Aleksander Korzynski, Developer in Warsaw, Poland
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Aleksander Korzynski

Verified Expert  in Engineering

DevOps Engineer and Linux Software Developer

Location
Warsaw, Poland
Toptal Member Since
July 20, 2021

Aleksander is a veteran Linux engineer who helps organizations achieve strategic software delivery goals, such as agility, reliability, and security. As a Toptal/Google contractor, he designed a CD pipeline supporting almost 1,000 developers. At the University of Cambridge, he tuned the performance of applications in a >£1 million Linux HPC cluster. Aleksander can configure the cloud, CI/CD, and release automation.

Portfolio

Priceline
Bash, Bash Script, JavaScript, Python, CI/CD Pipelines, GitHub, Git, Git Repo...
DevOpsera
Linux, WordPress, OpenStack, Python, HTML, CSS, JavaScript, Bash, Elementor...
Hewlett Packard Enterprise
Linux, Jenkins, Chef, Git, Bash, Python, Gerrit, Ubuntu, OpenStack, DevOps...

Experience

Availability

Part-time

Preferred Environment

Linux, DevOps, Python, Bash, CI/CD Pipelines, Docker, Kubernetes, Google Kubernetes Engine (GKE), Google Compute Engine (GCE), Argo CD

The most amazing...

...system I've developed was a comprehensive CI/CD pipeline for tracking the OpenStack project, supporting changes from over 10,000 open-source developers.

Work Experience

Linux DevOps Engineer – Harness, Argo CD, GitHub Actions

2021 - PRESENT
Priceline
  • Designed and implemented a new CD system, used by almost 1,000 software engineers.
  • Provided support to the engineers using the CI/CD pipeline.
  • Responded to internal auditors on PCI and SOX compliance.
Technologies: Bash, Bash Script, JavaScript, Python, CI/CD Pipelines, GitHub, Git, Git Repo, Nexus, Nexus IQ, Argo CD, DevOps, Linux, Ubuntu, Ubuntu Linux, Ubuntu Server, DevOps Engineer, YAML, Ansible, Google Cloud Platform (GCP), Google Kubernetes Engine (GKE), Docker, Scripting, Shell Scripting, Unix Shell Scripting, SOX Compliance, SOX, PCI Compliance, Google Compute Engine (GCE), Google Cloud, Kubernetes, Splunk, New Relic, Containers, Data Structures, Infrastructure as Code (IaC), Site Reliability Engineering (SRE), Solution Architecture, Cloud Computing, Architecture, GitOps, Helm

Independent Consultant – Linux, DevOps and Web

2019 - PRESENT
DevOpsera
  • Conducted an audit of an OpenStack public cloud installation, saving the client costly support issues down the road.
  • Consulted a client on setting up a CI system for building Ubuntu Linux software packages, greatly simplifying the solution they planned and saving them time and money.
  • Managed software projects to develop and/or migrate about five WordPress websites, applying Kanban to achieve agility.
  • Managed and mentored a software engineer to develop a bespoke Python script for promoting online events on Meetup.com.
  • Hosted regular online events for tech leaders and built a community of nearly a thousand people.
  • Automated audio transcriptions with Google Cloud.
  • Built processes for business development using open-source technologies, such as Groundhogg CRM and Kanboard.
Technologies: Linux, WordPress, OpenStack, Python, HTML, CSS, JavaScript, Bash, Elementor, Agile Project Management, Kanban, DevOps, Lean, Business Development, Intellectual Property, Software Development, IP Networks, Git, Debian, Apache, MySQL, XML, Vagrant, System Administration, XSLT, DocBook, Docker, Private Clouds, Bash Script, Ubuntu Server, Debian Packaging, Shell Scripting, Groundhogg CRM, Google Cloud Platform (GCP), GitLab, GitLab CI/CD, Git Flow, Git Repo, Continuous Delivery (CD), Continuous Integration (CI), Continuous Deployment, Continuous Development (CD), Google Cloud, Site Reliability Engineering (SRE), Cloud Computing, Scripting, GitOps

