Robert is available for hire
Hire RobertRobert Muller
Verified Expert in Engineering
DevOps Engineer and Software Developer
Bucharest, Romania
Toptal member since January 14, 2019
Bio
Robert is a DevOps engineer with in-depth and practical experience in a wide range of technologies. He's also a great listener and chock full of information, which he gladly shares with his team as needed. Cloud-agnostic, automation-oriented, and passionate about coding, Robert joined Toptal to find the most complex and challenging projects out there.
Portfolio
Ontologix LLC
Cloud Architecture, Kubernetes, Terraform, API Design, Microservices...
JohnSnowLabs
Cloud Architecture, Kubernetes, Terraform, API Design, Microservices...
Pfizer - PGS Operations Insights
Amazon Web Services (AWS), Kubernetes, GitHub, GitHub Actions, Terraform...
Experience
- Linux - 12 years
- Jenkins - 10 years
- Python - 7 years
- DevOps - 6 years
- Docker - 5 years
- Amazon Web Services (AWS) - 5 years
- Kubernetes - 4 years
- Ansible - 4 years
Preferred Environment
Python, Linux, Amazon Web Services (AWS)
The most amazing...
...project I've done is a migration of an application containing a huge number of microservices from a traditional data center to an AWS cloud with no downtime.
Work Experience
Cloud Infrastructure Engineer
2026 - PRESENT
Ontologix LLC
- Implemented GitOps delivery with Flux and Kustomize using a base/overlays layout, with GitHub Actions handling build, test, and image publishing before Flux reconciled the change into the target cluster.
- Provisioned and managed the entire infrastructure as code with Terraform, using remote state, reusable modules, and separate workspaces per environment for repeatable rebuilds.
- Secured the container supply chain end to end: images signed with Cosign, vulnerability and SBOM scanning with Trivy in CI, and admission-time verification so only signed, scanned images could be deployed.
- Designed the private networking layer on Nebula, running the certificate authority and host certificates that enforce mutual TLS between all nodes, so every service-to-service call is authenticated and encrypted over the overlay mesh.
Technologies: Cloud Architecture, Kubernetes, Terraform, API Design, Microservices, Amazon Web Services (AWS), Google Cloud Platform (GCP), Kustomize, Helm, Kyverno, Grafana, Prometheus, Flux, GitHub Actions
DevOps Engineer
2024 - 2026
JohnSnowLabs
- Maintained the product's Helm chart and ensured compatibility across multiple Kubernetes distributions—k3s, EKS, and AKS—handling the differences in ingress, storage classes, and load balancer behavior between them.
- Built an audit logging solution based on Elasticsearch and Kibana, shipping application and access logs into indexed storage with dashboards for review and retention policies for lifecycle management.
- Wrote and maintained a large set of Jenkins jobs and pipelines covering build, test, packaging, and release of the product, including automated image builds and artifact publishing.
- Supported fully airgapped installations of the products, including private registry mirroring and offline installation procedures for customer environments.
- Published and maintained cloud marketplace listings, packaging the product for distribution and automating the build and submission steps for each release.
Technologies: Cloud Architecture, Kubernetes, Terraform, API Design, Microservices, Amazon Web Services (AWS), Azure, Packer, K3s, Helm
DevOps Developer
2024 - 2024
Pfizer - PGS Operations Insights
- Improved the process of building Docker images containing LLMs.
- Improved GitHub Actions for better reliability and fewer failures.
- Developed new GitHub Actions to improve deployment processes and acceptance environment handling.
Technologies: Amazon Web Services (AWS), Kubernetes, GitHub, GitHub Actions, Terraform, Large Language Models (LLMs), Python 3, Honeycomb, Elasticsearch, Redis, OpenTelemetry, Amazon RDS, Amazon CloudWatch, HIPAA Compliance, Amazon Linux, Amazon DynamoDB, Kubernetes HorizontalPodAutoscaler (HPA), Role-based Access Control (RBAC), Cloud Architecture
DevOps Engineer
2023 - 2024
Blackfish Media LLC
- Migrated the client's entire technical solution from LiquidWeb virtual machines to AWS EKS.
