Felix Heller - App Engineer

Q: Where is Felix based?

Felix is based in Darmstadt, Germany .

Q: What languages does Felix speak?

Felix speaks the following languages: German (Native), English (Advanced), French (Intermediate), Spanish (Elementary) .

Q: How many years of experience does Felix have?

Felix has at least 12 years of experience. During this time, Felix has worked in at least 9 different roles and for 12 different companies . The average length of individual experience is 1 year and 11 months . Note that Felix may not have shared all experience and actually has more experience.

Q: What is Felix's latest experience?

Felix's most recent position is App Engineer at Merck KGaA .

Q: What companies has Felix worked for in recent years?

In recent years, Felix has worked for Merck KGaA , ALRE-IT Regeltechnik GmbH , Active Artware GmbH , Self-employed , and NC Computer .

Q: Which industries is Felix most experienced in?

Felix is most experienced in industries like Information Technology (IT) , Chemical , and Arts and Crafts . Felix also has some experience in Biotechnology , Pharmaceutical , and Real Estate .

Q: Which business areas is Felix most experienced in?

Felix is most experienced in business areas like Information Technology (IT) , Product Development , and Logistics . Felix also has some experience in Research and Development (R&D) .

Q: Which industries has Felix worked in recently?

Felix has recently worked in industries like Information Technology (IT) , Chemical , and Arts and Crafts .

Q: Which business areas has Felix worked in recently?

Felix has recently worked in business areas like Information Technology (IT) , Product Development , and Logistics .

Recommended expert

Darmstadt, Germany

Experience

Oct 2024 - Present

1 year 5 months

App Engineer

Merck KGaA

Further development of various apps in the context of a Digital Trust Framework / IIoT
Programming language: Dart
Technologies & frameworks: Flutter, Stacked, CI/CD

Mar 2024 - Jul 2024

5 months

Android App Engineer

ALRE-IT Regeltechnik GmbH

Development of an app to control thermostats
Programming language: Dart
Technologies & frameworks: Flutter, Riverpod, NFC communication

Feb 2024 - Dec 2024

11 months

Frontend Engineer

Active Artware GmbH

Further development of intranet websites for a large chemical company
Programming languages: TypeScript, C#, HTML, LESS
Technologies & frameworks: Angular, ASP.NET, REST APIs

Oct 2023 - Dec 2023

3 months

Android App Engineer

Self-employed

Developed a new open source app to help reduce smartphone use
Fully open source with over 180 "stars" on GitHub
Programming language: 100% Kotlin
Technologies & frameworks: Jetpack Compose, MVVM, Hilt Dependency Injection, Material 3, DataStore

Aug 2023 - Sep 2023

2 months

Android App Engineer

NC Computer

Developed a new Android app to optimize warehouse logistics processes for a fire door manufacturer
App for batch uploading photos over a network, linking them to an order through QR code scanning
Programming language: 100% Kotlin
Technologies & frameworks: Jetpack Compose, Kotlin Coroutines, Material 3, DataStore, JCIFS

Jan 2023 - Jun 2023

6 months

Mobile App Engineer

velocate / PSP Pauli Services & Products GmbH

Further development of an app for GPS trackers and caravan sensor monitoring systems
App for monitoring and locating caravans, controlling and reading various sensors (e.g., tire pressure, gas level)
Rebuilding the same app in Flutter
Programming languages: Dart; JavaScript, SCSS
Technologies & methods: Flutter, Riverpod, GoRouter, Hive, Freezed; NativeScript, VueJS, OneSignal/Firebase; Git, agile development, Jira

Jul 2022 - Aug 2022

2 months

Cloud Software Engineer

Save The Children

Support in developing Salesforce and Talend applications
Integrating Java software with the Talend Cloud
Programming languages: Java, JS
Technologies & methods: Salesforce Marketing Cloud

Jan 2022 - Dec 2022

1 year

Frontend Engineer

Immomio GmbH

Development of a new app for housing company tenants to retrieve documents and messages, update their personal data, and report damages in their apartment
Programming the UI based on Figma templates and connecting the screens to the backend
Programming the module for reporting damages using a dynamic, path-dependent, and backend-configurable questionnaire
Generalization of UI components for whitelabeling the app
Programming languages: TypeScript, SCSS
Technologies & methods: NativeScript, Angular 12, GraphQL, NGRX, Git, CI/CD, Test Automation; Scrum, Scaled Agile (SAFe), Jira, Figma

Aug 2021 - Dec 2021

5 months

Frontend Engineer

DIT Deutsche Immobilien IT & Marketing GmbH

Maintenance of a legacy app for housing company tenants (similar to Immomio)
Programming languages: JS, HTML5, CSS
Technologies & methods: Apache Cordova, Git

Jan 2021 - Dec 2022

2 years

Webmaster

Meeting Of Styles Wiesbaden

Redesign and further development of the website
Programming the theme and online shop
Connecting the website to existing databases for automated content generation
Programming languages: PHP, JS, HTML5, CSS
Technologies & methods: WordPress, WooCommerce, Integromat, Airtable

Jan 2021 - Feb 2021

2 months

Research Assistant

Johannes Gutenberg-Universität Mainz

Developed a module for conducting online studies
Programming languages: JS, HTML5, CSS

