--- title: "Arnab Adhikary (@terena) | Hashnode" description: "DevOps Engineer at Cognizant. Read the latest articles by Arnab Adhikary on Hashnode." url: "https://hashnode.com/@terena" --- @terena # Arnab Adhikary @terena · Mumbai · Joined April 2026 DevOps Engineer at Cognizant ### [Day 28: Observability - Mastering CloudWatch Logs, Metrics, and Alarms 👁️](https://aws-arnab.hashnode.dev/day-28-observability-mastering-cloudwatch-logs-metrics-and-alarms?utm_source=hashnode&utm_medium=feed) Welcome to Day 28 of our 30-Day AWS DevOps Series! We have entered the final stretch: Phase 5 (Observability, Security & Best Practices). Over the last four weeks, you've built pipelines, deployed con 4 min read · [aws-arnab.hashnode.dev](https://aws-arnab.hashnode.dev/day-28-observability-mastering-cloudwatch-logs-metrics-and-alarms?utm_source=hashnode&utm_medium=feed) [May 28](https://hashnode.com/posts/day-28-observability-mastering-cloudwatch-logs-metrics-and-alarms/6a18b8db78258754833db049) ### [Day 27: Centralized Logging — Mastering Distributed Logs with Grafana Loki & Promtail 🪵](https://aws-arnab.hashnode.dev/day-27-centralized-logging-mastering-distributed-logs-with-grafana-loki-promtail?utm_source=hashnode&utm_medium=feed) Yesterday, we shined a light on our cluster metrics using Prometheus and Grafana. We learned if something is broken. But when an API throws a 500 Internal Server Error, metrics won't tell you the exac 4 min read · [aws-arnab.hashnode.dev](https://aws-arnab.hashnode.dev/day-27-centralized-logging-mastering-distributed-logs-with-grafana-loki-promtail?utm_source=hashnode&utm_medium=feed) [2](https://hashnode.com/posts/day-27-centralized-logging-mastering-distributed-logs-with-grafana-loki-promtail/6a0f8437d8e265f60d651c2f) [May 21](https://hashnode.com/posts/day-27-centralized-logging-mastering-distributed-logs-with-grafana-loki-promtail/6a0f8437d8e265f60d651c2f) ### [Day 26: Shines a Light in the Dark — Cloud-Native Observability with Prometheus & Grafana 📊](https://aws-arnab.hashnode.dev/shines-a-light-in-the-dark-cloud-native-observability-with-prometheus-grafana?utm_source=hashnode&utm_medium=feed) In a monolithic application, tracking down a bug usually means logging into one server and running tail -f var/log/app.log. But in a Kubernetes cluster with hundreds of ephemeral pods constantly movin 4 min read · [aws-arnab.hashnode.dev](https://aws-arnab.hashnode.dev/shines-a-light-in-the-dark-cloud-native-observability-with-prometheus-grafana?utm_source=hashnode&utm_medium=feed) [May 17](https://hashnode.com/posts/shines-a-light-in-the-dark-cloud-native-observability-with-prometheus-grafana/6a0a2e153104e2aff0de653f) ### [Day 25: The GitOps Revolution — Continuous Delivery with ArgoCD 🐙](https://aws-arnab.hashnode.dev/the-gitops-revolution-continuous-delivery-with-argocd?utm_source=hashnode&utm_medium=feed) Yesterday, we learned how to package our Kubernetes applications using Helm. But how do we actually deploy and update them automatically when our code changes? Enter GitOps and ArgoCD — the modern sta 4 min read · [aws-arnab.hashnode.dev](https://aws-arnab.hashnode.dev/the-gitops-revolution-continuous-delivery-with-argocd?utm_source=hashnode&utm_medium=feed) [May 16](https://hashnode.com/posts/the-gitops-revolution-continuous-delivery-with-argocd/6a08e02c74b18db68628fa5a) ### [Day 23: The Memory of the Cluster — Mastering Kubernetes Storage 💾](https://aws-arnab.hashnode.dev/day-23-the-memory-of-the-cluster-mastering-kubernetes-storage?utm_source=hashnode&utm_medium=feed) By default, Kubernetes Pods are "stateless." If a Pod dies, any data saved inside its container is lost forever. For databases or file uploads, this is a nightmare. Today, we solve this by diving into 3 min read · [aws-arnab.hashnode.dev](https://aws-arnab.hashnode.dev/day-23-the-memory-of-the-cluster-mastering-kubernetes-storage?utm_source=hashnode&utm_medium=feed) [May 10](https://hashnode.com/posts/day-23-the-memory-of-the-cluster-mastering-kubernetes-storage/6a00ff97e3eebc2e20d32afc)