- Deployed the entire infrastructure through IaaC (Terraform).
- Created CI/CD pipelines in Bitbucket Pipelines for deploying code through different stages.
Technologies: DevOps, CI/CD Pipelines, DevOps Engineer, Jenkins, Staging, Bitbucket, Terraform, Amazon EKS, Cloudflare, OAuth 2, SendGrid, Bash, Amazon RDS, Amazon CloudWatch, Amazon Linux, Amazon DynamoDB, Kubernetes HorizontalPodAutoscaler (HPA), Role-based Access Control (RBAC), Cloud Architecture
Cloud Engineer
2018 - 2023
Twinner GmbH
- Built the Azure infrastructure, deployed the resources, and implemented the security. The infrastructure was wholly created using infrastructure as code (ARM templates).
- Wrote Jenkins jobs and pipelines for the automation of several processes. Jenkins was configured in a scripted way, and all jobs were created using Jenkins Configuration as Code and Jenkins DSL.
- Created several Bitbucket pipelines for automatic Docker builds and pushed them to ACR registries.
- Implemented a complex monitoring solution using Grafana, Prometheus, Loki, Promtail, InfluxDB, and Telegraf.
- Managed complex worldwide infrastructure using Salt configuration management. Several Salt state files were created for this, which included many Powershell scripts to be run locally on remote servers.
- Migrated the entire infrastructure from Azure app services and functions to AKS. Multiple Kubernetes clusters were managed using Helm charts and included tools like NGiNX-controller, cert-manager, KEDA, Linkerd, Snyk, Velero, and more.
Technologies: Grafana, Prometheus, Vault, GitLab, Jenkins, Windows PowerShell, Azure, SaltStack, Telegraf, InfluxDB, ARM, Python 3, Azure Kubernetes Service (AKS), Helm, NGINX, Bitbucket, Jira, Confluence, Docker, Seq, Linkerd, Velero, Snyk, Kubernetes Event-driven Autoscaler (KEDA), Loki, Jenkins Pipeline, Jenkins Job DSL, Bash Script, Python, Azure DevOps, CI/CD Pipelines, Infrastructure as Code (IaC), Cloud Infrastructure, Configuration Management, Site Reliability Engineering (SRE), Containers, IT Systems Engineering, Continuous Delivery (CD), Continuous Integration (CI), Serverless Architecture, Microservices, API/Services Architecture, Event-driven Architecture, OpenAPI, C#, Argo CD, GitOps, Unix, Monitoring, Performance Analysis, Containerization, DevOps Engineer, Staging, Ubuntu, Elasticsearch, Redis, Logstash, Kibana, Microsoft Azure, Celery, Kubernetes HorizontalPodAutoscaler (HPA), Role-based Access Control (RBAC), Cloud Architecture
DevOps Engineer
2021 - 2022
Allinfra Ltd
- Developed a Python tool to manage multiple deployments of the same Helm chart. The configuration for each Helm release was kept and managed using a MongoDB database.
- Configured continuous integration pipelines for all repositories using CircleCI.
- Created and maintained the entire infrastructure in AWS and Kaleido using Terraform.
Technologies: Amazon Web Services (AWS), Docker, Terraform, Kubernetes, CircleCI, Helm, DevOps, CI/CD Pipelines, Infrastructure as Code (IaC), Cloud Infrastructure, Configuration Management, Site Reliability Engineering (SRE), Containers, Continuous Delivery (CD), Continuous Integration (CI), Amazon EC2, Amazon Elastic Container Service (ECS), Serverless Architecture, Amazon EKS, Microservices, RabbitMQ, Unix, New Relic, Monitoring, Performance Analysis, Containerization, DevOps Engineer, Staging, Ubuntu, GitHub Actions, Redis, Amazon RDS, Amazon CloudWatch, Amazon Linux, Amazon DynamoDB, Role-based Access Control (RBAC)
DevOps Engineer
2018 - 2019
Ascendro (MVI, BMW)
- Administered to the Kubernetes clusters, which included maintenance, improvements, deployments, etc.
