Lead Full-stack Developer | CTO
2021 - 2022Navarc- Completely redesigned the database architecture into a simpler model.
- Refactored the back end from scratch into a cleaner, maintainable project.
- Optimized and managed the infrastructure alone. Along with the two previous measures, this led to a decrease in infrastructure costs of 70%.
- Introduced best practices, including a proper Gitflow, documentation, and test suite.
- Code reviewed all pull requests and provided thorough follow-up feedback to ensure the growth of team members.
- Guided all feature-related decisions to ensure technical efficiency and optimal UI/UX.
Technologies: Python, Flask, Google Cloud Platform (GCP), Firebase, BigQuery, PostgreSQL, TypeScript, Devtron, Argo CD, REST APIs, SQLAlchemyCo-founder and Full-stack Developer
2019 - 2021Zappr- Designed the app structure to allow scaling and included all features of a complete social networking application, such as image and video caching and preloading, push notifications, an integrated camera, and a chat.
- Developed and debugged the complete application alone.
- Shipped the application into production on Android and iOS and deployed the back-end containerized apps into a Kubernetes environment.
Technologies: Python, Django, Android, Flutter, NGINX, Kubernetes, Firebase, Dart, Full-stack, WebSockets, REST APIs, Django REST Framework, iOS, SwiftArea Manager
2017 - 2019Zalando- Created KPIs during the ramp-up phase of a new Zalando logistics warehouse.
- Created and implemented processes that improved productivity and quality delivered as well as the co-workers' safety.
- Managed 150 to 200 people, including disciplinary responsibility. The objective was to permanently maintain and improve the co-workers' motivation by performing monthly feedbacks and advancement.
- Planed and coordinated FTEs to optimally achieve the goals and guarantee transparent communication with internal and external partners.
- Created and programed ad-hoc software in Python, JavaScript (used in Google Sheets), and VBA according to my firm's needs.
Technologies: Management, Change Management, Leadership, Team Leadership, Lean Project Management, Lean, Process Management, Python, Python 3, JavaScript, Google Sheets, Google Sheets API, Excel VBATeaching Fellow
2016 - 2016University of Strasbourg- Provided lectures in controlling as a teaching fellow at the University of Strasburg for 4th-semester students.
- Created new exercises and tests covering specific topics.
- Assessed mid-term tests and final exams as part of my role.
Technologies: Controlling, University TeachingFreelance Developer
2015 - 2015Freelance- Developed a tailor-made database management software programmed in VBA for a client used by around 200 users.
- Organized meetings with end users in order to define the project specifications. Established an FAQ and step-by-step tutorial covering all functionalities of the application.
- Provided six months warranty (e.g., bug fixing) and end-user training of key users.
Technologies: Excel VBAAssistant Project Manager
2014 - 2015Daimler AG- Assisted the project manager in his daily tasks during the pre-project phase of the plant's migration towards a new ERP (SAP). Tasks included implementing the SAP project throughout all its essential phases, milestones, workshops, and meetings.
- Took care of financial issues and summarized the expenses for internal reporting purposes.
- Supervised the call for tenders, analyzed various offers to select the ideal service provider, and drafted the project's contract.
- Wrote a thesis which aimed at analyzing the plant's situation in terms of change management, a field in which I made several recommendations.
Technologies: Project Management Office (PMO), Change ManagementPMO Intern
2014 - 2014Hugo Boss- Coordinated new orders coming from the Benelux of France autonomously to construct Hugo Boss shops and stores.
- Calculated cost estimations according to benchmarks and assisted cost and invoice control.
- Ordered via SAP and organized transportation of shop components.
- Created cross-departmental tools to automate cost extensive administrative tasks in Excel VBA and more generally solved any Excel-related problem.
Technologies: Project Management Office (PMO), Excel VBA
Jonas Schalck
Full-stack Developer in Strasbourg, France
Member since September 28, 2021
Jonas is a passionate full-stack mobile developer; he loves everything about programming, from researching to scripting, designing, and building solutions for clients. Using his favorite technologies, he single-handedly developed a social networking application that is now in production. Thanks to his work experience as a manager, Jonas demonstrates excellent soft skills, making communicating with him a painless process.
Jonas is now available for hire
Availability
Part-time
Preferred Environment
Ubuntu, Android Studio, PyCharm
The most amazing...
...project I've developed is Zappr, a fully functional social network mobile application.
Employment
Experience
- Zappr
A complete social networking application that was written with Flutter. The API back end is written in Python using the Django framework.
I was the sole developer on the project, which means I had to manage every step of the process, from designing its structure to shipping it into production.
Skills
Languages
Python, Dart, Excel VBA, Python 3, Kotlin, JavaScript, TypeScript, Java, SwiftFrameworks
Django, Flutter, Flask, Django REST FrameworkLibraries/APIs
Django ORM, REST APIs, SQLAlchemy, Google Sheets APITools
Android Studio, PyCharm, GitHub, BigQuery, NGINX, Google SheetsParadigms
Change Management, ManagementPlatforms
Ubuntu, Android, Firebase, Kubernetes, Google Cloud Platform (GCP), iOSStorage
PostgreSQLOther
Leadership, Team Leadership, Lean Project Management, Lean, Full-stack, Devtron, WebSockets, Process Management, Controlling, University Teaching, Project Management Office (PMO), Argo CD
Education
- Master's Degree in Business Administration2010 - 2015EM Strasbourg Business School - Strasbourg, France
