Design and implementation of a new cloud service

• Design of a new cloud service
• Requirements Engineering
• API Design (REST API, Kafka)
• Consulting on architecture, feasibility and effort estimation
• Implementation of a microservice architecture
• Implementation of a Spring Boot web service
• Development of REST APIs including business and persistence logic
• Kafka consumers and producers
• Various Excel upload/download scenarios
• Change Data Capture
• Cloud provisioning with IaC/Terraform
• Go-live with 30,000 users
• Operation, support and bug fixing for other services

Environment/tools: GitLab, JIRA, Confluence, IntelliJ, Spring Boot, Java, Docker, Terraform, AWS ECS, Postgres, Apache Kafka, SAP Datasphere, JUnit, Debezium, Apache POI, Hibernate, JPA, Testcontainers

• Regular maintenance and updates of Kubernetes cluster versions and the ecosystem (Helm, Prometheus, Velero)
• Patching and updating Ubuntu servers
• Updating services/frameworks (Spring, Angular, MongoDB, RabbitMQ, dependencies)

Environment/tools: Kubernetes, Ubuntu, Spring, Angular, MongoDB, Helm, Velero, Prometheus, Grafana

• Reducing cloud costs by over 70%
• Migrating services into the Kubernetes cluster
• Categorizing services by criticality and availability requirements
• Rightsizing services, Kubernetes nodes, EC2 instances, backups
• Increasing the share of spot instances
• Identifying and enabling appropriate saving plans
• Migrating single-tenancy to multi-tenancy in central services (MongoDB, RabbitMQ)
• Creating Kubernetes cron jobs for automated/on-demand shutdown and startup of developer services

Environment/tools: Kubernetes, AWS Auto-Scaling, AWS EBS, AWS S3, AWS EKS, MongoDB Atlas, RabbitMQ, Velero

• Measures to increase IT security and data privacy
• Implementation of Well-Architected principles
• Analysis of the service landscape
• Optimization of permissions management
• Establishment of penetration testing with OWASP
• Patching and secure code analysis
• Vulnerability scanning, audit logging
• Improvement of the password policy (randomization, MFA)
• Anonymization of personal data
• Implementation of encryption for data at rest, in transit, and in use
• Optimization and testing of backup and disaster recovery processes

Environment/Tools: AWS FTR, AWS CloudTrail, CloudWatch, OWASP, SonarQube, SSL, TLS 1.2, Java, Spring Boot, CodeShip

• Optimization of workflows around software development
• Introduction of Scrumban testing and release processes
• Development of a QA strategy
• Definition and establishment of unit, API, functional, regression, as well as load and stress tests
• Definition and implementation of SLAs
• Establishment of a support process using JIRA Service Desk
• Definition and outsourcing of the device provisioning process
• Setting up the CI/CD pipeline for app distribution (iOS, Android, wearables)

Environment/Tools: Jira Management, Jira Service Desk, Scrumban, Azure DevOps, F-Droid, Play Store, Apple Store, JUnit, TestLink

• Complete redesign of the prototype
• Team lead for staffing and onboarding (up to 8 FTE) including a unit in Ukraine and Serbia
• Introduction of the Scrum methodology
• Product Owner: product vision, strategy, refinement, and prioritization
• Development of a system architecture with microservices/event-driven architecture
• API design (REST API, AMQP)
• Implementation of an Angular frontend and a Spring Boot backend

Environment/Tools: Angular, HTML, CSS, Java, Spring Boot, RabbitMQ, Node.js, Node-RED, Docker, Ansible, nginx, AMQP, OAuth2, MongoDB, JSON, AsciiDocs, Xamarin, Windows 10 IoT

• Custom solution for customer management, production planning, and control of a plastic coater
• Regular refinement meetings with end customers
• Implementation of modules: customer management, inventory management, production planning, quality documentation
• Iterative approach using Scrum
• Integration of Siemens PLCs and barcode scanners

Environment/Tools: REST API, AngularJS, HTML, CSS, Spring Boot, Siemens S7, MongoDB