12grapes GmbH is the company behind the app Bunch, an AI coach that makes it easy to learn and grow your
leadership skills with bite-sized daily tips.
I joined Bunch in August 2020 to help develop new features and reduce the technical depth to make the app
more performant, maintainable, and testable at the same time. To achieve this, I've built a backend with a
REST API and outsourced some of the app's business logic. Furthermore, I introduced Functional Reactive
Programming in an MVVM setup.
The app enables selected users to upload single or multiple photos combined with text to a public feed,
which automatically deletes the content after two days. In addition, the app allows one user to stream live
videos simultaneously, which then appear in the feed. Viewers of the stream can send emoji reactions
which then move across the screen for all participants to see.
Besides photos, selected users can also post products for sale in the feed which are paid for
via Apple Pay and can even be purchased by unregistered users.
A special feature of the app is that all actions are visible to other users in real-time.
For example, if a user writes a text, other users can watch the author writing it even before it is published.
Features
Live video streaming
Live updates through WebSocket
Sign in with Apple
(Multiple) Image posting
Text posting
Photo cropping
Commenting
Mentioning users in comments
Technologies used
WebSocket
WebRTC
Mediasoup
RxSwift
Fastlane
SnapKit
Push Notifications
Apple Pay
Stripe
MVVM
Unit tests
Sparkasse
HaspaJoker App
In December 2019 I joined the app team of Sparkasse's agency S-Markt & Mehrwert GmbH to support them on one of their projects, a white label customer loyalty app they're offering to their partners, one of which is Hamburger Sparkasse's app HaspaJoker.
Through the app, customers get special offers and discounts from local partners, can book travel/concert tickets and benefit from a variety of other perks and services. The agile scrum team consisted of 5 iOS, 4 Android as well as 4 backend developers and was working predominantly remotely. Some of the work I did included refactoring and consolidating the codebase to be testable, introducing Screenshot tests, automating tasks, and implementing new features.
Spielworks hired me to kick-start their product "Wombat" for iOS. For this greenfield project, I did both the architecture and the implementation of the beta version and later hired another developer who eventually took the project over.
The app is the first EOS wallet built for everyday use and simplifies the creation of EOS accounts through a three-step onboarding process. It automatically encrypts and stores the private key in the cloud and makes sending/receiving EOS tokens a breeze. One of the core features of the app is the DAPP Browser that acts as a proxy between DAPP and the EOS account and provides a streamlined user-interface to sign transactions.
Together with another developer I’ve built the fitness video portal “My Fitness Video” for Fitness First. The project was set up with high scalability and security in mind and was built entirely with various components of Amazon Web Services (AWS). It consists of three main parts. Firstly the backend, where one of the bigger challenges was, to implement the whole payment and subscription process. Secondly the web app, a server-side rendered vue.js single page application, and thirdly the content and customer management system for administrators.
After having helped out Vantik as a freelancer end of 2017, I joined full-time in 2018 to build up the entire frontend stack and team. Vantik is an investment-based retirement savings product (private pension). Since Vantik is a banking product, the highest priority in all layers of the stack was security and compliance with the German federal financial supervisory authority (BaFin).
Together with a team of developers put together by functionalaesthetics, I was working on the iOS swift app (universal - iPhone & iPad) for Boston Consulting Group’s client smile.direct, a Swiss insurance company. The app was designed to help families planning their everyday life. The main part of the app is an elaborate calendar, heavily optimized for easy user experience on both the iPad and iPhone. Furthermore, family members have profiles and can easily communicate through private messages.
Features (excerpt)
Universal (iPhone & iPad) App
Calendar component
Push Notifications
Create & edit events
Comments
Animated onboarding
Create & edit task lists
Import calendars
Sharing
User registration & login
Reset & change password
Family setup
Private messages
Change app theme
Technologies used
Swift
UIKit
Fastlane
RxSwift
MVVM
Reactive programming
Alamofire
AlamofireImage
SwiftLint
SnapKit
Firebase
BuddyBuild
Core Text
Core Telephony
Quartz Core
AVFoundation
Core Media
Core Video
Wine in Black
Wine in Black App
Together with another app developer I’ve built the native iOS swift (universal - iPhone & iPad) app for Wine in Black, a wine e-commerce company. Due to the fact that Wine in Black is a curated shop with a limited, constantly changing assortment, the app stores all active products on the device and synchs with the server on startup so that all interactions with products such as browse, search or filter are instant and do not require a network connection.
Besides working on the iOS app, another part of the job was building a new REST API. This was necessary because the existing shop system was being replaced during the project.
For universeiscool, I built the social image sharing app FOYER. It enables the user to combine text and photos into a story and a layout algorithm takes care that stories look unique and good on any device. An integrated image editor provides an easy way to get the most out of the pictures and social features such as share, like and comment make sure that stories get the attention they deserve. The social feed channelizes the stories created or shared by followed users and the discover section in the app exposes stories of users from outside the user’s network.
