Hi! I'm Sergej

My work at RI is to advance fraud prevention by contributing to complex, distributed systems wich link and interpret transaction data.

Architecture and implementation of a NestJS microservice application

• Creating a microservices application with shared libs as a NestJS monorepo using Yarn workspaces
• Providing a local k8s setup with Skaffold to automatically rebuild Docker-images and sync changes
• Developing multibranch Jenkins pipeline in groovy and bash for the entire CI/CD
• Templating Kubernetes manifests with Helm to keep the deployment-code DRY
• Creating NestJS backends adhering to Domain Driven Design
• Connecting microservices through an Apollo GraphQL Federation facade-layer
• Implementing JWT authentication and ability-based authorization
• Persisting data in MongoDB using Mongoose as the ORM
• Creating an Angular Frontend with NGXS state-management
• Generating Angular services from the GraphQL schema
• Serving the frontend with Nginx
• Using Nginx as the ingress

Feature development for components of a big-data microservice application

• Creating new deployment setup with GitHub Actions to replace the Jenkins pipeline
• Adding a canary deployment feature on ingress level with Nginx
• Improving realtime user activity visualization using WebSockets though Apollo GraphQL
• Collaborating to improve of frontend-caching with Apollo and backend-caching with Redis
• Contributing to improvements regarding the microservice communication with Kafka and Protobuf
• Replacing InfluxDB with Prometheus for application-metrics by allowing the scraping of previously pushed metrics
• Contributing metric-visualizations to Grafana and Kibana
• Set up Application Performance Monitoring with Elastic APM
• Design and initiate gradual migration from ExpressJS to NestJS in the backend
• Maintain and extend the ExpressJS backend with MongoDB and Elasticsearch database layer and a GraphQL API layer
• Maintain and extend the Angular frontend wich is using NgRx

At WKC I contributed to a complex resource-planning application for an engineering service provider with sophisticated processes.
My domain was the implementation of the backend and frontend architecture for complex visualizations in extensive reports such as adding a gantt-like resource planning tool.

Extend the API-Platform (PHP) based backend stack

• Implement complex resolvers in the GraphQL API-layer
• Extend the Doctrine ORM-Layer which used a PostgreSQL database
• Model and implement entities with complex relationships and corresponding fixtures, migrations and required services

Extend GitlabCI and Docker Compose based deployment

• Implement test-setup for unit-tests with Jest
• Implement integration-tests with CodeceptJS
• Contribute to Docker Compose setup

Extend VueJS Frontend

• Introduce the functional library RamdaJS to handle data-transformations in the frontend effectively
• Implement a performance-optimized multi-level project-resource-planning calender by using a recycler list and functional components with optimized render functions

At Kuehne+Nagel I was responsible for the UI/UX alignment of the multiple frontend-stacks belonging to one large supply chain management application.

Leading the frontend and UX alignment of a supply chain management platform

• creating a shared component library and frontend development workflow.
• aligning the diverse stacks and responsible teams on the basis of the library integration.
• uniting the microservice application frontends, which included VueJS, React and even jQuery stacks on the basis of WebComponents.
• providing a living styleguide fo the integration of the library in the diverse architectures.
• fostering a common understanding of coding standards and current JS language features. To achieve the later I gave workshops on ES6+ and frontend related issues and tutored individual developers.

At Sinnerschrader Swipe my task was to contribute an innovative SPA frontend for the CMS based to the mcdonalds.ch website.

Create a Single-Page Google Maps App with embedded Multi-Page CMS content

• Contribute to the a Django and Wagtail-CMS backend and especially Webpack and a VueJS frontend with PostCSS.
• Creating a interactive restaurant map with filterable results and a responsive design as an SPA within within a traditional MPA
• Implementing dynamic hydration of CMS configured server-side-rendered restaurant-pages, modules and widgets with frontend-data
• Providing Frontend-multilingualism

At Brink & Martens I have worked on a PHP-based project for the Preview of the Webinterfaces of an OTTO-Group white-label shop system.

White-label shop system development: PHP-Backend and AngularJS Frontend

• Extend the project architecture by creating a configuration management backend and frontend to persist shop configurations and enables feature toggling
• Implement frontend features in the project, which used Grunt as it's build system, LESS as the Preprocessor and RequireJS as the module-loader

Design and Development of an AngularJS based component library

• Development of a pattern library with Gulp, SCSS, AngularJS and PHP
• Provision the frontend components in a structured and searchable component library
• Visualization of the components in the branding of the diverse shops.

Symfony based PHP-Project

• Contribute to the backend of a Symfony-based finance portal project.
• Contribute to the Twig-Frontend of said project.

Bachelor Of Arts In Computer Science And Economics

• Course of study: Bachelor of computer science and economics (grade: "good")
• Thesis: "Concept and prototype for automatic presence control with smart mobile devices - A context sensitive und adaptive multi-platform-solution" (grade: "very good")