- Migrated a Node.js and PHP application based on microservices from a traditional data center to AWS (Amazon Elastic Container Service).
- Wrote AWS CloudFormation code to provision the AWS infrastructure.
- Installed and configured Jenkins and created Jenkins jobs for continuous integration (CI).
- Monitored the implementation of Nagios and the development of WebInject plugins for several services.
- Deployed and customized Jira to fulfill client requirements and needs, including plugin development.
Technologies: Confluence, Jira, Bitbucket, GitLab, Nagios, Jenkins, Kubernetes, Amazon Web Services (AWS), CI/CD Pipelines, Infrastructure as Code (IaC), Cloud Infrastructure, Configuration Management, Site Reliability Engineering (SRE), Containers, Continuous Delivery (CD), Continuous Integration (CI), Amazon EC2, Amazon Elastic Container Service (ECS), AWS Lambda, Serverless Architecture, Microservices, Keycloak, RabbitMQ, ECS, Unix, Monitoring, Datadog, Performance Analysis, Containerization, DevOps Engineer, Staging, Ubuntu, Docker Swarm, Amazon RDS
DevOps Engineer | Python Developer
2017 - 2018
Undisclosed Client
- Built a Python back end using the Flask framework for a tool to support deploying on a platform based on AWS and Kubernetes.
- Developed Helm charts for Kubernetes. Automated the deployment process using CircleCI.
- Deployed and wrote Python libraries to use the APIs of the following tools: GitHub Enterprise, CircleCI, Quay, and Vault.
- Implemented continuous integration using CircleCI.
Technologies: Vault, Quay, CircleCI, GitHub, Helm, Kubernetes, PostgreSQL, Flask, Python, Amazon Web Services (AWS), CI/CD Pipelines, Cloud Infrastructure, Configuration Management, Containers, Continuous Integration (CI), Serverless Architecture, Microservices, Unix, Monitoring, Containerization, DevOps Engineer, Ubuntu
DevOps Engineer
2017 - 2017
Orange
- Deployed infrastructure as code (IaC) using Terraform on an OpenStack-based cloud.
- Managed the cloud instances and infrastructure (OpenWatt, CloudWatt).
- Automated the infrastructure's ad application configuration using Ansible or Salt.
- Implemented continuous integration and continuous delivery using Jenkins and GitLab CI.
- Deployed and configured the monitoring using Sensu and Prometheus.
- Deployed and configured the centralized logging system using Rsyslog, Logstash, Fluentd, Elasticsearch, and Kibana.
Technologies: Confluence, Jira, Rsyslog, Fluentd, ELK (Elastic Stack), Prometheus, Sensu, GitLab, GitHub, Jenkins, Secure Automated Lending Technology (SALT), Ansible, Terraform, OpenStack, CI/CD Pipelines, Cloud Infrastructure, Configuration Management, Chef, Puppet, Containers, Continuous Integration (CI), AWS Lambda, Amazon EKS, Unix, Monitoring, Containerization, OpenShift, DevOps Engineer, Ubuntu, Docker Swarm, Elasticsearch, Logstash, Kibana, Amazon Linux
DevOps Engineer
2016 - 2017
Ubix
- Constructed the AWS infrastructure, deployed the necessary resources, and implemented the security.
- Installed continuous integration using Git and Jenkins.
- Wrote a number of different scripts using Bash, Scala, Python, and Ansible.
- Migrated from Pivotal tracker to GitHub Issues and Overv.io (automatically performed by Python scripts).
- Maintained, developed, and permanently optimized Docker images.
- Migrated all documentation from a web wiki to GitHub into MD files using Grip.
- Built and maintained private repositories for npm (Sinopia), Bower (private-bower), and APT.
- Wrote, installed, and configured scripts for Spark, Hadoop, Cassandra, DataStax OpsCenter, ZooKeeper, Kafka, Kafka Manager, Elasticsearch, and Kibana (for both macOS and Ubuntu).
