System design · Integration · Cloud · Security · GenAI
Tech concepts: the learning roadmap
Your list, put in a logical order (each section builds on the previous one) and extended with the concepts that usually come up alongside it. Every concept has a one-line definition, how it works, a visual, points to remember, and many have a ready-to-copy LinkedIn post idea. Every technical concept also has a .NET 10 "How to implement it" box listing the libraries to use, with a short C# snippet where it helps.
🧭 The learning path
From the basics, through building blocks and architecture, to operations, AI, and putting it all together.
01 Foundations
→
02 Protocols
→
03 Scalability & Reliability
→
04 Distributed Systems
→
05 Caching
06 Databases & Data
→
07 Data Governance
→
08 API Design
→
09 APIM
→
10 Integration & Messaging
11 Architecture Patterns
→
12 Architecture Docs
→
13 Architecture Practice
→
14 Security & IAM
→
15 DevOps & Observability
16 Cloud Cheat Sheet
→
17 RAG & GenAI
→
18 Agentic AI
→
19 Banking & Payments
→
20 E2E Playbook
21 Case Studies
→
22 .NET Use Cases
→
23 .NET Deep Dive
→
24 Design & Coding
25 Interview Readiness
→
26 Solution Architect Questions
→
27 Solution Designer Questions
→
28 Engineering Manager Questions
→
29 Role Foundations
Green items in the cards below (marked ＋) are concepts added to your original list to fill gaps in system design, integration and end-to-end coverage.
SECTION 01
Foundations
- Process vs Thread
- ＋ Concurrency vs Parallelism
- Sync vs Async
- ＋ Latency vs Throughput
- ＋ Back-of-the-envelope numbers
- ＋ Races, locks & deadlocks
- ＋ Concurrency models
- ＋ OS essentials
- ＋ Memory & storage hierarchy
- ＋ Data structures in systems
- ＋ Typing a URL
- ＋ Building blocks
- ＋ Requirements & NFRs
- ＋ Scaling & partitioning
- ＋ Data fundamentals
- ＋ Communication patterns
- ＋ Reliability fundamentals
- ＋ Coordination primitives
- ＋ Security & observability baseline
SECTION 02
Networking & Communication Protocols
- ＋ OSI / TCP-IP layers
- ＋ TCP vs UDP
- ＋ HTTP/1.1 vs 2 vs 3
- ＋ DNS
- Communication protocols
- ＋ Polling vs WebSocket vs SSE vs Webhook
- ＋ Data formats
SECTION 03
Scalability & Reliability
- Vertical vs Horizontal
- ＋ Stateless vs Stateful
- Load balancing
- ＋ Consistent hashing
- Fault tolerance
- ＋ Resilience patterns
- ＋ Availability (HA & nines)
- ＋ Performance
- ＋ Capacity planning & FinOps
- ＋ SLA / SLO / SLI
- CAP
- ＋ PACELC & consistency
- ＋ Disaster recovery (RPO/RTO)
- ＋ Cells & multi-region active-active
SECTION 04
Distributed Systems
- ＋ Why distributed is hard
- ＋ Replication models
- ＋ Quorum (N, W, R)
- ＋ Consensus & leader election
- ＋ Distributed locks
- ＋ 2PC vs Saga
- ＋ Time & ordering
SECTION 05
Caching
- ＋ Where to cache
- Caching strategies
- Expiration strategies
- ＋ Eviction policies
- ＋ Stampede, penetration, avalanche
- ＋ CDN
- ＋ Redis vs Memcached
- ＋ Probabilistic data structures
SECTION 06
Databases & Data
- ＋ SQL vs NoSQL
- ＋ ACID vs BASE
- ＋ Indexing
- ＋ Unique ID generation
- ＋ Search systems
- ＋ Geospatial indexing
- Database scaling
- ＋ Block vs file vs object storage
- Backup strategies
- Data migration strategies
- ETL vs ELT
- ＋ CDC
- ＋ Warehouse vs Lake vs Lakehouse
SECTION 07
Data Governance & Privacy
- ＋ Governance basics
- ＋ Data classification
- ＋ Privacy & PII
- ＋ Residency & sovereignty
- ＋ Retention & deletion
- ＋ Quality & lineage
- ＋ Master data (MDM)
- ＋ Data contracts & mesh
SECTION 08
API Design, Security & Performance
- API architecture patterns
- ＋ REST design best practices
- API authentication & authorization
- ＋ OAuth 2.0 / OIDC / JWT deep dive
