Senior Platform Engineer System Design Playbook | Senior DevOps Technical Interview Training

🛠️ Senior Platform Engineer System Design Playbook | Senior DevOps / Platform Engineer Technical Interview Training What actually happens inside the Linux kernel and cloud infrastructure when a core database vanishes without leaving an application error log? This playbook details over a decade of battle-tested platform engineering experience in building and maintaining autonomous data centers. Learn how low-level operating system mechanics, container orchestrators, and automated CI/CD pipelines intersect with system design trade-offs. 📌 Key Topics Covered: • Low-Level OS & Kernel: TCP SYN backlog queues vs. accept queues, memory overcommit, Linux OOM Killer, dmesg logs, and SIGKILL (Exit Code 137) • Networking & Load Balancing: AWS ALB (Layer 7 HTTP proxy) vs. NLB (Layer 4 static IP performance) • Kubernetes Architecture: Stacked vs. External etcd quorum risks, Pod Anti-Affinity across Availability Zones, debugging with `kubectl logs --previous`, and stuck rollout diagnoses • Enterprise Security & Multi-Tenancy: ResourceQuotas, Default-Deny NetworkPolicies (L3/L4), Istio Service Mesh (L7 mTLS), Base64 secret myths, External Secrets Operator, Trivy, Harbor, Cosign, Falco (eBPF), Wazuh CIS benchmarks, and Cert-Manager • Infrastructure Automation: Terraform remote state locking (S3 + DynamoDB force unlock safety), DAG topological sorting, and multi-AZ private VPC isolation • Data Pipeline Engineering: Kafka Consumer Groups, lag metrics, ISR under-replicated partitions, key salting, and delivery semantics (At-Most-Once, At-Least-Once, Exactly-Once) • Search Engine Mechanics: Elasticsearch primary shard routing modulo math, oversharding hazards, cluster health colors (Green, Yellow, Red), and 32GB JVM heap rules • Delivery Pipelines & GitOps: Jenkins dynamic Kubernetes build runners, Blue-Green vs. Canary deployments, Argo CD reconciliation loops, and overlapping cron job race conditions #PlatformEngineering #Kubernetes #SystemDesign #DevOps #GitOps #Terraform #SoftwareArchitecture #Linux