Viktor Loosz, Distributed Systems Developer in Hungary
Viktor Loosz

Distributed Systems Developer in Hungary

Member since November 13, 2019
Viktor is a seasoned DevOps engineer with several years of experience who's worked for major companies (AWS), and he joined Toptal to look for remote side projects. He feels confident with Linux- and Unix-based systems and has led small teams of 5-6 people. Viktor knows the ins and outs of SDLC and how to successfully deploy and manage vast numbers of servers and microservices with a high level of automation and minimal manual intervention.
Viktor is now available for hire


  • Adevinta
    Amazon Web Services (AWS), DevOps, Linux, Travis CI, Spinnaker, Kubernetes...
  • Amazon Web Services
    Amazon Web Services (AWS), DevOps, Linux, AWS
  • Virgo Systems
    Amazon Web Services (AWS), Linux, BGP, Networks, Firewalls, Java, PHP, VMware...






Preferred Environment

Apache Kafka, Amazon Web Services (AWS), DevOps, Linux, Continuous Delivery (CD), Continuous Integration (CI), AWS, Python, Git

The most amazing...

...project I've worked on was running and managing hundreds of servers with three people in a 24/7 rotation without pages for months.


  • Staff DevOps Engineer

    2018 - PRESENT
    • Worked as part of a team that builds and runs (you build it, you run it) managed Kafka and Cassandra services for our internal customers.
    • Operated and managed a huge Kafka and Cassandra infrastructure.
    • Designed an authentication and authorization system for general use (OIDC based with an external IDP).
    • Shared knowledge about Kafka in workshops with our internal teams.
    • Worked with customers on different projects regarding integrations to our components, providing solutions for networking.
    Technologies: Amazon Web Services (AWS), DevOps, Linux, Travis CI, Spinnaker, Kubernetes, Python, Cassandra, Apache Kafka, AWS
  • Systems Engineer

    2016 - 2018
    Amazon Web Services
    • Worked as part of a team that managed and maintained several internal and external tools of the relational database service (RDS) platform.
    • Managed all customer's RDS instances and their data.
    • Served as part of the on-call rotation for the whole RDS platform.
    • Developed internal consoles and maintenance tools.
    • Designed the console’s architecture (monitoring and alarming).
    • Implemented automated testing with infrastructure standard tools.
    Technologies: Amazon Web Services (AWS), DevOps, Linux, AWS
  • Lead Systems Engineer

    2012 - 2016
    Virgo Systems
    • Led the operations team.
    • Designed and built EÉR (electronic sales system).
    • Built and maintained E-Digital (a market leader webshop in Hungary).
    • Managed projects in public cloud services (AWS).
    • Designed the architecture and implemented the electronic toll system (HU-GO), the national mobile payment system (NMFR), and the electronic public road trade control system (EKÁER).
    • Managed Hungary’s biggest social network site (
    • Designed and maintained our clients’ systems (, MTT, NPLI,, and more).
    Technologies: Amazon Web Services (AWS), Linux, BGP, Networks, Firewalls, Java, PHP, VMware, RHEL, AWS


  • Authentication System

    I designed an authentication system that acts as a proxy in front of the application (called service) that needs to be protected. The service's code does not have to be modified as the proxy handles the authentication and authorization. Most of the components are built on top of open-source libraries and projects.

    The project is in use for securing an in-house Kafka API.

  • Zero-downtime Migration of Kafka Clusters

    I designed a way of migrating data (topics, ACLs, and more) without downtime on several production Kafka clusters. The execution was mostly automated with tested scripts (mostly Python) with a runbook (set of instructions) for the manual actions. The migration was challenging because the customer had connections from different sources (VPC, VPC peering, direct connect, internet, and over VPC as well).

  • Automated E2E Testing of Internal Components

    I designed and developed an end-to-end testing framework to test an internal console in a CI/CD pipeline. The codebase was designed in a way that it is reusable and the underlying components can be replaced with other technologies.


  • Languages

    PHP, Python
  • Tools

    Ansible, AWS CloudFormation, Git, Travis CI, Chef
  • Paradigms

    DevOps, Continuous Integration (CI), Continuous Delivery (CD), Agile
  • Platforms

    Amazon Web Services (AWS), Linux, Apache Kafka, Docker, MacOS, Spinnaker, Kubernetes
  • Storage

    MySQL, Cassandra
  • Other

    AWS, Scalability, Networks, Distributed Systems, Virtualization, Apache Cassandra, RHEL, Firewalls, BGP


  • Certified Kubernetes Administrator
    DECEMBER 2019 - DECEMBER 2022

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