1. IaaS (Infrastructure as a Service)
IaaS provides raw infrastructure:
- Virtual machines
- Storage
- Networking
We manage OS, runtime, middleware, scaling, security patches.
GCP IaaS Services
| Service | Purpose |
| Compute Engine | Virtual Machines |
| Persistent Disk | Block storage |
| Cloud Storage | Object storage |
| VPC | Virtual networking |
| Load Balancer | Traffic distribution |
Responsibility Model
| Layer | Who manage |
| Physical DC, Hardware | |
| VM | We |
| OS | We |
| Runtime | We |
| App | We |
Example
Hosting a Custom Node.js app on VM
- We install Node.js
- Configure firewall
- Handle scaling
- Patch OS
When to use IaaS
- Legacy application
- Full OS controllneeded
- Custom networking or drivers
- Lift-and-shift migration
2. PaaS (Platform as a Service)
Paas provides a ready platform where we only focus on code, not infrastructure.
GCP manages:
- OS
- Runtime
- Scaling
- Load balancing
GCP PaaS Services
| Service | Use case |
| App Engine | Web & API apps |
| Cloud Run | Containerized apps |
| Cloud Functions | Event-driven code |
Responsibility Model
| Layer | Who manages |
| Infrastructure | |
| OS | |
| Runtime | |
| App code | We |
Example
Deploying a REST API on App Engine:
- Push code
- Auto scaling
- No server management
When to use PaaS
- Rapid development
- Microservices
- Startups
- Minimal ops team
3. SaaS (Software as a Serviec)
Fully managed software products. We just use the software, nothing to manage.
Goolge Saas Example:
| Products | Purpose |
| Gmail | |
| Google Drive | Storage |
| Google Docs | Office tools |
| BigQuery | Analytics |
Responsibility Model
| Layer | Who manages |
| Everthing |
Example
Using BigQuery:
- No servers
- No DB tuning
- Pay per query
When to use SaaS
- Business productivity
- Analytics
- Collaboration tools
4. Managed Services in GCP
GCP manages infrastructure and operations, but you control configuration and data.
Think of it as PaaS for specific services.
GCP managed services example
| Service | Type |
| Cloud SQL | Managed relational DB |
| Cloud Firestore | NoSQL DB |
| Pub/Sub | Messaging |
| BigQuery | Data warehouse |
| Memorystore | Redis/Memcached |
What GCP Manages
- Scaling
- Backups
- Patching
- High availability
What We Manage
- Schema
- Queries
- Access control
- Data
Example
Using Cloud SQL (PostgreSQL):
- No VM setup
- Automatic backups
- Auto failover
5. Managed Resources in GCP
Resources where Google manages lifecycle & health, but you still provision and configure them.
| Resource | Description |
| Managed Instance Groups(MIG) | Auto-scaled VM groups |
| GKE Nodes | Managed worker nodes |
| Load Balancer | Fully managed traffic control |
| Cloud DNS | Managed DNS |
Example
Managed Instance Group
- We define template
- Google handles
- VM recreations
- Health checks
- Auto scaling
Difference from Managed Services
| Managed Resources | Managed Services |
| Infra components | End services |
| We manage app | We manage data/config |
| VM-level | Service-level |
6. Serverless Computing
We never see servers.
- No provisioning
- No scaling
- Pay only for usage
GCP Serverless Services
| Service | Purpose |
| Cloud Functions | Event-Driven |
| Cloud Run | Containers |
| App Engine | Web apps |
Characteristics
- Auto scaling(0 -> Millions)
- Stateless
- Event-driven
- Short-lived execution
Example
Cloud Function triggered by:
- Pub/Sub
- HTTP request
- Cloud Storage upload
When to use Serverless
- Event processing
- APIs
- Background jobs
- Low or unpredictable traffic
7. Google Cloud Networking
Core Networking Components
1. VPC(Virtual Private Cloud)
- Global private network
- Subnets are regional
- Software-defined networking
2. Subnets
- IP ranges
- Region-specific
- Private or public
3. Firewall Rules
- Allow/deny traffic
- Stateful
- Applied at VPC level
4. Load Balancing
| Type | |
| HTTP(s) | Web traffic |
| TCP/UDP | Low-level-traffic |
| Internal LB | Private services |
5. Cloud NAT
- Outbound internet access
- No public IP on VM
6. VPN & Interconnect
| Service | Purpose |
| Cloud VPN | Secure tunnel |
| Interconnect | Dedicated private link |
7. DNS
- Cloud DNS
- Public & Private Zones
Quick Comparison
| Model | Control | GCP Examples |
| IaaS | Full | Compute Engine |
| PaaS | Medium | App Engine |
| SaaS | None | Gmail |
| Managed Service | Config/Data | Cloud SQL |
| Managed Resource | Infra-level | MIC |
| Serverless | Code Only | Cloud Functions |