Daniel Nelle

I support my customers in the areas of databases, DevOps, cloud, security, web and API infrastructure, network + firewalls and Linux.

Collaborate on various OpenSource projects as a programmer or consultant.

Specifics:

Besides the daily tasks as an IT specialist, which are described in the further course of my profile, I would like to mention the following things:

• Design and programming of an Oracle database monitoring software with Go (golang), APEX and PL/SQL.
• Database monitoring with elasticsearch, logstash, filebeat and kibana. As well as several publications about this topic.
• Security Log Analytics: BigData with log data or Data Science with log data from dozens of servers and log sources.

Technologies:

• Oracle
• RMAN
• SQL Tuning
• APEX
• Go (golang)
• PL/SQL
• elasticsearch
• logstash
• filebeat
• kibana
• OSSec
• wazuh
• KaliLinux
• SecurityOnion
• firewalld
• iptables
• OpenSwan
• Apache
• SELinux
• Fail2Ban
• syslogd
• CentOS
• RedHat
• Oracle Enterprise Linux

As Team Lead Platform at TeamViewer, I lead an organization of 13 - 21 engineers across three specialized teams: Core Backend Development (ranging from Senior to Senior Principal Engineers), Platform Operations for core products, and the central Platform Engineering Team. Combining strategic management with technical leadership, my mission is to evolve our infrastructure landscape into an intuitive, flexible Platform Engineering ecosystem. My key guidelines are self-service, strong architectural standards, continuous innovation, and fun to build an awesome platform.

Platform Strategy & Engineering

• Evolution to Modern Platform Engineering
• Leading the strategic transformation from traditional Platform Operations into a pure Platform Engineering domain focused on developer enablement.
• Building self-service "Golden Paths" and intuitive building blocks that empower engineering and operation teams to compose infrastructure.
• Establishing Kubernetes as the central platform foundation, utilizing operators to manage cloud resources declaratively across Azure, Anexia, GCP and AWS.
• Agentic Platform & AI Integration
• Integration of SRE AI agents directly into our platform.
• Driving the shift toward agentic platform coding, code reviews and infrastructure management.
• Prioritizing full coverage of Agent instructions, empowering AI Agents of Development teams to fully understand the platform.
• Governance, Quality & Compliance
• Business owner of our platform and core services on-call team.
• Responsible for the Blameless Post Mortem culture, root cause analysis and the prioritization of post incident tasks accross departments.
• Technical lead for the implementation and architecture of our FedRAMP Class C (Moderate), FIPS, ISO-27001 compliant infrastructure.
• Established quality gates and architectural reviews during the early design phases of services to maintain consistency and long-term reliability.
• Initiated and introduced standardized service chassis frameworks to enforce architectural guidelines and standardize service telemetry and operational behavior.

Platform Security

• Seamless DevSecOps Integration:
  Embedding security controls directly into standard engineering workflows and delivery pipelines to make security the standard approach.
• Multi-Layer Defense in Depth ("Two-Mistake Rule")
  Architecting resilient, multi-layer policy enforcement across code repositories, Kubernetes clusters, and cloud providers, ensuring a single mistake never leads to an exposure.
• Clear Ownership & Remediation Processes
  Designing clear processes to immediately route security findings to Directly Responsible Individuals.

Management & Leadership

• Disciplinary responsibility and leadership for 13 - 21 direct reports across three engineering teams.
• Active mentorship and knowledge development for engineers at all levels, including Senior, Staff, Principal, and Senior Principal levels.
• Executing performance evaluations, structured feedback talks, and talent assessments using 9-box matrix frameworks.
• Managing salary reviews, merit planning, and compensation alignments.
• Responsible for headcount planning and recruting.
• Overseeing comprehensive budget planning for platform teams as well as TeamViewer's core global infrastructure.

Techstack:

• Kubernetes (AKS)
• Crossplane
• Terraform
• Kubernetes Operators
• ArgoCD
• GitLab
• OpenCode
• HolmesGPT
• AI Agents
• SRE AI
• FedRAMP
• Istio
• Azure
• Anexia
• GCP
• AWS

As Team Lead DevOps / SRE at GoStudent, I was responsible for the cloud infrastructure of GoStudent Services, the Data Platform and the Internal Development Platform (IDP). I reported directly to the VP Engineering, which gave me a much wider scope of responsibility than is usually expected from a Team Lead DevOps. I led a team of 3-5 people, balancing my time roughly 30% in management and 70% doing hands-on technical work.

