Kristijan Belošević, Developer in Zagreb, Croatia
Kristijan is available for hire
Hire Kristijan

Kristijan Belošević

Verified Expert  in Engineering

Software Developer

Zagreb, Croatia

Toptal member since June 30, 2020

Expertise
LinuxGrafanaTerraformDevOpsCloud ArchitectureAWS RDSAWS DevOpsSaaSDockerJiraKubernetesAWSAWS LambdaAWS IAM
Bio

Kristijan is an articulate DevOps engineer with over five years of experience performing diagnostics and achieving client goals. He is highly specialized and focuses on UNIX/Linux systems. Kristijan pays attention to details, deploying flawless CI/CD pipelines, databases, infrastructure, and performs thorough testing to ensure excellent performance.

Portfolio

Novorésumé ApS
Kubernetes, Helm, Terraform, DevOps, Docker, DigitalOcean...
Rezolve Limited
Amazon Web Services (AWS), Linux, Terraform, GitHub, Amazon EKS, Helm...
emonitor
Google Cloud, Google Cloud Platform (GCP), Google Kubernetes Engine (GKE)...

Experience

  • Linux - 6 years
  • Docker - 5 years
  • Amazon Web Services (AWS) - 4 years
  • Terraform - 4 years
  • Kubernetes - 4 years
  • Jenkins - 3 years
  • Google Cloud Platform (GCP) - 1 year

Availability

Full-time

Preferred Environment

Grafana, Prometheus, Docker, Terraform, Linux, Amazon Web Services (AWS), GitHub, Kubernetes, Flux, Helm

The most amazing...

...thing I've built was a highly scalable, highly available multicloud infrastructure with disaster recovery plans that received a PCI DSS certification.

Work Experience

DevOps Engineer

2022 - 2024
Novorésumé ApS
  • Migrated the whole infrastructure from DigitalOcean to AWS which increased reliability up to 99.999% and reduced infrastructure and maintenance costs by 30%.
  • Conducted migration from CircleCI to GitHub Actions. Reduced costs and sped and secured software delivery, allowing daily production deployments.
  • Implemented GitOps principles and IaC for the whole underlying infrastructure.
  • Implemented end-to-end observability for the whole platform, which reduced the time needed for troubleshooting and addressing.
Technologies: Kubernetes, Helm, Terraform, DevOps, Docker, DigitalOcean, Amazon Web Services (AWS), CircleCI, Node.js, Grafana, HashiCorp, Prometheus, Infrastructure as Code (IaC), NAT

DevOps Team Lead

2022 - 2023
Rezolve Limited
  • Planned, developed, and deployed HA/HS infrastructures in public cloud solutions.
  • Moved and translated all infrastructure for cloud providers to IaC format with Terraform (AWS, AliCloud, GCP, MongoDB Atlas). Created infrastructures similar throughout all cloud providers.
  • Managed six production Kubernetes clusters and their whole connecting infrastructures (multi-cloud).
Technologies: Amazon Web Services (AWS), Linux, Terraform, GitHub, Amazon EKS, Helm, Kubernetes, PCI DSS, Prometheus, Bash Script, Monitoring, Grafana, Alibaba Cloud, Rancher, Flux CD, Amazon RDS, AWS Lambda, AWS IAM, Amazon S3 (AWS S3), DevOps, AWS DevOps, DevOps Engineer, Cloud Architecture, Amazon EC2, Jira, CI/CD Pipelines, Architecture, Infrastructure as Code (IaC), NAT

Senior DevOps Engineer | System Architect

2021 - 2023
emonitor
  • Migrated fully from on-premise servers to GKE (cloud).
  • Performed Dockerization and set up for Kubernetes for all applications as part of on-premise to GKE migration.
  • Set up of full CI/CD process including feature-branches auto-deployment, auto-deployment with tests to dev/stg and production.
Technologies: Google Cloud, Google Cloud Platform (GCP), Google Kubernetes Engine (GKE), PCI DSS, Kubernetes, Helm, PostgreSQL, GitHub, Flux CD, Migration, Bash Script, Monitoring, Prometheus, Grafana, Terraform, Amazon S3 (AWS S3), DevOps, AWS DevOps, DevOps Engineer, Cloud Architecture, Google Cloud SQL, Google Cloud Storage, Jira, CI/CD Pipelines, SaaS, Architecture, Infrastructure as Code (IaC), NAT

DevOps Engineer | System Architect Consultant

2021 - 2023
Mediatoolkit
  • Contributed to the full migration from on-prem XEN to VMWare infrastructure in less than a year. Managed the new infrastructure via Terraform with VMWare + AWS.
  • Prepared and set up a hybrid cloud solution with on-prem VMWare with AWS.
  • Migrated 500GB-TB sized MongoDatabases and 100-500GB sized Redis databases with downtime in minutes to the new infrastructure.
Technologies: VMware, MongoDB, Redis, Rancher, Kubernetes, Elasticsearch, Prometheus, Flux, Grafana, GitHub, GitLab, Helm, MongoDB Atlas, Amazon Web Services (AWS), Bash Script, Monitoring, Terraform, GitLab CI/CD, Flux CD, Amazon RDS, AWS Lambda, AWS IAM, Amazon S3 (AWS S3), Migration, DevOps, AWS DevOps, DevOps Engineer, Cloud Architecture, Amazon EC2, Jira, CI/CD Pipelines, SaaS, Architecture, Infrastructure as Code (IaC), NAT