Oct 2015 - Mar 2016

6 months

Android Developer & Frontend Engineer

CoSee GmbH

Further development of an Android app and new development of a web portal for online lending of eBooks and Audiobooks
Development of the e-reader component and the audio player
Integration of test frameworks using Jenkins
Programming languages: Kotlin, Java, JS, HTML5, CSS
Technologies & methods: ExoPlayer, ReactJS, Butterknife, Retrofit, OrmLite, Git Flow, Scrum, Retrospectives, Weekly meetings, JIRA, Jenkins

Mar 2014 - Present

12 years

Android App Developer

Self-employed

AlcoTrack: Android app to track alcohol consumption with over 200,000 downloads and translated into 17 languages, average rating 4.6 stars
DetoxDroid: open-source Android app to reduce smartphone usage with over 180 stars on GitHub
CheatDroid: Android app for 'hacking' app settings with over 2 million downloads
Developed a web tool for collaborative translation of Android apps with an API link to the Google Play Store for automatic transfer of translations to the store
Programming languages: Dart, Kotlin, Java, Python, HTML5, CSS, PHP, JS
Technologies & methods: Flutter, MVVM, Jetpack Compose, Git, code generation, unit tests, Guava, GSON, Fat-Free PHP, WordPress, jQuery, Bootstrap, BLoC

Industries Experience

See where this freelancer has spent most of their professional time. Longer bars indicate deeper hands-on experience, while shorter ones reflect targeted or project-based work.

Experienced in Information Technology (12 years), Chemical (2 years), Arts and Crafts (2 years), Biotechnology (1.5 years), Pharmaceutical (1.5 years), and Real Estate (1.5 years).

Information Technology

Chemical

Arts and Crafts

Biotechnology

Pharmaceutical

Real Estate

Business Areas Experience

The graph below provides a cumulative view of the freelancer's experience across multiple business areas, calculated from completed and active engagements. It highlights the areas where the freelancer has most frequently contributed to planning, execution, and delivery of business outcomes.

Experienced in Information Technology (12 years) and Product Development (12 years).

Information Technology

Product Development

Skills

Programming Languages: Kotlin, Java, Python, Dart, Php, Html5, Js, (S)css, Sql
Methods: Scrum, Scaled Agile (Safe), Kanban, Clean Code, Ci/cd, Solid, Design Patterns, Architectural Documentation
Frameworks / Technologies: Flutter, Angular 12, Vue, Jetpack Compose, Nativescript, Bluetooth Low Energy (Ble), Firebase, Figma, Riverpod, Jenkins, Appium, Ci/cd, Libgdx, Laravel, Fat-free Php, Bootstrap, Jquery, Node.js, Express.js, Mongodb, Wordpress, Apache Cordova, Swagger/openapi
Software: Android Studio / Intellij Idea, Git, Gimp, Ableton Live
Industry Knowledge: Web Development, Data Science, It Security, Google Material Design, Web Crawling, Real Estate Industry

Languages

German

Native

English

Advanced

French

Intermediate

Spanish

Elementary

Education

Apr 2016 - Sep 2019

TU Darmstadt

M. Sc. · Business Informatics · Darmstadt, Germany · 1,35

Oct 2012 - Oct 2015

TU Darmstadt

B. Sc. · Business Informatics · Darmstadt, Germany · 2,10

Apr 2012 - Oct 2012

Johannes Gutenberg-Universität Mainz

Computer Science · Mainz, Germany

...and 1 more

Certifications & licenses

Android LinkedIn skill test

Angular LinkedIn skill test

Java LinkedIn skill test

Kotlin LinkedIn skill test

Profile

Created

January 2026

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Frequently asked questions

Do you have questions? Here you can find further information.

Where is Felix based?

Felix is based in Darmstadt, Germany.

What languages does Felix speak?

Felix speaks the following languages: German (Native), English (Advanced), French (Intermediate), Spanish (Elementary).

How many years of experience does Felix have?

Felix has at least 12 years of experience. During this time, Felix has worked in at least 9 different roles and for 12 different companies. The average length of individual experience is 1 year and 11 months. Note that Felix may not have shared all experience and actually has more experience.

What roles would Felix be best suited for?

Based on recent experience, Felix would be well-suited for roles such as: App Engineer, Android App Engineer, Frontend Engineer.

What is Felix's latest experience?

Felix's most recent position is App Engineer at Merck KGaA.

What companies has Felix worked for in recent years?

In recent years, Felix has worked for Merck KGaA, ALRE-IT Regeltechnik GmbH, Active Artware GmbH, Self-employed, and NC Computer.

Which industries is Felix most experienced in?

Felix is most experienced in industries like Information Technology (IT), Chemical, and Arts and Crafts. Felix also has some experience in Biotechnology, Pharmaceutical, and Real Estate.

Which business areas is Felix most experienced in?

Felix is most experienced in business areas like Information Technology (IT), Product Development, and Logistics. Felix also has some experience in Research and Development (R&D).

Which industries has Felix worked in recently?

Felix has recently worked in industries like Information Technology (IT), Chemical, and Arts and Crafts.

Which business areas has Felix worked in recently?

Felix has recently worked in business areas like Information Technology (IT), Product Development, and Logistics.

What is Felix's education?

Felix holds a Master in Business Informatics from TU Darmstadt and a Bachelor in Business Informatics from TU Darmstadt.

Does Felix have any certificates?

Felix has 4 certificates. Among them, these include: Android LinkedIn skill test, Angular LinkedIn skill test, and Java LinkedIn skill test.

What is the availability of Felix?

Felix is immediately available for suitable projects.

What is the rate of Felix?

Felix's rate depends on the specific project requirements. Please use the Meet button on the profile to schedule a meeting and discuss the details.