Bartosz Kruszelnicki
Senior Technical Engineer | Senior Middleware & Integration Specialist
Experience
Senior Middleware Engineer at Project InstantPayments 2.0 in Worldline (October 2018 - Present)
I joined the IP2.0 project approximately six months before the prod launch as part of my student internship program. The project is predominantly based on JAVA applications managed by JBOSS and AMQ servers. With my proficiency in LINUX, particularly with REDHAT 7+, I have been responsible for delivering comprehensive infrastructure setups for our clients over the past few years. This includes provisioning LINUX VMs, managing DB servers, configuring network rules, setting up load balancers, as well as deploying and maintaining JBOSS + AMQ environments. Additionally, I have handled Version Control Systems, automated deployment tools, and provided support for LDAP systems, particularly assisting the identity management group during issue resolutions. All of these responsibilities were carried out while being on-call 24/7 for production support.
I particularly enjoy troubleshooting and optimizing performance issues, making JAVA process tuning one of my core strengths. Given the complexity of the IP2.0 system, a lot of automation and scripting were required. My primary scripting languages are Python and Bash.
Over some time, I have also supported my managers in conducting technical interviews. Nowadays, I've been chosen as a single point of contact for our biggest clients.
Additionally, I have a passion for sharing knowledge and aiding in onboarding processes, as well as participating in new subprojects such as migrating the entire environment to OpenShift or Google Cloud.
The technology stack utilized in the projects include:
Top Strenght
Previous Experience
Throughout my high school years (2011 - 2014) at MAK-NET [Internet Service Provider], I served as a technical support specialist. My role encompassed a range of responsibilities, from configuring network devices to installing antennas and links, addressing clients' device issues, and troubleshooting connection hiccups. This multifaceted role immersed me in the intricacies of UNIX-based network infrastructure, particularly with the MIKROTIK variation, enhancing my expertise in this domain.
minor experience
between elementary school and starting university, I operated my own IT service venture, specializing in tasks like OS reinstalls doing some kind of SPA for devices. that time I initially engaged with LINUX/UNIX systems.
Education
Wrocław University of Science and Technology (2014 - 2018)
Bachelor of Science in Systems Engineering with specialization in control systems
Systems Engineering with
specialization of control systems
was great mixture of mentioned
technologies in folowing areas:
IT: including programming, DB, app design, OS knowledge
Automation & Robotics: Mainly in programming area, great example might be creating soft for lifts that control engine.
Al: machine learning algorithms for example face recognition, classifying texts
High School nr 1 in Kępno (2010 - 2014)
Specialization in Information Technology: Operating Systems and Computer Networks
Certificates & Trainings
- GOOGLE CLOUD - Associate Cloud Engineer Certification
- RHCSA (Red Hat Certified System Administrator)
- Kubernetes Administration (LFS458) [one-week training]
- Red Hat Custom Openshift On-site Training (CU-OCP-OS) [one-week training]
- JBOSS, APACHE, TOMCAT [one-week workshop]
About Me
My journey with ATOS started with a student internship. After getting an offer to join full-time and being part of the Instant Payments 2.0 project, I found a great fit for my passion for IT. I'm into tech and economics, so I spend a lot of my free time reading and learning new stuff. Oh, and I love hanging out with my two awesome parrots!
Contact Information
Email: bartosz.kruszelnicki1@gmail.com
Phone: +48 537-565-469
Home Lab Projects
Home Workstation: Virtualized Network Infrastructure
As a personal project on my home workstation, I developed a fully virtualized network infrastructure that serves as a multi-functional environment for various IT services. Here’s a breakdown of the key elements:
- File Server for Local Network: Set up a dedicated file server for seamless local file sharing across the network.
- Web Servers with Auto-Renewing SSL Certificates: Hosted several websites accessible over the internet, with SSL certificates that automatically renew on a weekly check using Let's Encrypt. All services are available over HTTPS.
- Fedora and Ubuntu Virtual Machines (VMs): Managed over six VMs running either Fedora or Ubuntu. These machines are integrated with LDAP, ensuring unified user management across the entire environment.
- Monitoring with Prometheus, Zabbix, and Grafana: Each VM and the workstation itself are continuously monitored using Prometheus and Zabbix, with Grafana providing real-time dashboards for system metrics such as CPU usage, memory, filesystem status, and CPU clock speed. Additional custom metrics include:
- The number of banned IP addresses (via Fail2Ban).
- Total IP bans, unbanned IPs, and blocked connections.
- LDAP Authentication Across Components: All critical components, including Zabbix, Grafana, Jenkins, and Kubernetes, are secured with centralized LDAP-based authentication, ensuring a consistent user experience.
- Jenkins CI/CD with Kubernetes: Configured Jenkins to build and deploy application images into the Kubernetes clusters running on the VMs. Jenkins itself, along with Kubernetes services, is secured via LDAP credentials.
- Kubernetes Cluster Hosting Websites: The Kubernetes cluster manages and hosts these websites and several others, leveraging a proxy and ingress for efficient traffic routing and load balancing between the hosted services.
- Fail2Ban Security Layer: To enhance security, the workstation is open to the internet and secured with Fail2Ban, which automatically bans IP addresses after two failed login attempts, with a ban duration of 48 hours.
- Secure Communication: All communications between services (HTTPS, LDAPS) are encrypted to ensure the confidentiality and integrity of data.