Objectives and Initiatives

• Cloud migration from Hetzner to AWS
• Architecting and designing of the cloud infrastructure from scratch
• Maintaining existing infrastructure while preparing the migration
• Zero downtime switch to the new AWS infrastructure
• Self-Service
• We transitioned from two deployments per week to avg. one deployment per hour.
• As a central DevOps / SRE team with a comparatively low headcount, we interpreted the DevOps role as a development platform provider and offered developers the possibility to deploy, manage and debug their services independently, even in production.
• "You built it, you run it!" By intensively involving developers in the production operation of their services, we were able to drastically improve the stability of our services within a few months. It led to the consideration of upgrade paths already during the development of the services, thus minimising breaking changes - minimising deployment risks.
• Internal Development Platform (IDP)
• Our Internal Development Platform was part of our self-service philosophy. It was about integrating technologies and systems into the platform so that they could be used by developers without further DevOps activity. Explained with a practical example: If a service needed an S3 bucket, the service owner (developer) only had to define it in the service configuration. The creation of the bucket, the permissions, the backup, etc. was handled fully automatically in the background.

Techstack:

• AWS
• Kubernetes (EKS)
• Terraform
• ArgoCD
• Argo Workflows
• GitLab
• RedShift
• Airflow
• Scylla DB (Cassandra)
• RDS
• dynamoDB
• NATS

I was acting as technical leader / Staff Engineer of the cloud platform, working closely with stakeholders and shaping the future platform. I was responsible for the design, implementation, operation and monitoring of the Uniserv Cloud infrastructure. This included the high available Uniserv SaaS products, the cloud infrastructure itself and the DevOps tool stack.

Environment

• Cloud: AWS
• Linux: Ubuntu, Amazon Linux, Debian, SuSE
• Databases: MySQL, MariaDB, PostgreSQL, Aurora (MySQL, PostgreSQL), dynamoDB

Cloud

• Setup, maintenance and monitoring of cloud environments in AWS.
• Automating AWS Infrastructure with Terraform.
• Automating the gitLab environment for CD purposes.
• Development of continuous deployment (CD) concepts (GitOps), infrastructure and pipelines.
• Setting up and running Docker containers in AWS ECS and AWS Fargate.
• Migrating Docker containers from AWS ECS to Kubernetes Clusters (EKS).
• Provisioning of server images (AMI) with Packer and Ansible.
• Backup and disaster recovery conception of the cloud services.
• Management of application logs with AWS CloudWatch, Kinesis Firehose and Splunk.
• Regular exchange of concepts, experiences and commonalities with the Uniserv Azure DevOps team.

Projects

• Conception of a central AWS network environment. This enabled a better overview of security as well as sharing of network resources e.g. NAT gateway or VPN connections.
• Planning, automation and operation of a Continuous Integration (CI) environment consisting of Jenkins, Artifactory and SonarQube.
• Automating the deployment, operation, and disaster recovery of cloud native applications (Java Spring Boot) and classic applications in the cloud.
• Building and migrating Splunk environment to AWS, streaming cloud watch logs to Splunk.

Kubernetes

• Construction and conception of Kubernetes clusters in AWS (EKS).
• Conceptual design and implementation of network infrastructure and security concepts around Kubernetes.
• Integration of Kubernetes clusters in AWS, interaction with AWS and on-premise services.
• Volume, secrets and namespace management (RBAC).
• Monitoring (prometheus) and log shipping (elasticsearch).
• Supporting Development in integrating their test environments into Kubernetes.

Security

• Hardening Linux servers with direct and indirect Internet access.
• Planning and managing AWS Security Groups and NACLs with Terraform.
• Construction and monitoring of site-to-site VPNs between AWS and on-premise.
• Log Analytics, security relevant information analysis from hundreds of millions of log records.
• Establish automation to monitor security configurations.

Others

• Technical leadership of the DevOps team as an Infrastructure Architect.
• Shaping future vision of DevOps landscape.
• Maintenance of cloud and on-premise databases.
• Support of Development in all database issues.
• Working in an agile team, based on Scrum.

Techstack:

• Cloud
• AWS
• Docker
• Kubernetes
• Terraform
• Packer
• Ansible
• Python
• Git
• GitLab
• Jenkins
• Artifactory
• SonarQube
• Apache
• Nginx
• Splunk
• Shell Script

Responsible for maintenance and servicing of customer databases. Troubleshooting, database and SQL tuning. Execution of various installation and migration projects, infrastructure topics, and much more.
IT security topics, in particular database and web server hardening as well as security monitoring.

Environments

• UNIX: Sun Solaris from version 9, IBM AIX from version 7
• Linux: RedHat, SuSE, Oracle Enterprise Linux from version 4
• Windows Server from 2003
• Databases: Oracle 10g, 11g, 12c, 18c, MySQL

Cloud

• Setup and maintenance of cloud environments (Oracle and AWS).
• Creating and managing Docker images.
• "Orchestrating" Docker containers and instances.
• Configuration management with Ansible
• Backup to Cloud.
• Complete disaster recovery scenarios of the on-premise infrastructure with cloud technologies.