Senior DevOps Engineer | System Architect Consultant

2020 - 2022
Rezolve Limited
  • Planned, developed, and deployed HA/HS infrastructures in public cloud solutions.
  • Moved and translated all infrastructure for cloud providers to IaC format with Terraform (AWS, AliCloud, GCP, MongoDB Atlas). Created infrastructures similar throughout all cloud providers.
  • Managed old Kubernetes clusters and their transition to Helm.
  • Managed six production Kubernetes clusters and their whole connecting infrastructures (multi-cloud).
Technologies: Bash, Elasticsearch, Amazon Web Services (AWS), Flux, Linux, PostgreSQL, MongoDB Atlas, ELK (Elastic Stack), Grafana, Prometheus, Kubernetes, Terraform, Amazon EKS, Azure, Helm, GitHub, PCI DSS, Bash Script, Monitoring, Alibaba Cloud, Rancher, Flux CD, Amazon RDS, AWS Lambda, AWS IAM, Amazon S3 (AWS S3), Migration, DevOps, AWS DevOps, DevOps Engineer, Cloud Architecture, Amazon EC2, Jira, CI/CD Pipelines, Architecture, Infrastructure as Code (IaC), NAT

Infrastructure Engineer | Internal team

2020 - 2021
Toptal
  • Configured the CI/CD boilerplate infrastructure for a Terraform-managed infrastructure.
  • Upgraded 30+ Terraform repositories from TensorFlow version 0.12 to 0.13 and added best practices such as Dynamo DB locking.
  • Helped drive GitOps way for GKE deployments by providing experience with Flux in comparison to Argo.
Technologies: Kubernetes, Google Kubernetes Engine (GKE), Google Cloud Platform (GCP), Ansible, PostgreSQL, Atlantis, Jenkins, GitHub, Prometheus, Grafana, Amazon Web Services (AWS), Bash Script, Monitoring, Terraform, Helm, Google Cloud, AWS IAM, Amazon S3 (AWS S3), DevOps, AWS DevOps, DevOps Engineer, Jira, CI/CD Pipelines, Architecture, Infrastructure as Code (IaC), NAT

Senior DevOps Engineer

2019 - 2021
UniqCast
  • Redesigned and reorganized the entire development and deployment process.
  • Created CI/CD pipelines for front-end, back-end (Linux), and mobile applications (Android, iOS).
  • Designed and deployed a highly available and highly scalable monitoring, alerting, and logging cluster with ELK, Prometheus, and Grafana.
Technologies: ELK (Elastic Stack), NATS, Redis, PostgreSQL, Grafana, Prometheus, Ansible, Docker Swarm, Docker, Bitbucket, Jenkins, Amazon Web Services (AWS), Bash Script, Monitoring, Terraform, GitHub, Migration, DevOps, AWS DevOps, DevOps Engineer, Jira, CI/CD Pipelines, Architecture, Infrastructure as Code (IaC), NAT

Senior DevOps Engineer

2018 - 2019
Typeqast/Nanobit
  • Redesigned and reorganized the existing AWS infrastructure into valid industry standards with their parallel translation into IaC principles with Terraform.
  • Designed, deployed, and automated the infrastructure and entire development process through CI/CD with Jenkins and GitLab.
  • Designed and deployed HA and HS monitoring, alerting, and logging the cluster with ELK, Prometheus, and Grafana.
Technologies: Amazon Web Services (AWS), ELK (Elastic Stack), Riak, Redis, Docker, Grafana, Prometheus, GitLab, TeamCity, Ansible, Terraform, Bash Script, Monitoring, GitHub, Amazon S3 (AWS S3), AWS IAM, Amazon RDS, Migration, DevOps, AWS DevOps, DevOps Engineer, Cloud Architecture, Jira, CI/CD Pipelines, SaaS, Architecture, Infrastructure as Code (IaC), NAT

Senior Linux System Administrator

2018 - 2018
Altus Information Technology
  • Configured, deployed, and maintained HA and HS setups for various services (servers, opensource, and enterprise storage servers/clusters) and cloud services (IaaS) with KVM and VMware.
  • Deployed and maintained VMWare and KVM clusters, storage clusters Ceph/Storywise, highly resilient monitoring, and alerting clusters.
  • Ran the datacenter operations, oversaw the management, and performed project management.
Technologies: Grafana, Prometheus, Zenoss, OpenNebula, Corosync, Pacemaker, VMware, KVM, HAProxy, Ceph, Bash Script, Monitoring, Migration, DevOps, DevOps Engineer, Jira, CI/CD Pipelines, Architecture, NAT

