AJAX Experts in Dusseldorf

• Contributed to the development of an advanced RAG AI Chat application that integrates multiple LLM models, enabling users to seamlessly switch between models based on specific tasks. This improved the user experience by providing tailored, efficient solutions for various use cases, such as event scheduling, booking systems, and complex task management.
• Participated in designing and implementing a robust backend architecture using Spring AI, enabling advanced AI-driven capabilities like intelligent task automation, language processing, and contextual recommendations. Leveraged Spring AI Tools and Advisors to enhance the performance and decision-making of the AI models.
• Collaborated on the integration of vector databases to support embeddings, enhancing the app's ability to understand user queries and perform actions based on complex, real-time data inputs.
• Contributed to the development of a seamless, user-friendly front-end interface using React with TypeScript support, ensuring a modern, responsive, and scalable user experience across platforms.
• Assisted in implementing state management with Redux RTK for efficient data flow and real-time updates, optimizing the overall user experience in dynamic scenarios such as scheduling and task management.
• Partnered with stakeholders to define feature requirements, helping ensure that the app could scale to meet evolving business needs and integrate with other systems like calendar and email services. Worked alongside cross-functional teams, including data scientists and UI/UX designers, to fine-tune AI models and ensure alignment with project goals.
• Contributed to ensuring end-to-end system performance, security, and compliance by helping integrate authentication mechanisms, role-based access control, and secure communication protocols in both backend and frontend layers.

Technology Stack and Key Contributions:

• Java / Spring Boot / Spring AI: Developed backend services leveraging Spring AI for intelligent responses, task automation, and complex workflows.
• React / TypeScript: Built intuitive user interfaces with React and TypeScript, ensuring a smooth and scalable frontend.
• Redux RTK: Managed application state with Redux RTK for optimized state management, enabling dynamic, real-time data updates.
• Vector Databases: Integrated vector databases (pgVector) for embedding support, improving AI model performance in handling complex queries.
• PostgreSQL / Redis: Managed persistent and temporary data with relational and in-memory data stores, ensuring data integrity and speed.
• Kafka: Utilized Apache Kafka for event-driven communication and seamless integration between microservices.
• Spring Security: Ensured the security of backend services with robust authentication and authorization mechanisms.
• CI/CD & DevOps: Integrated continuous integration and deployment pipelines to ensure rapid and secure deployment of features and updates.

• Development and maintenance of database-driven applications for managing supplier and food contracts, with extensive use of Oracle PL/SQL for complex business logic and data processing
• Optimization of PL/SQL procedures, functions, and triggers to ensure the performance and scalability of Oracle database solutions
• Ensuring compliance with best practices in PL/SQL development and implementing standards for code quality and data integrity
• Close collaboration with backend and frontend teams to ensure smooth integration between the Oracle database, C#-based APIs, and Azure cloud services

• Design and implementation of an OCI-based DWH and ETL system to replace legacy mainframe applications
• Development of a database optimization strategy and planning the rapid conversion of JCL and COBOL routines to PL/SQL with the help of AI
• Development of an Oracle Apex-based app for internal administrative processes in the public sector (office equipment, employee training)
• Implementation of PL/SQL workflows for approval processes and creation of a responsive mobile version with JavaScript and CSS
• Use of Azure DevOps for backlog and documentation, as well as Git for version control
• Development of REST interfaces for CRM systems
• Replacement and reprogramming of Oracle Forms screens with Oracle Apex and upgrading to the latest Apex versions
• Design of a Git branching strategy and conducting code reviews
• Maintenance and further development of an EDI-based data exchange system based on Oracle Advanced Queuing for the public sector in Austria
• Data analysis and creation of charts in the Oracle Apex frontend; installation of standalone ORDS and Apex 23.1
• Agile working according to the Spotify Model; development of complex Apex screens with the support of Oracle JET
• New development and customization of existing PL/SQL packages, workarounds for database version differences and query optimization
• Development of Apex applications for broker pools to manage and optimize Oracle databases in the banking sector, including SSO-based authorization systems with OAuth2 and Keycloak
• Development of extensive Oracle Apex applications for BI and data mining modernization projects, as well as development of manual and automated projection methods in the frontend
• Implementation of data warehousing projects in the banking sector and use of Scrum and Kanban in team-oriented projects

• The Forecasting Cost Tool (PCCT) imports data from CSV files via SSIS and processes modules for administration, user management, train operations, and fleet operations.
• Conducted requirements analysis and effort estimation.
• Designed the database and developed web pages.
• Tested the application.

• Architecting and developing SaaS platform for graphical definition and execution of pandas data processing pipelines
• Developed POlyglott, an open-source Python CLI tool for translation workflow management featuring PO file parsing, quality linting with glossary enforcement, and DeepL API integration for machine translation
• Developed web application for material compliance management (EU REACH) using Django and modern web technologies
• Built automated infrastructure platform using Proxmox, Terraform, and Ansible — VM provisioning, configuration management, internal DNS, and fleet-wide security hardening across multiple subnets

• Setting up and enhancing an international subscription management system

• Migrating and decommissioning a Hybris-SAP system and integrating Zuora

• Implementing numerous interfaces to various systems (external and internal)

• Setting up and improving monitoring with Grafana, Prometheus, and Databricks

• Introducing logging with Loki

• Implementing business requirements using jQuery, Thymeleaf, Spring Boot, Java, Go, and Python

• Adjusting and extending the GitLab CI pipelines

• Setting up and extending infrastructure as code with Terraform and ArgoCD on AWS

• Setting up and running E2E and performance tests

• Expanding the Databricks business intelligence solution to provide various KPIs

• Responsibilities: Architecture, DevOps, development, unit tests, coaching employees and apprentices, E2E, smoke, and integration tests, agile methods consulting (Kanban, Scrum)

• Technologies and methods: Java, Go, Kotlin, Node.js, Spring Boot, SOAP/REST, Quarkus, Thymeleaf, Vaadin, Slack, Jira, Confluence, IntelliJ, GitLab, SQS, Kafka, AWS, Kubernetes, Terraform, Maven, Gradle, GitLab CI, Databricks