A
AiTechWorlds
AiTechWorlds
A structured path through distributed systems, database design, microservices, and the trade-offs that senior engineers and architects must master — including system design interview preparation.
System design is the art of making the right trade-offs under real-world constraints. Whether you are preparing for senior engineering interviews at FAANG companies or designing the architecture of a new product, this roadmap gives you the mental models and practical patterns you need.
Every distributed system can guarantee at most two of three properties:
| Property | Description | Example Systems |
|---|---|---|
| Consistency | Every read receives the most recent write | PostgreSQL, HBase |
| Availability | Every request receives a response (no errors) | Cassandra, DynamoDB |
| Partition Tolerance | System works despite network partitions | All distributed systems must have this |
In practice: CP systems favour correctness over availability (banking). AP systems favour uptime over perfect consistency (social media feeds).
| Pattern | Use Case | Trade-off |
|---|---|---|
| Monolith | Small teams, early-stage startups | Simple to deploy, hard to scale independently |
| Microservices | Large teams, complex domains | Scalable, but adds operational complexity |
| Event-Driven | Async workflows, notifications | Decoupled, but harder to debug and trace |
| CQRS | Read-heavy or write-heavy workloads | Optimised queries, but dual model complexity |
| Saga Pattern | Distributed transactions | Handles failures gracefully, complex to implement |
| Strangler Fig | Legacy system migration | Low risk migration, long timeline |
A well-designed system handles:
System design is not about memorising architectures — it is about developing the instinct to ask the right questions, identify the right bottlenecks, and choose the right tool for the specific job.
Yes — system design is an advanced topic that builds on solid programming and CS fundamentals. You should be comfortable with at least one backend language, understand databases, and have some experience building web applications before diving deep into system design.
System design focuses on the high-level structure of large-scale distributed systems — how services communicate, where data lives, and how the system scales. Software architecture is broader and also covers code-level patterns (MVC, clean architecture, DDD). Both are essential for senior engineers.
Extremely important for mid-level to senior roles. At companies like Google, Meta, and Amazon, system design interviews typically carry equal or greater weight than coding interviews for senior positions. You will be asked to design real systems in 45-60 minutes, including scalability, database choices, and trade-off justification.
Follow these steps in order. Required steps are marked — optional steps accelerate your learning.
Understand CAP theorem, consistency models, replication, and the fundamental challenges of building systems across multiple machines.
Learn horizontal vs. vertical scaling, reverse proxies (Nginx/HAProxy), caching strategies (LRU, write-through, write-back), and Redis/Memcached.
Master indexing, query optimisation, vertical/horizontal partitioning, consistent hashing, and when to choose SQL vs. NoSQL.
Service decomposition, inter-service communication (REST vs gRPC vs messaging), service discovery, API gateways, and the strangler fig migration pattern.
RESTful best practices, versioning, authentication (JWT/OAuth2), rate limiting, pagination, and when to consider GraphQL.
Understand async communication, Kafka, RabbitMQ, event sourcing, CQRS, and the Saga pattern for distributed transactions.
Content delivery networks, edge caching, object storage (S3-compatible), and designing systems for global low-latency delivery.
The three pillars: logs, metrics, and traces. Learn structured logging, distributed tracing (Jaeger/Zipkin), and dashboards (Grafana/Datadog).
TLS/mTLS between services, secrets management, zero-trust networking, OWASP top 10, and DDoS mitigation strategies.
Practice designing real systems (URL shortener, Twitter feed, ride-sharing, distributed cache) with full diagrams and trade-off discussions.
Ready to start your journey?
Begin with the first step. Consistency beats intensity — just 30 minutes a day.