Linux System Administrator

2017 - 2018
Crossvallia
  • Configured, deployed, and maintained production environments supporting various services—mostly high-performance high-throughput setups (highly scalable and fault-tolerant).
  • Troubleshot large systems/clusters in case of possible failures such as web clusters, MySQL clusters, and similar situations.
  • Managed database administration with MySQL/Percona 5.5/5.6 in standalone and MM configuration, PostgreSQL, and MongoDB.
  • Automated SSL renewal and installation across clusters.
Technologies: Puppet, Varnish, Elasticsearch, Redis, Memcached, PostgreSQL, MongoDB, MySQL, HAProxy, NGINX, Apache, Bash Script, Monitoring, Prometheus, Grafana, DevOps, DevOps Engineer, CI/CD Pipelines, NAT

L2 Support Technician | Shift Lead

2016 - 2017
Touch Support, Inc.
  • Managed shifts with 10-20 constantly changing people.
  • Offered Linux server support on CentOS and RHEL with the addition of technologies such as CloudLinux, cPanel, Plex, SolusVM, OnApp, and VMware vSphere.
  • Configured, deployed, and maintained customer servers and servers for shared hosting.
  • Worked with LAMP, LEMP, MySQL/MariaDB, and PostgreSQL. Managed virtualization with KVM, OpenVZ, XenServer, VMware ESXi, and Virtuozzo.
  • Developed custom Bash scripting for the various emerging issues of clients (PHP, Java).
Technologies: cPanel, SaltStack, MySQL, LEMP, LAMP, OnApp API, Virtuozzo, VMware ESXi, XenServer, OpenVZ, KVM, Linux, Bash Script, Monitoring, NAT

Level 1 Support Technician

2015 - 2016
Touch Support, Inc.
  • Recognized as the top agent for client reviews and resolved tickets, chats, and phone calls.
  • Implemented scripts for faster identification of known recurring issues.
  • Nominated for L2 technician and shift lead roles due to excellence in technical performance and knowledge.
Technologies: cPanel, SaltStack, MySQL, LEMP, LAMP, OnApp API, Virtuozzo, VMware ESXi, XenServer, OpenVZ, KVM, Linux, Bash Script, Monitoring

Experience

HA and HS Monitoring Infrastructure

Oversaw the monitoring, alerting, and logging of infrastructure, which was highly-available, highly-scalable, and deployable on any Docker swarm cluster with only a few modifications. Monitoring and alerting was based on Prometheus, Grafana, and various custom and opensource exporters. Logging consisted of ELK.

Jenkins CI/CD Pipelines

Developed CI/CD pipelines for testing, building, and deploying front-end and back-end applications supporting Android and iOS applications. Tested (unit tests, code-coverage), built, and deployed front-end (Angular) and back-end applications (Golang, Python, and Node.js) to Docker Swarm infrastructures. Tested and deployed mobile applications (Android and iOS) to the Google Store and Apple Store.

Education

2011 - 2015

Bachelor of Engineering (BE) Degree in Electrical Engineering, Department of Communication and Computer Technology

Zagreb University of Applied Sciences (TVZ) - Zagreb, Croatia

Certifications

JANUARY 2016 - JANUARY 2019

CCNA (Cisco Certified Network Associate)

Cisco

Skills

Libraries/APIs

OnApp API, Node.js

Tools

Grafana, Terraform, ELK (Elastic Stack), Docker Swarm, Jenkins, GitLab CI/CD, MongoDB Atlas, Helm, AWS IAM, Jira, SaltStack, Apache, NGINX, Varnish, Puppet, VMware, Pacemaker, Corosync, Zenoss, Ansible, TeamCity, GitLab, Bitbucket, GitHub, Amazon EKS, Google Kubernetes Engine (GKE), CircleCI, HashiCorp

Languages

Bash Script, Bash

Platforms

Linux, Docker, Kubernetes, Amazon Web Services (AWS), AWS Lambda, Amazon EC2, KVM, XenServer, LAMP, LEMP, cPanel, OpenNebula, Rancher, Azure, Google Cloud Platform (GCP), DigitalOcean

Frameworks

Flux

Paradigms

DevOps

Storage

Amazon S3 (AWS S3), Google Cloud SQL, Google Cloud Storage, PostgreSQL, Elasticsearch, Alibaba Cloud, MySQL, MongoDB, Memcached, Redis, Ceph, Riak, Google Cloud

Other

Prometheus, Monitoring, Architecture, Infrastructure as Code (IaC), Amazon RDS, AWS DevOps, DevOps Engineer, Cloud Architecture, CI/CD Pipelines, SaaS, NAT, OpenVZ, VMware ESXi, Virtuozzo, HAProxy, NATS, PCI DSS, Atlantis, Flux CD, Migration

Collaboration That Works

How to Work with Toptal

Toptal matches you directly with global industry experts from our network in hours—not weeks or months.

1

Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.
2

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.
3

Start your risk-free talent trial

Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.

Top talent is in high demand.

Start hiring