Technologies: ELK (Elastic Stack), Apache ZooKeeper, Apache Kafka, Cassandra, Docker Compose, Docker, Ansible, Python, Scala, Bash, Git, Jenkins, Amazon Web Services (AWS), CI/CD Pipelines, Containers, DevOps Engineer, Ubuntu, Amazon Linux
IT Specialist
2013 - 2016
IBM
- Implemented the full configuration of VMware ESX and vCenter (VMs, templates, networking, and storage).
- Set up and maintained Active Directory and LDAP; also onboarded the new customers.
- Built and supported the DNS; also onboarded the new customers.
- Installed and configured security and compliance tools (like Tivoli Security Compliance Manager, AppScan, Nessus, QRadar) and used them to generate reports and fix vulnerabilities or non-compliances.
- Developed Bash, Perl, and Python scripts to automate several processes.
Technologies: Nessus, Perl, Bash, Linux, Windows, VMware, IT Systems Engineering, MySQL, Microsoft SQL Server, Ubuntu, Docker Swarm
System Administrator
2012 - 2013
PJ Interactive Romania SRL (PJ Media Group)
- Constructed a network operation center that was able to monitor servers and monitor all over the globe: the majority of my work was on this.
- Monitored the performance with Nagios (and several plugins: NagVis, NConf, PNP4Nagios, FusionReactor, and so on), which was eventually replaced with a PRTG network monitor.
- Deployed and configured Redmine, a flexible project management web application, and customized it by writing PHP scripts.
- Deployed, configured, and maintained various tools, including Splunk (logging), OSSEC, Scrutinizer (monitoring), and Twiki (documentation).
- Implemented a PBX system inside the office using the Asterisk framework.
Technologies: Splunk, TWiki, Asterisk, OSSEC, Redmine, Paessler PRTG API, Nagios, PHP, Bash, Linux, Windows, VMware, MySQL, Ubuntu
System Administrator
2010 - 2012
Asentinel
- Implemented virtualization in the company including the installation and administration of ESXi 5.
- Installed, configured, and administered a virtualized Windows Domain Controller (Active Directory) and Linux servers.
- Wrote various scripts (Shell, Bash, Batch) for service automation and backup (databases, Subversion, and so on).
- Implemented, customized, and managed databases (Oracle).
- Installed, configured, and administered to web servers (Resin, Tomcat, WebSphere, WebLogic) and implemented application testing on each of them.
- Migrated all of the repositories from VSS to SVN. Later, all the SVN repositories were migrated to Git.
Technologies: Subversion (SVN), Git, WebLogic, WebSphere, Apache Tomcat, Resin, Oracle, Bash, Linux, Windows, VMware, MySQL, Ubuntu
Junior Programmer
2009 - 2009
Business & Decision
- Tested various projects in different environments like Windows XP or Linux (Ubuntu 9.04).
- Collected errors from logs and reported them in a bug tracker (Jira).
- Wrote Selenium test cases to run on Hudson: Selenium tests were developed using Java and Python.
- Installed and configured Linux servers. Used multiple distributions, both Debian- and Redhat-based ones.
- Developed Bash scripts to automate some manual tasks.
Technologies: Selenium, Hudson, Oracle, MySQL, PostgreSQL, PHP, Bash, Linux, Ubuntu
Experience
Migration of a Web Application
https://www.locarl.de/For this project, I migrated a web application based on microservices (composed of a mix of Node.js and PHP services) from a traditional data center to AWS Elastic Container Service—all without any downtime.
Building an Infrastructure to Support Mobile Development
Here, I worked as part of a team of two to build the entire infrastructure for Orange Dialer development.
Building a Startup's Infrastructure
Here, I worked as part of the team that was building the infrastructure for a big data platform. Specifically, I built up the AWS infrastructure, Docker images, and continuous integration flows.
