Go · REST API
openvpn-mng
Web-based management system for OpenVPN users, groups, networks, and access control with fine-grained permissions.
★ 9 stars · 5 forks
✍ Read article on MediumDevOps · SRE · Network Automation · Ethical Hacker · BI Architect
MAKINGINFRAbulletproofSINCE '02
Stepan Kutaj — Network Automation Engineer at Red Hat, infrastructure engineer at OpenSSL Corp, and founder of TLDR;IT in Brno. I build Kubernetes platforms and Linux infrastructure for banks, energy and online betting clients across Europe, the Middle East and Africa. Two decades of keeping things alive at 3am.
01Network Automation Eng.Red Hat
02Infrastructure Eng.OpenSSL Corp.
03Founder & PrincipalIT Consulting, Brno
§ 01Technical StackLanguages · Platforms · Tools
The tools
of the
trade
Container & Orchestration
- Kubernetes
- RedHat OpenShift / OKD
- Rancher · Fleet GitOps
- Helm · Argo CD
- Longhorn Storage
- cert-manager
- Docker
Infrastructure as Code
- Terraform
- Ansible (27 roles)
- Pulumi
- HashiCorp Vault
- Jenkins · GitHub Actions
- Prometheus · Grafana
- ELK Stack · Kafka
Programming
- Go
- Python
- C++
- Rust
- Java / Spring Boot
- Django · Flask
- PHP · .NET
- React · Next.js
Cloud & Networking
- Linux (RHEL · Debian · SuSE)
- AIX · HP-UX · Solaris
- AWS · GCP · IBM Cloud
- OVH · vRack
- PowerDNS · OpenVPN
- iptables · nginx
- Postfix · Dovecot
Security & Monitoring
- Ethical Hacking
- Wazuh SIEM
- Greenbone / OpenVAS
- Penetration Testing
- Network Scanning
- Fail2ban · Rspamd
- Vault Secrets Mgmt
Data, BI & Messaging
- IBM Cognos BI / TM1
- PostgreSQL · Oracle DB
- Redis · RabbitMQ
- MinIO · Ceph · Kafka
- IBM Informix IDS
- QlikView
- MySQL · DB2
§ 02Experience20+ years · EMEA region
OpenSSL Software
Infrastructure Engineer
2026
Working on the infrastructure behind OpenSSL Software Services & Corporation — the cryptographic library most of the internet runs TLS on.
Red Hat
Network Automation Engineer
2025
Building network automation tooling in Go, Python, Terraform and Ansible. OKD/OpenShift. Contributing back to upstream open-source projects in the network automation space.
GoPythonTerraformAnsibleOKDOpenShift
TLDR;IT s.r.o.
Founder & Principal Engineer
2024 — Present
My own consultancy. Linux engineering, Ceph storage, Kubernetes and IBM Cognos BI work for Czech enterprise clients who need someone to own the whole stack.
KubernetesCephIBM CognosLinuxSecurity
IBM
Cognos Specialist
2014 — 2023
BI consultant on IBM Cognos, TM1 and QlikView, with projects in Sweden, Germany, Hungary, Belgium, Romania and the USA. In parallel, sysadmin on Carrefour's 3,000-server estate across AIX, Linux and HP-UX.
IBM CognosTM1QlikViewAIXHP-UXLinux3k Servers
Earlier career
2011
2014
2014
Freelancer
Independent Consultant
Cognos 8 BI consulting and planning. Unix server administration (HP-UX, AIX, Sun). Database support — Informix IDS and Oracle 9i/10g.
2007
2014
2014
HP
External Lecturer · Prague
Training users in HP-UX and Linux. Preparation of candidates for HP certification.
2004
2011
2011
S&T CZ
Senior System Specialist · Prague
Cognos 8 BI consulting, Unix administration (HP-UX, AIX, Sun), Oracle/Informix support, SAP on Linux, IBM Cognos testing with HPQC, performance testing via Apache JMeter, Sage & Glovia implementation.
2003
2004
2004
Macron Software
Developer & Sysadmin · Prague
PHP web application development with Sybase, Informix, MySQL. Unix server administration (SunOS, FreeBSD, Debian, RedHat, SuSE).
2002
2003
2003
Fast s.r.o.
Developer & Sysadmin · Prague
Network administration of 200 PCs and 15 servers. Accounting system admin, EDI and SAP implementation, shell scripting on Unix/MS-DOS.
§ 03Client ProjectsEnterprise · Banking · Government · Retail
SELECT
CLIENTS
20+ enterprise engagementsČEZ
2024 — 2025
OpenShift platform support for ČEZ and ČEZ IT. Wrote internal Kubernetes operators.
Freelance
CreativeDock
2024
SRE for end client Oredoo, a bank in Oman. Built Kubernetes clusters and databases, supported their dev teams, worked alongside security.
Freelance
VictoriaTECH / Sky Soft
2022 — 2026
Built 200+ Linux servers, Ceph storage and a Kubernetes cluster (1 TB RAM, 600 CPU cores) for an online betting platform in Africa. Networking and security set up end-to-end.
Freelance
Carrefour
2019 — 2023
L2/L3 support for 3,000 servers — AIX, Linux, HP-UX — and enterprise clusters (AIX Cluster, HP Serviceguard, Linux clusters).
via IBM
VF Corp.
