Client Projects

Development of a B2B platform in the wealth and asset management sector.

The complex data structures were provided via GraphQL. The data itself came from various sources, requiring complex and traceable workflows to ensure data consistency.

Temporal was used for this purpose, while gRPC and Protobuf were used for service-to-service communication.

Tech Stack: GraphQL, gRPC, Protobuf, TypeScript, Drizzle, Go, PostgreSQL, Temporal

Weißaufschwarz develops software that facilitates the daily work of other web and digital agencies in areas such as software development, deployment, and maintenance.

The challenge here was implementing the backend with integration to various systems, with special consideration given to access rights in a greenfield environment.

Tech Stack: TypeScript, Drizzle, PURISTA, MySQL, REST API/Webhooks

Nomo is a FinTech company specializing in clients from Kuwait and the United Kingdom. It offers its customers an app that provides a wide range of financial services.

Nomo relies on a modern AWS cloud stack, with most functionalities implemented as AWS Lambda functions.

I significantly contributed to the backend development of two key areas.

First, the central integration of the system with the credit card provider, enabling users to issue and manage cards for their bank accounts.

Second, various financial services were offered to users, which included the integration with a stock marketplace platform.

The resulting complex business logic was implemented using AWS Lambda functions and Temporal.

Tech Stack: TypeScript, AWS Lambda, AWS EventBridge, AWS DynamoDB, Temporal, REST API

The client provides their own products for collecting and analyzing data from machines and equipment.

The existing user interface based on Riot.js was to be completely migrated to the Vue.js framework. Existing functions needed to be re-implemented, extended, and adapted to new requirements. The frontend's functionality ranged from simple administrative interfaces to customizable, highly dynamic dashboards.

A particular challenge was handling very large, rapidly changing sensor data in the browser.

Other requirements included customer-specific themes, access rights management, and responsive design to ensure usability on mobile devices.

Tech Stack: Vue, TypeScript, REST API, Websockets

Yunar developed its own loyalty program, which calculates corresponding point balances based on the user's bank transactions.

The functionality was distributed across multiple microservices running in a Kubernetes cluster, secured through various security mechanisms. The microservices used MS-SQL for data persistence and communicated both internally and externally via REST API interfaces.

Unit and integration tests were employed using tools such as Mocha, SonarQube, and Docker to ensure the correct functionality of the microservices. These tools were also used during implementation to locally simulate dependencies.

Tech Stack: TypeScript, MS-SQL, Azure, REST API, EventStore, CQRS

Modifications to the existing PHP backend for synchronizing map updates for Daimler's in-car navigation systems to align with the current NTG7 format.

Tech Stack: PHP

Implementation of microservices in TypeScript within a cloud-based infrastructure for generating various documents and output formats.

RabbitMQ was used for communication between individual microservices, and MSSQL served as the data storage. The main challenge was handling millions of document requests with limited resources. Document generation requests were batched and sent to an external service via REST API. The external service could only process a limited number of requests simultaneously, and processing was very time-consuming, requiring appropriate queuing mechanisms that functioned reliably across multiple service instances (parallel processing).

Additionally, generated documents had to be further processed and delivered to several other external services.

Unfortunately, the project had to be terminated prematurely by the client due to the European Court of Justice ruling on the German car toll.

Tech Stack: TypeScript, RabbitMQ, MS-SQL

Implementation of the core functions of the entire system, from design and development to automated testing.

For the backend development, Node.js-based microservices were implemented within a Microsoft Azure cloud infrastructure. Key elements of the project included:

The integration with external loyalty providers via API and web scraping for data exchange, and providing data via REST API for mobile clients. Additionally, the entire architecture was based on CQRS/event-driven design, and instead of a traditional database, EventStore was used as the data storage solution.

Since this was a financial industry project dealing with sensitive user data, special emphasis was placed on security, auditing, and testing.

The project involved guiding and shaping the entire process from the initial idea to the publicly available product.

Tech Stack: TypeScript, MS-SQL, Azure, REST API, EventStore, CQRS

Development of software for testing toll terminals built by Krauth Technology for Toll Collect.

This project specifically focused on the communication between individual components within the terminal (printer, screen, card payment system, etc.) via D-Bus, and communication with the backend (Toll Collect) via SNMP, which played a crucial role in fulfilling the evidence requirements for Toll Collect and regulatory authorities. Besides the actual implementation of the test tool, creating test procedures and conducting tests directly on the terminals was also a key part of the work. This was all done in close collaboration with project management, various developers, and development companies.

As the project progressed, the scope was extended to cover the entire terminal system, including tests of individual components as well as the overall system. Additionally, the responsibilities ranged from software testing, troubleshooting, and error analysis to assisting with the integration of individual terminals into the Toll Collect system.

Tech Stack: TypeScript, SNMP

This project focused on documentation, traceability (related to ISO certification, etc.), and real-time location information in the logistics and transportation sector. The entire frontend was designed for browser-based operation, ensuring that input forms, dashboards, analytics, and overviews were accessible on all common input devices by implementing them in JavaScript, HTML, and CSS.

Tech Stack: TypeScript

This project focused on meeting performance requirements in terms of availability, scalability, and performance to ensure future competitiveness.

User interfaces for administration, settings, as well as graphical representation in various dashboards, and data preparation for ease of understanding and clarity were implemented in JavaScript, HTML, and CSS (LESS).

Tech Stack: TypeScript, MySQL, Photoshop

An internationally-oriented portal realized with PHP & MySQL, focused on several main features:

• CMS capabilities (content management)
• Targeted advertising based on geo-location information
• Booking/billing functions
• Analytics, user tracking, SEO optimization, and intelligent search/content offerings

Corresponding user interfaces for management, analytics, and dashboards were designed and implemented for use in the browser.

Tech Stack: TypeScript, MySQL, Photoshop

Various smaller projects, primarily focused on PHP. This often involved close collaboration with, for example, web designers, sales/marketing teams, management, developers, and end users.

Tech Stack: PHP, JavaScript, TypeScript, MySQL, Photoshop