on google cloud.

Doing evaluation of pentesting-software and miscellaneous operations/maintenance tasks, mainly in python or bash

Developer at AutoProff A/S

nov 2019 - sept 2020

Bugfixing and developing features on main application (PHP, both with Laravel and legacy, Vue + Auroradb + docker)

Developing internal information system using Vue, websockets, Laravel-Vapor

ETL system for vehicle-data (Danish "motorregistret") into nosql, using AWS (lambda, batch, glue, dynamodb, api-gateway) + docker + CircleCI

PDF ripper: a C# + .net framework, webservice for data extraction using Pidgin parser-combinators and AWS Textract, setup of automatic deployment github -> Azure. Testing done using nUnit.

Developer at improving

june 2019 - okt 2019

Development and updating of Magento webshops (PHP+MySQL+Linux)

Developing and maintaining frontend systems (Vue+javascript+html)

Developer at vemcogroup

jan 2019 - mar 2019

Refactoring PHP/Laravel code using PHPUnit

Automated excel-export, Postgres and Influxdb testing

Senior systems developer at LINK Mobility

may 2015 - september 2018

Primarily developed backend software (Linux daemons) written in Scala and Java.

Developed the main message-sender: Receive and emit message-jobs via http or from database, implements features (recipient-lists and message templates), throttles messages and prioritizes them (fairness for users who send few messages vs. users who send many), queueing system for high-load scenarios. This eliminated delays for high priority messages (for example passcodes) during high-load scenarios.

Implemented a pseudo “DSL” for message filtering and transform, used for spam-filtering and traffic-routing to save costs. This changed the process from releasing a new version of software, to simply editing some database entries representing the rules whenever a business-change was necessary.

Developed services for receiving and parsing SOAP-formatted MMS-messages.

Developed service for sending message-receipts/reports to HTTP endpoints of customers (i.e. to webservices that are sometimes slow or unreliable)

Various import/export tasks for customer-data using ruby and Scala.

Minor debugging and bugfixing of SMPP-software.

Developer at IPW systems

May 2014 - April 2015

Developed core and customer specific solutions for Metazo, an in house QA/ISO9000 web-based software using PHP+MySQL.

Made an automated installer for the customer-hosted version of Metazo using Powershell.

Implemented E-conomic invoicing using REST+SOAP.

Minor systemadministration and network tasts, migrated hosted sites using python-scripts.

Developer at CoolSMS/CoolSystems

January 2013 - April 2014

PHP (Codeigniter, CakePHP) + MySQL + jQuery, primarily for inhouse systems.

Implemented restaurant booking and planning system backend for Gezto.dk

Ruby + Sinatra, REST-API for contact and contact-lists.

Refactored a WindowsPhone app (streaming audio, C#) and got it approved on the app store.

DevOps at IT-University Copenhagen

May 2008 - December 2012

Mitigated the complexity of 3 directories (OpenLDAP + win2003AD + win2008AD). Developed a solution where they were combined and syncronized using ActiveLDAP (ruby) and exposed as a REST webservice using Sinatra (ruby)

Transformed the account creation process from various manual scripts and processes, into a fully automated precess. It involved reading and writing files, databases and LDAP/AD directories for the various administration and IT systems (using perl, python, php, ruby) involved when creating a new employee or student account.

Implemented WiFi (EDUROAM) using Freeradius + 802.1X + 802.1Q. Employees and students had separate VLANs provisioned.

Various systemadministration tasks, VMWare, SAN, procurve+Aerohive network/wifi. ActiveDirectory, OpenLDAP, Linux, Apache, firewalls.

DevOps at Furesøhøj

October 2004 - December 2006

Various programming and IT-related tasks, using mainly FreeBSD, PHP and MySQL.

Developed features for the main administration and invoicing system (PHP+MySQL) for CopyGene Aps.

Administering network (procurve) and firewall (FreeBSD ipfw) for CopenhagenOfficeHotels.

Developer at produktionsselskabet/Zentropa

September 2005 - November 2005

Developed administration and forecasting system using PHP and MySQL.




T6 IT-sikkerhed



Bachelor degree, information technology. Information technology with some mathematical modelling for image/video analysis. Example: http://stalinize.heynjohnsen.dk

Aalborghus Gymnasium


Mathematical student

Personal Profile

Reads and writes Danish (native language) and English (full professional proficiency).

Married with 3 children.

My spare time is used reading books and strengthtraining.