Timon R.
embedded linux, Java, Backend, BSI Standards
Experience
Administrator
Various clients
- Setup and maintenance of multiple web servers.
- Configuration of load balancing to distribute traffic across multiple servers.
- Implementation of HTTPS with Let's Encrypt certificates for secure data transmission.
- Setup of automated backups and recovery strategies.
- Optimization of server performance through caching (e.g., Redis, Memcached).
- Security measures such as SSH hardening, fail2ban, and regular security audits.
- Tools: Nginx / Caddy as web and proxy servers, Docker for containerizing applications, monitoring with Grafana.
Administrator
Various clients
- Setup of a wired and a Wi-Fi network based on TP-Link Omada.
- Planning and implementation of a redundant network architecture to ensure high availability.
- Setup of a Wi-Fi mesh network for seamless roaming between wireless repeaters.
- Configuration of VLANs to separate different network segments (e.g., staff, guests, IoT devices).
- Implementation of QoS rules to prioritize critical applications (e.g., VoIP, video conferences).
- Tools: Raspberry Pi with Ubuntu Server, TP-Link Omada Controller interface, routers, Wi-Fi devices, VLAN configuration via CLI/web interface, Wireshark for network analysis.
Backend Developer – Data Exchange Platform
Insurance Group
Generation of a KVNR: a service to create and securely store health insurance numbers for customers.
Development of a RESTful API for creating and managing KVNRs.
Implementation of secure storage and transmission of KVNR data in compliance with data protection regulations (e.g., GDPR).
Implementation of efficient validation and error handling to ensure the accuracy of the generated numbers.
Integration of a logging mechanism to track system operations and ensure auditability.
Creating an integration service: integrating various internal and external services into a unified data platform for data usage and further processing.
Design and implementation of a microservice architecture approach to integrate different data sources.
Development of an API gateway solution with Spring Boot to manage communication between internal and external services.
Implementation of mechanisms for synchronizing and harmonizing data from different systems to enable consistent data representation.
Implementation of error handling and retry mechanisms to improve the reliability of the integration service.
Implementation of a deletion concept for personal data in compliance with data protection regulations (e.g., GDPR).
Tools: Java + Spring Boot, Maven, IntelliJ, Postman, OpenAPI / Swagger, PostgreSQL, OPNsense.
Administrator
Various clients
- Setup of a smart home.
- Integration of various devices (e.g., lights, heating, security systems) into a seamless ZigBee mesh network.
- Implementation of automation rules (e.g., turn on lights on motion detection, adjust heating based on weather data).
- Ensuring data integrity and security through encrypted communication between devices.
- Optimized energy consumption analysis and control through intelligent device integration.
- Tools: Linux Raspberry Pi OS, Raspberry Pi as local server infrastructure, Home Assistant as central platform, Zigbee for wireless device communication, MQTT broker for seamless mesh communication.
Pen-Tester Training
- Planning and Scoping
- Information Gathering and Vulnerability Identification
- Attacks and Exploits
- Reporting and Communication
- Tools and Code Analysis
Backend Developer – Event Software
Software solution for accrediting meeting participants
- Defined interfaces and documented them using Swagger/OpenAPI for an API-first approach.
- Designed the backend architecture and implemented it.
- Tested and deployed the solution in the cloud.
- Tools: Java/Spring Boot (Microservices), Swagger, MinIO, MariaDB, GitHub including build pipelines, Kubernetes.
Backend Developer – Whistleblower Protection Software
lettly.de
- SaaS development for various clients.
- Implemented cryptographic methods, including BSI standard TR 02102-1.
- Implemented security and access concepts in backend systems.
- Set up a reporting unit according to the requirements of the Whistleblower Protection Act.
- Integrated Stripe as a payment provider.
- Tools: Java/Spring Boot (Microservices), Swagger, MongoDB, MinIO, MariaDB, GitHub including build pipelines, Kubernetes, Linux.
Backend Developer - Voting Software
ballotly.de
- SaaS development for various clients.
- Implemented cryptographic methods, including BSI standard TR 02102-1 and Common Criteria (CC).
- Implemented business logic according to election regulations.
- Created a sync concept for distributed architecture.
- Tools: Java/Spring Boot (Microservices), Swagger/OpenAPI, Redis, SSE, DDA MinIO, MariaDB, GitHub including build pipelines, Kubernetes, Linux.
Part-time Project
Automotive Supplier
- Created shipping labels on an industrial printer, including batch labels and labels for the outer packaging.
- Designed a server-client software architecture for scalability across multiple workstations.
- Developed interfaces to control industrial Zebra label printers.
- Designed and implemented bidirectional data synchronization between the labeling system and the MS SQL database.
- Provided support and maintenance for the software.
- Tools: IntelliJ, Java + JavaFX, MS SQL, Linux Raspberry Pi OS, Raspberry Pi.
Fullstack Developer - Plant Monitoring
Mechanical and Plant Engineering
- Further developed the new platform to support production in a distributed machine environment.
- Developed and deployed solutions based on different machine generations.
- Provided technology consulting for new equipment.
- Tools: Software architecture (EDA, DDD), Java/Spring Boot, MinIO, MySQL, MongoDB, MQTT, Mail Proxy & Bridges, C#.
Backend Developer - Documentation Tool
In-house development / various clients
- Service App as a documentation and reference tool for machines, projects, real estate & facility management.
- Template-based process documentation for consistent quality.
- Tools: Java/Spring Boot (Microservices), NodeJS, MongoDB, MinIO, MariaDB, GitLab, Docker & Docker Compose on Linux servers.
App Developer - Quality Assurance
Road construction and maintenance
- Networked App for quality control in road and asphalt construction.
- Design and implementation of the infrastructure and the Android App.
- Mathematical modeling of the business logic.
- Tools: Java, Android, BLE, SQLite, GitLab, Confluence.
Fullstack Developer - Process Management
Agriculture and forestry
- Further development of an in-house platform for process optimization and management in agricultural operations.
- Technology consulting.
- Tools: Software architecture (EDA; DDD), Java 8, Angular, NodeJS, Apache Cassandra, MariaDB.
Vocational training in application development
b.i.b. International College Bielefeld
Focus on fullstack and App development
Summary
Added value in digitalization and software development - from the first idea to the finished solution. "I enjoy finding fitting solutions together with my clients!" On the web, I'm at home in the backend - interfaces are my strength.
Languages
Education
B.I.B. International College Bielefeld
Vocational training in application development with a focus on full-stack and app development · Application Development · Bielefeld, Germany
Certifications & licenses
Pen-Tester
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