Backend Development Testing, DevOps and Deployment Syllabus

In Kubernetes, what is a Pod?

The smallest deployable unit in Kubernetes: one or more tightly coupled containers that share the same network namespace (IP/port space) and storage volumes, and are scheduled together on a node.

What is the role of a Kubernetes Deployment?

A controller that manages a ReplicaSet to maintain a desired number of Pod replicas and enables declarative updates, rolling updates, and rollbacks of the application's Pods.

What is a Kubernetes Service and why is it needed?

A stable network abstraction (fixed virtual IP/DNS name) that load-balances traffic to a dynamic set of Pods selected by labels, decoupling clients from ephemeral Pod IPs.

Distinguish the Kubernetes Service types ClusterIP, NodePort, and LoadBalancer.

ClusterIP: internal-only virtual IP (default). NodePort: exposes the service on a static port on every node. LoadBalancer: provisions an external cloud load balancer routing to the service.

What is the Kubernetes control plane component responsible for scheduling Pods to nodes?

The kube-scheduler, which assigns unscheduled Pods to suitable nodes based on resource requests, constraints, affinity/anti-affinity, and taints/tolerations.

What does Continuous Integration (CI) mean?

The practice of developers frequently merging code into a shared mainline, where each integration triggers an automated build and test run to detect integration problems quickly.

What is the distinction between Continuous Delivery and Continuous Deployment?

Continuous Delivery keeps every change automatically built, tested, and release-ready, but the final push to production is a manual decision. Continuous Deployment goes further, automatically releasing every passing change to production with no manual gate.

What is a CI/CD pipeline?

An automated sequence of stages (e.g., build, test, security scan, package, deploy) that code changes pass through from commit to production, providing fast feedback and repeatable releases.

Name four common CI/CD pipeline tools.

Jenkins, GitHub Actions, GitLab CI/CD, CircleCI, Travis CI, Argo CD, and Azure DevOps Pipelines are common examples.

In GitHub Actions, what are 'workflows', 'jobs', and 'steps'?

A workflow is an automated process defined in YAML triggered by events; it contains one or more jobs (units running on a runner, possibly in parallel); each job contains steps (individual commands or reusable actions run sequentially).

What is a blue-green deployment strategy?

Two identical production environments ('blue' live, 'green' idle) exist; the new version is deployed to green, tested, then traffic is switched from blue to green all at once. Rollback is instant by switching back.

What is a canary deployment strategy?

The new version is released to a small subset of users/servers first; if metrics stay healthy, traffic is gradually increased until 100%, limiting the blast radius of a bad release.

What is a rolling deployment?

Instances running the old version are incrementally replaced by the new version a few at a time, so the service stays available throughout with no full second environment required.

How does a canary deployment differ from blue-green?

Blue-green switches all traffic at once between two full environments; canary shifts traffic gradually to a small subset first and ramps up. Canary uses fewer extra resources but exposes some users to the new version during rollout.

Name the three major public cloud providers and their common shorthand names.

Amazon Web Services (AWS), Google Cloud Platform (GCP), and Microsoft Azure.

What are the equivalent core virtual-machine compute services on AWS, GCP, and Azure?

AWS: EC2 (Elastic Compute Cloud); GCP: Compute Engine; Azure: Virtual Machines.

What are the equivalent object storage services on AWS, GCP, and Azure?

AWS: S3 (Simple Storage Service); GCP: Cloud Storage; Azure: Blob Storage.

Contrast object storage, block storage, and file storage.

Object storage keeps data as objects with metadata in a flat namespace (e.g., S3), ideal for unstructured data. Block storage splits data into fixed blocks attached to VMs like a disk (e.g., EBS). File storage exposes a hierarchical shared filesystem (e.g., NFS/EFS).

In cloud networking, what is a VPC?

A Virtual Private Cloud: a logically isolated virtual network within a cloud provider where you define IP ranges, subnets, route tables, and gateways to control connectivity and security.

What is the difference between a public subnet and a private subnet in a VPC?

A public subnet has a route to an internet gateway so its resources can be reached from/reach the internet directly; a private subnet has no direct internet route, typically using a NAT gateway for outbound-only access.

What is serverless computing / Functions as a Service (FaaS)?

A model where you deploy individual functions that the cloud provider runs on demand, automatically scaling and billing only for actual execution time; you manage no servers. Examples: AWS Lambda, Google Cloud Functions, Azure Functions.

What is a 'cold start' in serverless functions?

The added latency incurred when a function is invoked and no warm execution environment exists, so the platform must provision a container, load the runtime, and initialize code before handling the request.

What are two common limitations to remember about serverless functions?

They have maximum execution timeouts (e.g., AWS Lambda's 15-minute limit) and are stateless between invocations, plus cold-start latency and constrained memory/compute per invocation.

What is Infrastructure as Code (IaC)?

Managing and provisioning infrastructure through machine-readable definition files (code) rather than manual processes, enabling versioned, repeatable, automated, and reviewable infrastructure changes.

What is the difference between declarative and imperative IaC?

Declarative IaC specifies the desired end state and the tool figures out how to reach it (e.g., Terraform). Imperative IaC specifies the explicit sequence of commands to execute to reach the state (e.g., a shell/Ansible procedural script).

What is Terraform, and what is idempotency in IaC?

Terraform is a declarative IaC tool using HCL to provision cloud resources. Idempotency means applying the same configuration repeatedly yields the same final state without unintended repeated changes.

What are structured logs, and why are they preferred over plain-text logs?

Structured logs record events as machine-parseable key-value data (typically JSON) rather than free-form text, making them far easier to search, filter, aggregate, and analyze programmatically.

What do the standard log severity levels DEBUG, INFO, WARN, and ERROR indicate?

DEBUG: fine-grained diagnostic detail for developers; INFO: normal operational events; WARN: unexpected but recoverable situations that may need attention; ERROR: failures where an operation could not complete.

What are the 'three pillars of observability'?

Logs (discrete timestamped event records), metrics (numeric measurements aggregated over time), and traces (end-to-end records of a request's path across services).

Name common tools for collecting metrics and building dashboards, and define a key metric type.

Prometheus (metrics collection/storage) with Grafana (dashboards) is a common pairing. A counter is a cumulative metric that only increases (e.g., total requests); a gauge is a value that can go up or down (e.g., current memory usage).