- API performance
- Rate limit algorithms
- ＋ Idempotency
- ＋ GraphQL: when and how
SECTION 09
API Management (APIM)
- What APIM is
- Core building blocks
- Policies & pipeline
- Security in APIM
- Versions vs revisions
- API lifecycle & APIOps
- Monitoring & analytics
- Gateway patterns & AI gateway
- ＋ Gateway vs LB vs Mesh vs ESB
SECTION 10
Integration & Messaging
- Real-time vs Near-RT vs Batch
- ＋ Integration styles & approaches
- Queue vs Event-driven
- ＋ Delivery guarantees
- ＋ Back-pressure & flow control
- ＋ Messaging patterns (EIP)
- ＋ Orchestration vs Choreography
- ＋ Batch & file integration
- ＋ Event streaming & Kafka
SECTION 11
Architecture Patterns
- Architecture patterns (styles)
- ＋ Hexagonal / Clean / Onion
- ＋ Monolith vs Microservices
- Microservice patterns
- ＋ Microservice API patterns
- ＋ Saga
- ＋ CQRS & Event Sourcing
- ＋ Strangler Fig
- ＋ Sidecar & Service Mesh
- ＋ DDD essentials
- ＋ Event storming
- Serverless architecture
- ＋ 12-Factor App
- ＋ Multi-tenancy patterns
SECTION 12
Architecture Documents & Governance
- Document lifecycle
- ACD
- AIA
- SO
- ＋ HLD
- LLD
- ADR
- SOP
- ＋ NFRs
- ＋ C4 model
- ＋ Threat model
- ＋ Runbook vs SOP vs Playbook
- ＋ TOGAF & Well-Architected
- ＋ Soft skills: trade-offs & stakeholders
- ＋ Build vs buy, tech debt & governance
SECTION 13
Architecture Practice
- ＋ EA toolkit
- ＋ Quality attributes & trade-offs
- ＋ Cloud migration (7 Rs)
- ＋ Legacy & mainframe modernisation
- ＋ Team & org architecture
- ＋ API & event evolution
- ＋ Front-end & edge
- ＋ Reference architectures & katas
- ＋ Platform engineering & IDPs
SECTION 14
Security, IAM & Cryptography
- ＋ AuthN vs AuthZ
- IAM
- ＋ SSO: SAML vs OAuth vs OIDC
- Symmetric vs Asymmetric keys
- ＋ Hashing vs Encryption vs Encoding vs Tokenisation
- ＋ TLS, mTLS & PKI
- ＋ Secrets & key management
- ＋ Zero Trust
- ＋ OWASP API Top 10
- ＋ DevSecOps & supply chain
SECTION 15
DevOps, Deployment & Observability
- ＋ CI/CD
- ＋ Branching & code review
- ＋ Testing strategy
- ＋ Versioning & releases
- Deployment strategies
- ＋ Feature flags
- ＋ IaC & GitOps
- ＋ Containers & Kubernetes
- ＋ Observability
- ＋ Logging
- ＋ Metrics
- ＋ Alerting
- ＋ Incident management
- ＋ SRE practices
- ＋ DORA metrics
- ＋ Chaos & game days
SECTION 16 · REFERENCE
Cloud Cheat Sheet: Azure vs AWS vs GCP
- ＋ How to read this
- ＋ Compute
- ＋ Containers & Kubernetes
- ＋ Storage
- ＋ Networking & edge
- ＋ Databases
- ＋ Analytics & data integration
- ＋ Messaging & events
- ＋ AI & ML
- ＋ Identity & security
- ＋ Monitoring & IaC
- ＋ DevOps
- ＋ Choosing a cloud
- ＋ FinOps & cost
SECTION 17
RAG & GenAI
- ＋ LLM basics
- ＋ Prompt engineering
- ＋ Prompting vs RAG vs fine-tuning
- RAG overview
- Chunking
- Embedding
- Vector search
- Top-K retrieval
- Metadata filtering
- Hybrid search
- Ranking & re-ranking
- Query transformation
- RAG Fusion
- RAG evaluation
- ＋ Advanced RAG patterns
- ＋ Failure points & fixes
- ＋ LLMOps & GenAI platform
- ＋ Responsible AI
SECTION 18
Agentic AI
- What is Agentic AI
- ＋ Workflows vs Agents
- ＋ Agent loop (ReAct)
- ＋ Tools & function calling
- ＋ Memory & planning
- ＋ Multi-agent patterns
- ＋ MCP & A2A
- ＋ Guardrails & HITL
- ＋ Evaluation & AgentOps
SECTION 19
Banking & Payments Domain
- ＋ Payments landscape (AU)
- ＋ NPP, Osko & PayID
- ＋ PayTo
- ＋ BECS / Direct Entry
- ＋ Cards
- ＋ Cross-border & SWIFT
- ＋ Open Banking & CDR
- ＋ Regulation & resilience
- ＋ Core banking & ledger
SECTION 20 · CAPSTONE
End-to-End System Design Playbook
- ＋ End-to-end request journey
- ＋ Interview framework
- ＋ How to answer "X vs Y"
- ＋ Trade-off cheat sheet
- ＋ Worked example