Linux DevOps Engineer – OpenStack

2011 - 2019
Hewlett Packard Enterprise
  • Led the development of a downstream CI/CD system for OpenStack, capable of processing changes from over 10,000 open-source developers.
  • Developed an extension to Git that allows for tracking patches on top of an open-source project by combining the advantages of Git merges and rebases.
  • Co-developed the code for deploying OpenStack to a virtual test environment using the same Chef recipes as in production.
Technologies: Linux, Jenkins, Chef, Git, Bash, Python, Gerrit, Ubuntu, OpenStack, DevOps, Perl, CI/CD Pipelines, Software Development, Object-oriented Programming (OOP), IP Networks, Relational Databases, HTML, CSS, Kanban, Red Hat Linux, Refactoring, Scrum, System Administration, Private Clouds, GitFlow, Bash Script, Ubuntu Server, Debian Packaging, Shell Scripting, Git Flow, Git Repo, Continuous Delivery (CD), Continuous Integration (CI), Continuous Deployment, Continuous Development (CD), Data Structures, Solution Architecture, Cloud Computing, Architecture, Scripting, Red Hat Enterprise Linux

Linux Engineer – HPC

2009 - 2011
University of Cambridge (ClusterVision)
  • Developed software for monitoring a high-performance computing (HPC) cluster, including OO analysis and design.
  • Participated in a supercomputer performance research project on behalf of the University of Cambridge. Tuning the compiler, communications, OS, and applications.
  • Tuned the performance of applications in a €15 million Linux HPC cluster at the Julich Supercomputing Centre, Germany–the fastest computer in Europe.
  • Tuned the performance of applications in a >£1 million Linux HPC cluster at the University of Cambridge, UK–the fastest x86 computer in the UK in 2006.
  • Resolved performance issues for researchers running HPC code in Linux clusters.
Technologies: Linux, Java, Apache Tomcat, Apache, Perl, MySQL, Google Web Toolkit, Object-oriented Programming (OOP), Object-oriented Design (OOD), Object-oriented Analysis & Design (OOAD), PHP, Refactoring, Software Design Patterns, Performance Tuning, DevOps, Bash, Software Development, SQL, IP Networks, Relational Databases, HTML, CSS, JavaScript, Fedora, Scientific Linux, System Administration, Private Clouds, Bash Script, Shell Scripting, Microsoft HPC, High-performance Computing (HPC), Torque, Site Reliability Engineering (SRE), Cloud Computing, Scripting

Linux Engineer – HPC

2009 - 2009
University of Birmingham (ClusterVision)
  • Reorganized the storage for a £2.6 million Linux parallel compute cluster, increasing resilience and supportability for the in-house system administrator team.
  • Developed health checking and self-healing scripts for the Linux cluster, fixing computational performance issues.
  • Transferred knowledge about the cluster to in-house system administrators.
Technologies: Linux, GPFS, Perl, Bash, IBM Storage, DevOps, Software Development, IP Networks, Scientific Linux, Performance Tuning, System Administration, Private Clouds, Bash Script, Shell Scripting, Microsoft HPC, High-performance Computing (HPC), Site Reliability Engineering (SRE), Cloud Computing, Scripting

Linux Software Developer

2007 - 2008
ClusterVision
  • Co-developed software for managing Linux high-performance compute clusters. Built a data collection mechanism that scales to 1,000s of nodes.
  • Increased the performance of the pre-existing cluster management code by several factors. Introduced code profiling tools into the team.
  • Developed internal software for managing support engineers' access to environments belonging to our clients.
  • Developed internal software for monitoring the activity of support engineers on machines belonging to our clients.
Technologies: Linux, C++, Standard Template Library (STL), Boost, Perl, Bash, XML, OpenSSL, VMware, MySQL, Subversion (SVN), Object-oriented Programming (OOP), Object-oriented Design (OOD), Software Design Patterns, DevOps, C, Software Development, SQL, IP Networks, Relational Databases, Debian, Red Hat Linux, CentOS, Refactoring, Performance Tuning, System Administration, Private Clouds, Bash Script, Shell Scripting, Microsoft HPC, High-performance Computing (HPC), Data Structures, Scripting, Red Hat Enterprise Linux

A Beginner's Book on Linux

https://userbie.com/get-started
Co-authored an online book entitled "Get Started on Linux by End of Tonight – Without Breaking Your Box." Modified existing Bash, Perl, and XSLT code to have DocBook generate special feedback links at the end of every paragraph so that readers can easily provide feedback. Converted the book into an online course based on WordPress and LearnDash.