2015 — 2023
Lead the Cognos administration team for VF Corp's apparel brands.
via IBM
IKEA
2014 — 2023
Technical consultant for iSOM Reporting project in Sweden. Implementing reporting solution with Sterling application.
via IBM
DHL
2014 — 2015
Team leader of Cognos administration from Hungary for DHL headquarters in Bonn, Germany.
via IBM
UCB Belgium
2015
Implemented full IBM Cognos BI portfolio (BI, TM1, Controller, DCM). Trained 5 administrators in Romania. Developed Active Reports dashboard for iPad.
via IBM
ING Insurance
2013
Wrote OSG security documentation for infrastructure and applications. Used for Dutch National Bank audit.
Freelance
Generali
2009 —
IBM Cognos 8 migration and support. Implemented IBM InfoSphere QualityStage, DWH integration and duplicate record consolidation.
via S&T CZ
Česká spořitelna
2006 —
Implemented IBM Cognos 8 BI and Oracle 10g. Performance testing with Apache JMeter.
via S&T CZ
Česká pošta
2005 —
IBM Cognos 8 BI and Oracle 10g on SuSE Enterprise Linux implementation and support.
via S&T CZ
Komerční banka
2010
Created testing plan, executed IBM Cognos application testing using HP Quality Center.
via S&T CZ
Metrostav
2011 —
Oracle 11g/10g support, RMAN, migration, Oracle Primavera implementation and DR strategy.
Freelance
Ministry of Labour & Social Affairs
2008 — 2011
Oracle geo-cluster with HP Serviceguard on HP-UX 11.31. Lecturing Arsys.X across employment offices nationwide.
Freelance / S&T CZ
Forbes CZ
2010
Oracle 10g RAC implementation on Red Hat Linux.
via S&T CZ
Škoda Praha
2004 — 2008
IBM Informix and SAGE application support on Sun Solaris for nuclear power plant engineering company.
via S&T CZ
CSA (Czech Airlines)
2004 — 2007
Support for mission-critical IBM Informix databases (safety & flight regularity systems) on Sun Solaris.
via S&T CZ
Raiffeisenbank Romania
2006
Cognos ReportNet implementation on AIX and technical consultation for Romanian operations.
via S&T CZ
§ 04Open Sourcegithub.com/tldr-it-stepankutaj
SELECT
WORKS
View all on GitHub ↗Go · Integration
openvpn-client
Go client that bridges an OpenVPN server with the OpenVPN Manager API. Production-ready, clean architecture.
★ 2 stars · 3 forks
✍ Read article on MediumGo · Security
pentakit
Extensible penetration testing toolkit. Modular CLI + interactive TUI automating recon, enumeration and exploitation workflows.
★ 1 star
C++ · Networking
network-scanner
High-performance ICMP/TCP network sweep scanner. Full CIDR support, RTT colour output, multithreaded.
★ 1 star
Ansible · Jinja
ansible_role
27 production-ready roles: security hardening, networking, databases, VPN, monitoring and Linux lifecycle management.
★ 1 star
Go · Shell · DevEx
setup-mac
One-command macOS workstation bootstrap. Sets up the full developer and sysadmin toolchain in one go.
★ 1 star
✍ Read article on Medium§ 05CredentialsCertifications · Courses
15+
EARNED
From Oracle Database in 2007 to Ethical Hacking in 2025. Two decades of vendor certifications from IBM, Oracle, HP, Red Hat and the Linux Foundation.
Licenses & Certifications
2025
Ethical Hacking
Certified Ethical Hacker (CEH)
2023
Kubernetes Administration
CNCF / Linux Foundation
2022
IBM Cognos Analytics Admin & Developer v11
IBM
2020
RedHat OpenShift 4 Administration
Red Hat
2016
Oracle Database SQL Certified Expert
Oracle
2016
Oracle Database 11g Administrator Certified Professional (OCP)
Oracle
2012
IBM Software Support Provider — First Level Support
IBM · ID: 205140T
2011
IBM Certified Solution Developer — InfoSphere QualityStage v8.5
IBM
2011
QlikView Support Certification for Partners
QlikTech
2010
IBM Cognos 8 Controller Technical Specialist
IBM
2010
IBM Cognos 8 BI Technical Specialist
IBM
2008
HP Certified Advanced System Administrator (HPUX11i CSE)
Hewlett-Packard
2007
HP Certified System Administrator (HPUX11i CSA)
Hewlett-Packard
Courses & Training
HPUX System & Network Admin IS&T CZ
IBM Informix IDS 9.40 AdministrationIBM / S&T CZ
IBM IDS 9.50 Enterprise ReplicationIBM / S&T CZ
IBM Cognos 8 BI AdministrationS&T CZ
IBM Technical Admin — Cognos 8 PlanningS&T CZ
Oracle 10G Real Application Cluster (RAC)S&T CZ
Sun Microsystems Java ProgrammingS&T CZ
§ 06ContactLet's build something
LET'SBUILDSOMETHINGSOLID.
Kubernetes architecture · Security audits · Infrastructure automation · Network engineering · IBM Cognos BI · Custom software. If it runs on Linux and needs to not fail — let's talk.