Nazrul I

System Engineer

Crystal Technology Ltd. • Full-time

Feb 2020 - Nov 2023 • 3 yrs 9 mos

Server Management – Linux (Ubuntu, CentOS, Debian), NGINX, Apache, DNS, SSL, UFW, and Fail2ban firewalls, Secure SSH. • Proficient in using Terraform to provision and manage cloud resources, including creating reusable modules for infrastructure components, ensuring consistency, and facilitating automated deployments. • Extensive experience with Amazon EKS (Elastic Kubernetes Service) for managing and orchestrating containerised applications, ensuring high availability, scalability, and security • Working with various AWS services like VPC, EC2, EBS, RDS, IAM, S3, Route 53, Redis, ElastiCache, CloudFront, SES, EKS, ECS, ECR, OpenVPN, site-to-site VPN, Load Balancer, autoscaling group, WAF, ElastiCache, SQS, SNS, and Amplify to architect, deploy, and manage scalable and resilient cloud infrastructures. • Deployed the PHP, Laravel, Django, Flask, Odoo 18, WordPress, React and Node.js applications on the Kubernetes infrastructure. • Having good knowledge of containerisation. Managing Docker containers, Docker image management, inspecting containers, Docker networking, Docker volumes, creating Dockerfiles, using Docker Compose, and a private Docker registry. • Concept: Kubernetes cluster architecture, pod, deployment, replica set, daemon set, Kubernetes services, Ingress, Gateway API, NodePort, ClusterIP, Secret, Persistent volume, LoadBalancer, node selector, node affinity, taint, and toleration. • Designed and implemented auto-scaling solutions for AWS resources using features like AWS Auto Scaling, ensuring that Applications can handle varying workloads efficiently and cost-effectively • Automated DevOps workflows using Bash or Python scripts. • Improved security, IAM roles, and network configurations. • Configured Cloudflare to mitigate DDoS attacks (WAF, L7 rules, firewall, bot filtering, rate limiting).