Education
2008 - 2012
Bachelor's Degree in Computer Science and Information Technology
Politehnica University - Bucharest, Romania
Certifications
AUGUST 2025 - AUGUST 2027
HashiCorp Certified: Terraform Associate
HashiCorp
JUNE 2025 - PRESENT
Kubestronaut
Cloud Native Computing Foundation
JUNE 2025 - JUNE 2027
Certified Kubernetes Application Developer
Cloud Native Computing Foundation
MAY 2025 - MAY 2028
AWS Solutions Architect Associate
Amazon Web Services
APRIL 2025 - APRIL 2027
Certified Kubernetes Security Specialist
Cloud Native Computing Foundation
MARCH 2024 - MARCH 2027
Certified Kubernetes Administrator
Cloud Native Computing Foundation
FEBRUARY 2020 - FEBRUARY 2022
Docker Certified Associate
Docker, Inc.
OCTOBER 2017 - OCTOBER 2020
Red Hat Certified Engineer
Red Hat, Inc.
MARCH 2015 - OCTOBER 2020
Red Hat Certified System Administrator
Red Hat, Inc.
Skills
Libraries/APIs
GitHub API, Amazon API, Paessler PRTG API, Jenkins Pipeline, Jenkins Job DSL, OpenAPI
Tools
Helm, Grafana, Jenkins, Ansible, Terraform, Azure Kubernetes Service (AKS), Amazon Elastic Container Service (ECS), Kubernetes HorizontalPodAutoscaler (HPA), Git, CircleCI, Postman, AWS CloudFormation, Kibana, Logstash, Fluentd, Nagios, VMware, Amazon EKS, RabbitMQ, Amazon CloudWatch, Hudson, Apache Tomcat, Subversion (SVN), Asterisk, Splunk, GitHub, Vault, GitLab, Jira, Confluence, Docker Compose, GitLab CI/CD, Bitbucket, Rsyslog, ELK (Elastic Stack), Apache ZooKeeper, NPM, Bower, Android APT, DataStax, DataStax OpsCenter, IBM Security AppScan, Nessus, IBM QRadar, OSSEC, Redmine, SaltStack, Telegraf, NGINX, Loki, Certbot, Velero, Chef, Puppet, Keycloak, Docker Swarm, SendGrid, Kubernetes Operators, Celery, Packer, Kustomize
Languages
Bash, Python, Bash Script, PHP, Perl, Scala, Python 3, C#
Paradigms
DevOps, Continuous Delivery (CD), Continuous Integration (CI), Serverless Architecture, Microservices, Role-based Access Control (RBAC), Agile Software Development, Azure DevOps, HIPAA Compliance, API/Services Architecture, Event-driven Architecture
Platforms
Linux, Kubernetes, Amazon Web Services (AWS), Azure, Docker, Amazon EC2, Unix, Ubuntu, Amazon Linux, Windows, AWS Lambda, New Relic, Oracle, TWiki, OpenStack, Sensu, Apache Kafka, WebSphere, Amazon, Mailgun, Kaleido, OpenShift, Google Cloud Platform (GCP)
Frameworks
Windows PowerShell, Selenium, Flask, OAuth 2, Flux
Storage
MongoDB, PostgreSQL, MySQL, Elasticsearch, Microsoft SQL Server, Redis, Amazon DynamoDB, Cassandra, InfluxDB, Datadog
Other
Prometheus, CI/CD Pipelines, Infrastructure as Code (IaC), Cloud Infrastructure, Site Reliability Engineering (SRE), Containers, IT Systems Engineering, GitOps, Containerization, DevOps Engineer, Staging, Microsoft Azure, Cloud Architecture, Scripting, Configuration Management, Argo CD, ECS, Monitoring, Performance Analysis, Amazon RDS, Resin, Quay, Secure Automated Lending Technology (SALT), WebLogic, ARM, Seq, Linkerd, Snyk, Kubernetes Event-driven Autoscaler (KEDA), Programming, Software, Electronics, GitHub Actions, Cloudflare, Large Language Models (LLMs), Honeycomb, OpenTelemetry, Kubernetes Security, Architecture, Infrastructure Automation, API Design, K3s, Kyverno
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