CI/CD System for OpenStack

https://devopsera.com/2014/04/federative-continuous-integration/
Developed a downstream CI/CD system for OpenStack, a project having as many as 50 changes per day produced by tens of thousands of open-source developers. To maintain temporary patches on top of OpenStack without forking from the open-source community, I led the development of special extensions to Git. The extensions allow us to submit our patch to the community, incorporate the feedback from the community, and, once the patch is accepted, remove the temporary patch from the in-house version. We have designed a new Git operation the combines the advantages of Git merges and rebases without the disadvantages. Our extensions allow us to clearly distinguish our temporary patches from the rest of commits without breaking backward compatibility.

Linux Kernel-level Checkpoint and Recovery

https://2006.dsn.org/FinalProgram.pdf
An implementation of checkpoint and recovery in the OpenSSI kernel-level clustering platform for Linux. Analyzed the problem, reverse-engineered the undocumented C source code of OpenSSI, and implemented selected elements of the mechanism. I published a paper related to the project at the student forum of an IEEE/IFIP conference in the USA. Received an award for the paper from the IEEE-CS Technical Committee on Fault-tolerant Computing. I completed this work for my master's thesis.

CD-based Distribution of Minix

http://studia.elka.pw.edu.pl/prog/minix/
This was the first distribution of the Minix operating system that could be booted from a CD. The idea for the project originated from an academic professor at the Warsaw University of Technology, where I was a student. The work included programming in C to implement the new functionality in the Minix kernel. The distribution had tens of thousands of users worldwide and was mirrored on the website of one of the co-authors of the famous operating systems book, Albert S. Woodhull.

ReplayGain Implementation in the LAME MP3 Encoder

https://svn.code.sf.net/p/lame/svn/trunk/lame/doc/html/history.html
Implemented a new feature in the most popular MP3 encoder in the world. The feature ensures that different songs are played at the same perceived volume so that the listener does not have to reach the volume knob every time a different song is played. My work involved C programming to integrate the ReplayGain standard into the LAME MP3 encoder, which has millions of users.
2015 - 2017

Postgraduate Diploma in Entrepreneurship

Lazarski University - Warsaw, Poland

2001 - 2007

Master's Degree in Computer Science

Warsaw University of Technology, Faculty of Electronics and IT - Warsaw, Poland

1997 - 2001

Diploma in Mathematics and Physics

Stefan Batory High School - Warsaw, Poland

OCTOBER 2011 - OCTOBER 2013

Certified Scrum Master

Scrum Alliance

Libraries/APIs

Microsoft HPC, Standard Template Library (STL), OpenSSL

Tools

Git, GitHub, Jenkins, GitLab, GitLab CI/CD, Torque, Helm, Chef, Gerrit, Apache Tomcat, Apache, VMware, Subversion (SVN), Vagrant, LearnDash, CVS, GCC, Ansible, Google Kubernetes Engine (GKE), Google Compute Engine (GCE), Splunk

Languages

Bash, Bash Script, Python, Perl, C, C++, SQL, HTML, CSS, XML, DocBook, Java, PHP, JavaScript, XSLT, YAML

Paradigms

DevOps, Object-oriented Programming (OOP), Refactoring, Continuous Delivery (CD), Continuous Integration (CI), Continuous Deployment, Continuous Development (CD), High-performance Computing (HPC), Agile Project Management, Kanban, Object-oriented Design (OOD), Object-oriented Analysis & Design (OOAD), Scrum

Platforms

Linux, OpenStack, WordPress, Ubuntu, Debian, Kubernetes, Docker, Google Cloud Platform (GCP), Software Design Patterns, Red Hat Linux, CentOS, Fedora, Nexus, Ubuntu Linux, New Relic, Red Hat Enterprise Linux

Frameworks

Google Web Toolkit, Boost

Storage

Relational Databases, GPFS, Google Cloud, MySQL

Other

CI/CD Pipelines, Software Development, System Administration, Performance Tuning, GitFlow, Shell Scripting, Debian Packaging, Ubuntu Server, Git Flow, Git Repo, Scripting, Cloud Computing, GitOps, IP Networks, Elementor, Scrum Master, Groundhogg CRM, Argo CD, Site Reliability Engineering (SRE), Lean, Product Management, Business Development, Intellectual Property, IBM Storage, Scientific Linux, Reverse Engineering, Operating Systems, Private Clouds, Nexus IQ, DevOps Engineer, Unix Shell Scripting, SOX Compliance, SOX, PCI Compliance, Containers, Data Structures, Infrastructure as Code (IaC), Solution Architecture, Architecture

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