Software-Engineering

Software Engineering Core Learning Roadmap

For every topic, always cover:

• What it is
• Why we need it
• What existed before it
• How it works (end-to-end flow)
• Types / versions
• Problems it solves
• Use cases
• Pros and cons
• Hands-on experiment
• Common mistakes
• Interview and production perspective

---

Chapter 1: Computer Fundamentals

1. Memory

• RAM vs ROM
• Virtual memory
• Stack vs Heap
• Paging and segmentation
• Garbage collection
• Memory leaks

2. CPU

• CPU architecture
• Cores vs threads
• Clock cycle
• Context switching
• User mode vs kernel mode

3. Process

• What is a process
• Process lifecycle
• Inter-process communication (IPC)

3.1 Multiprocessing

• Fork vs spawn
• Process isolation

3.2 Shared Memory Processes

• Shared memory models
• Race conditions

4. Threads

• Thread vs process
• Thread lifecycle

4.1 Multithreading

• Thread safety
• Mutex, locks, semaphores
• Deadlock and starvation

5. Cache

• CPU cache (L1, L2, L3)
• Cache lines
• Cache coherence
• Cache misses

---

Chapter 2: Networking and Internet

1. Network and Internet Basics

• What is a network
• How the internet works

1.1 Router and Switch

• Routing vs switching
• NAT
• Load balancing basics

1.2 WiFi and ISP Working

• ISP role
• Bandwidth vs latency

2. OSI Model

• All 7 layers
• Mapping protocols to layers

3. IP, MAC, and Ports

• IPv4 vs IPv6
• MAC address
• Ports and port ranges

3.1 Data Packets

• Packet structure
• MTU
• Fragmentation

4. Protocols

4.1 TCP and UDP

• TCP handshake
• Reliability
• Congestion control

4.2 HTTP and HTTPS

• Request-response cycle
• Status codes
• Headers
• SSL
• TLS

4.3 SSH

• SSH handshake
• Public-private key authentication

4.4 WebSockets

• Persistent connections
• Real-time communication

5. Firewall

• Network firewall
• Application firewall

6. Proxy

• Forward proxy
• Reverse proxy
• CDN basics

7. Data Encryption

7.1 Symmetric Encryption

7.2 Asymmetric Encryption

7.3 Hashing

---

Chapter 3: Core Backend Concepts

1. API

• What is an API

1.1 API Design

• REST principles
• Pagination
• Idempotency

1.2 API Security

• Rate limiting
• CORS
• API keys

1.3 API Testing

• Unit tests
• Integration tests

1.4 API Types

• REST
• SOAP
• GraphQL
• gRPC

1.5 WebSockets and Webhooks

2. Authentication and Authorization

3. JWT

• Token structure
• Access and refresh tokens
• Security risks

4. Sessions and Storage

• Sessions
• Cookies
• LocalStorage
• SessionStorage

5. Caching

• Why caching
• Cache invalidation
• LRU and LFU

6. Docker

• Containers vs virtual machines
• Docker images
• Dockerfile
• Docker Compose

7. Git and GitHub

• Git internals
• Branching strategy
• Merge vs rebase

8. Logging and Monitoring

• Logs
• Metrics
• Tracing

9. Sync and Async Systems

• Blocking vs non-blocking

Message Brokers

• Redis
• Kafka
• RabbitMQ

10. Testing

• Unit testing
• Automation testing
• Test pyramid

11. Service Workers

• Offline support
• Caching strategies

12. Code Quality

• Clean code
• SOLID principles
• Linting
• Code reviews

---

Chapter 4: Database Internals

1. How Databases Work with Disk

• Disk I/O
• Write-ahead logging
• B-tree basics

2. CAP Theorem

3. ACID Properties

4. PostgreSQL vs MongoDB

• Differences
• Use cases

5. Database Internals

• Buffers
• Pages
• Isolation levels
• Transactions
• Sharding
• Replication

6. Database Monitoring

• Slow queries
• Locks
• Performance bottlenecks

7. Table Design

• Normalization
• Denormalization

8. Indexing

• B-tree indexes
• Hash indexes
• Composite indexes

9. Joins

• Inner join
• Left join
• Right join
• Full join

10. Database pooling

Chapter 5: Advanced

1. Load balancing
2. Horizontal vs vertical scaling
3. Distributed systems basics
4. Event-driven architecture
5. Backpressure
6. Rate limiting algorithms
7. Circuit breaker pattern
8. Database connection pooling
9. Observability