Projects

Project management and implementation of customer-specific database solutions, primarily in the area of high availability (Data Guard, RAC). Execution of database and SQL tuning projects. Maintenance of Oracle Database Appliances (ODA) Drafting, software design, and programming of a monitoring software for Oracle databases. Leading workshops on Oracle topics.

Activities in the area of database backup

• Development of backup concepts with RMAN
• Creating shell scripts for backing up Oracle databases
• Backing up RAC and DataGuard environments
• Monitoring and troubleshooting of RMAN backups
• Cloning databases with RMAN
• Cloning Pluggable Database (PDB)
• Exporting and importing databases with exp/imp as well as Datapump

Database availability and high availability

RAC databases

Installation, configuration, and maintenance, restoring databases after data loss optionally as a single-instance or RAC database, troubleshooting during and after an outage with root cause analysis, reinstallation of a RAC node and subsequent reintegration into the RAC without downtime.

DataGuard environments

Troubleshooting in case of failure of synchronization between the participating databases, running through various switch-over and fail-over scenarios, backing up the standby database instead of the primary, setup of a DataGuard environment between a Windows and a Linux server, scripting a manual DataGuard environment with Oracle Standard Edition and rsync, upgrade and migration of Grid Infrastructure and ASM, migration and replication with Oracle Golden Gate.

Security

• Hardening of Linux servers with direct and indirect internet access.
• Firewall concepts and configurations.
• Setup, monitoring, and maintenance of VPN connections (OpenVPN and IPSec).
• Administration of SELinux, assignment of filesystem flags, and granular configuration of access permissions.
• Apache mod_security configuration and troubleshooting.
• Log Analytics, security-relevant information evaluation from several hundred million log entries.
• Checking applications for security vulnerabilities.

Miscellaneous

• Conceptualization and implementation of partitioned tables in an existing multi-terabyte database (with minimal downtime).
• Administration of Oracle VM.
• Support during the commissioning of 10 Oracle Database Appliances (ODA), RAC + DataGuard.
• Planning and implementation of an Apache web cluster with HAProxy as load balancer.
• Migration of several RAC-DataGuard configurations with minimal downtime.

Technologies:

• Oracle
• ODA
• RAC
• DataGuard
• SQL Tuning
• RMAN
• Oracle Database Appliance
• Cloud
• Docker
• Ansible
• Apache
• HAproxy
• Oracle Secure Backup
• Oracle Cloud
• APEX
• PL/SQL
• SELinux
• LogAnalytics
• Shell Script

Responsible for the maintenance and smooth operation of the databases at ESPRIT. A particular challenge was a database availability requirement of 100% during the monthly "order week" when the new fashion collection was presented.

Highlights:

In addition to general activities as a database specialist, the following projects stood out:

• Maintenance and further development of the database monitoring system
• Fully automated database management tasks

Technologies:

• Oracle
• RAC
• DataGuard
• RMAN
• SQL Tuning
• APEX
• PL/SQL
• Shell Script

Responsible for the maintenance and smooth operation of the databases at mentasys and pangora (merger of mentasys and pangora).

Highlights:

The very specific requirements for the databases were a special challenge here. On the one hand, huge amounts of data were stored in the databases; on the other hand, these were also permanently and completely read.

• Performance troubleshooting as a daily task.
• SQL tuning
• Coordination with the development team on software design and data modeling.
• Backup and recovery concept design.
• Upgrades and migrations with minimal downtime.
• Manually scripted standby databases, replications

Technologies:

• Oracle
• MS SQL Server
• SQL Server Replication
• Oracle Manual Standby
• SQL Tuning
• PL/SQL
• Shell Script

Responsible for the maintenance and smooth operation of the databases at ETAS. One of the main focus areas was SQL tuning. One of the databases had grown historically and was due to be replaced soon. For the transition period, data from both databases was required, which proved to be a nice challenge for the SQL developer.

Conception and implementation of an RMAN backup concept to replace manual scripts.

Technologies:

• Oracle
• RMAN
• SQL Tuning
• PL/SQL
• Oracle Ultra Search
• Shell Script

Installation and configuration of Oracle databases. Creating and monitoring RMAN backups. Evaluation of new features in Oracle 10g, e.g., Flashback and Datapump.

Configuration of an Oracle DataGuard.

Technologies:

• Oracle
• RMAN
• DataGuard
• Partitioning

Development of an in-house CMS with PHP and MySQL (LAMP).
Maintenance of the Linux and Windows servers.

Technologies:

• SLES
• Exchange Server
• Active Directory
• PHP
• MySQL