- ＋ Design review checklist
SECTION 21 · PRACTICE
Design Case Studies
- ＋ URL shortener
- ＋ Distributed rate limiter
- ＋ Chat / messaging app
- ＋ Notification service
- ＋ News feed / timeline
- ＋ Video streaming platform
- ＋ Payment ledger
SECTION 22 · PRACTICE
Top 10 System Design Use Cases in .NET
- ＋ Flash sale without overselling
- ＋ Booking with temporary holds
- ＋ Search autocomplete
- ＋ Proximity service
- ＋ Large file upload
- ＋ Distributed job scheduler
- ＋ Web crawler
- ＋ Real-time fraud detection
- ＋ Customer onboarding (KYC) workflow
- ＋ Enterprise RAG assistant
SECTION 23
.NET Engineering Deep Dive
- ＋ CLR, JIT & memory
- ＋ Garbage collection
- ＋ async/await internals
- ＋ Thread pool
- ＋ DI lifetimes
- ＋ Request pipeline
- ＋ HttpClient
- ＋ EF Core performance
- ＋ High-performance .NET
- ＋ Orleans actors
- ＋ Framework → modern .NET
- ＋ Writing middleware
- ＋ ASP.NET Core Web API
- ＋ MVC, Razor Pages & Blazor
- ＋ AuthN & AuthZ
- ＋ EF Core essentials
- ＋ Config, options & hosting
- ＋ WCF & migration
- ＋ Modern C# & .NET
SECTION 24
Software Design & Coding Fundamentals
- ＋ Design principles
- ＋ SOLID
- ＋ Creational patterns
- ＋ Structural patterns
- ＋ Behavioural patterns
- ＋ Anti-patterns & smells
- ＋ Clean code & review
- ＋ Big-O & collections
- ＋ Coding interview patterns
SECTION 25 · INTERVIEW
Interview Readiness
- ＋ How the loop works
- ＋ STAR(R) method
- ＋ Behavioural bank
- ＋ Technical deep dive
- ＋ Architecture katas
- ＋ Presenting a case
- ＋ Questions & checklist
SECTION 26 · INTERVIEW
Solution Architect Behavioural Questions (STAR)
- ＋ How to use these answers
- ＋ Strategy & roadmaps
- ＋ Governance & standards
- ＋ Cloud, resilience & vendors
- ＋ Integration, API & data
- ＋ AI & GenAI strategy
- ＋ Delivery & stakeholders
- ＋ Risk, regulation & ethics
SECTION 27 · INTERVIEW
Solution Designer Behavioural Questions (STAR)
- ＋ How to use these answers
- ＋ Requirements & options
- ＋ Design decisions
- ＋ Cloud & platform
- ＋ Patterns & trade-offs
- ＋ API design
- ＋ System integration
- ＋ AI & GenAI
- ＋ Security, data & NFRs
- ＋ Implementation & quality
- ＋ Delivery & handover
SECTION 28 · INTERVIEW
Engineering Manager Behavioural Questions (STAR)
- ＋ How to use these answers
- ＋ Technical direction
- ＋ Cloud, reliability & cost
- ＋ Engineering practices
- ＋ API & integration delivery
- ＋ AI & GenAI adoption
- ＋ Hiring, performance & growth
- ＋ Team leadership & conflict
- ＋ Onboarding & mentoring
- ＋ Delivery under pressure
- ＋ Support & incidents
- ＋ Culture & hard decisions
SECTION 29 · INTERVIEW
Role Foundations: Architect, Designer, Manager, Principal Engineer
- ＋ Roles at a glance
- ＋ Solution architect
- ＋ Solution designer
- ＋ Engineering Manager
- ＋ Principal Engineer
- ＋ Roles working together
📣 LinkedIn content kit
A simple, repeatable format for short, scannable posts. Every section has ready drafts in the blue "LinkedIn post idea" boxes (click Copy).
1. Hook (line 1)
A question, a myth or an analogy. "Queue vs Event in one line 📬📢"
2. Simple explanation
An everyday analogy: coffee buzzer, hotel key card, fuse box.
3. 3–5 bullets
Emoji bullets, one idea each. No jargon without a definition.
4. Visual
Screenshot a diagram from these pages, or make a carousel of 5–8 slides.
5. Takeaway + question
"Rule of thumb: … Which do you use? 👇"
6. 3–5 hashtags
#SystemDesign #Integration #APIs #GenAI #Architecture
- Keep it under ~1,300 characters. Use short lines and white space.
- One concept per post. Turn "X vs Y" topics into a series.
- Add a real lesson from your own work. It beats textbook content every time (leave out confidential details).