Tobias Sarnowski




I am a passionate software developer since 1997. My strength is my allround knowledge from low-level operating systems and assembler up to Clojure and the Cloud. Coupled with a solid understanding of security topics and distributed systems, I am able to design and analyze complex, networked architectures. In parallel, I am cooperating with stakeholders to distill their functional requirements without mixing technical decisions into it. My broad knowledge and toolset allows me to find simple solutions to functional requirements.


Work Experience

Zalando SE

Infrastructure Lead Architect

2016 - Present

Defining and executing the overall IT infrastructure product vision; being responsible for the planning and prioritization of all infrastructure projects. Developing a clear long term strategy for Zalando's Technology Infrastructure. Supporting all teams in contributing to the strategy and supporting all major projects to result in great user experiences. The Tech. Infrastructure consists of Networking across all sites (offices, warehouses, data centers), Hardware lifecycle of servers and storage systems, Operating system management (Linux, Solaris, Windows), Monitoring (Server, Backends, End User), Log collection, DDoS protection, Domain management, Certificate management, Identity & Access Management, Central Audit Trail, Billing of all costs to our cost centers and customers, Managed access to Amazon Web Service accounts, Managed Continuous Delivery infrastructure and Managed Databases (PostgreSQL, Cassandra).

  • Introduction of Kubernetes as the base for all future operations of Zalando's Tech teams.
  • Inception of an own Identity & Access Management infrastructure tailored to Zalando's specific needs.

Zalando SE

Cloud Architect

2014 - 2016

Designing, developing and rolling out processes, systems and good practices in order to bring Zalando Technology from data centers into the Cloud.

  • Design, development and operations of STUPS ( to allow Zalando to work on Amazon Web Services (AWS).
  • Consulting for all Zalando teams to build Cloud-ready software and processes.

Zalando GmbH

Team Lead

2012 - 2014

Leading the 'Order Team', that builds the software which processes all sales orders Zalando receives. The system manages the processes of creating sales orders, handling payment options, coordinating logistics processes, processing returns and refunding customers while also coordinating with the SAP accounting systems and the customer care tooling. When I started, the system handled $300mio revenue while serving 5 countries with two warehouses. I left the team handling $2bn yearly revenue while serving 13 countries with 4 warehouses. The team grew from 6 to 22 people.

  • Delivered a system that ran high-available 24x7 and served all our customers while handling accounting and coordinating logistics.
  • Formalized the whole sales and return order processes with BPMN 2.0 and introduced a BPMN engine that scales and uses the BPMN flows to process the orders.
  • Integrated our custom services with SAP FI-CA to use SAP's accounting capabilities within 3 months.

CosmoCode GmbH

Team Lead, Senior Software Engineer

2009 - 2012

Designing, developing and launching various kinds of web, mobile and embedded applications.

CosmoCode GmbH

Software Engineer

2006 - 2009

Designing, developing and launching various kinds of web applications.


  • Cloud Infrastructure

    • Distributed Systems
    • Security
    • Identity & Access Management
    • Container Orchestration
    • Kubernetes
  • Software Development

    • Clojure
    • Golang
    • Java
    • Shell
    • Python
    • PHP
    • HTML
    • CSS
    • JavaScript
    • C
    • Lua
    • TCL
    • Assembler
  • Project Management

    • Continuous Delivery
    • Kanban
    • eXtreme Programming
  • Operations

    • Amazon Web Services
    • Bare Metal
    • Linux
    • OpenBSD
  • Databases

    • Cassandra
    • etcd
    • PostgreSQL
    • MySQL