What Real-World Design Problems Can You Practice in a System Design Course?

Author : Abhinay Gadi | Published On : 28 Sep 2026

Introduction

System design becomes easier when learners practice realistic problems instead of memorizing terms. A good design problem forces them to decide what the system should do, how much traffic it may receive, where data belongs, and what trade-offs are acceptable.

A System Design Course can help learners practice problems that gradually increase in complexity. Beginners can start with small services such as a URL shortener or file-sharing application, then move toward chat systems, e-commerce platforms, social feeds, ride booking, video streaming, and notification platforms. The purpose is not to copy one perfect architecture. It is to develop a repeatable way to reason about requirements, scale, data, APIs, failures, and bottlenecks.

Problem 1: Design a URL Shortener

A URL shortener is a common beginner problem because the main workflow is easy to understand.

The system accepts a long URL and returns a short code.

Later, when a user opens the short link, the service redirects them to the original URL.

Learners can discuss:

How short codes are generated.

Where mappings are stored.

How redirects are cached.

How duplicate codes are avoided.

How popular links are handled.

Problem 2: Design a File-Sharing Service

A file-sharing system teaches learners to separate file metadata from the files themselves. The design can cover uploads, downloads, permissions, object storage, and shareable links. Learners can also discuss upload reliability and how a CDN may improve downloads for users in different locations.

Problem 3: Design a Chat Application

A chat application introduces real-time communication.

Requirements may include one-to-one messages, groups, delivery status, read status, presence, and history. Learners can ask how persistent connections work, how offline users are handled, where history is stored, whether strict ordering matters, and how notifications are sent.

This problem helps learners understand state, real-time connections, queues, and distributed messaging.

Problem 4: Design an E-Commerce Platform

E-commerce combines several business areas.

Possible components include:

Catalog.

Search.

Cart.

Inventory.

Orders.

Payments.

Notifications.

Learners can begin with one application and then identify which parts need independent scaling.

A useful discussion is what happens during checkout.

The system may need to reserve inventory, create an order, process payment, and send confirmation.

What happens if payment succeeds but the next step fails?

This introduces transactions, compensation, idempotency, and asynchronous processing.

Problem 5: Design a Notification System

A notification platform may deliver email, SMS, push, and in-app messages. A queue can buffer requests so the main user action does not wait for delivery. Separate workers can process channels while learners consider retries, provider failure, rate limits, and dead-letter queues.

Problem 6: Design a Social Media Feed

A social feed introduces a different kind of scale.

Users follow other users and expect recent posts to appear quickly.

Questions include:

How are posts stored?

How is a user feed generated?

Should feeds be calculated when someone opens the app or prepared earlier?

How are popular accounts handled?

What should be cached?

This introduces the trade-off between doing work during reads and doing work during writes.

Beginners do not need one universal answer. They should explain which strategy fits the expected usage pattern.

Problem 7: Design a Ride-Booking Application

Ride-booking systems introduce location and real-time matching.

The design may need to handle:

Drivers updating location.

Users requesting rides.

Nearby-driver search.

Ride matching.

Trip status.

Payments.

Notifications.

Location data changes frequently, so the storage and querying strategy differs from a normal user-profile database.

Learners can discuss geographic indexing, frequent updates, event-driven workflows, and what happens when a driver accepts a ride at the same time as another matching attempt.

Problem 8: Design a Video-Streaming Platform

A video-streaming problem helps learners separate application metadata from large media delivery.

The system may include accounts, catalog, search, recommendations, playback history, media storage, and CDN delivery. Large video files should generally be served through infrastructure designed for media rather than ordinary application servers.

This problem introduces CDNs, storage, geographic distribution, caching, and bandwidth considerations.

Problem 9: Design an Online Ticket-Booking System

Ticket booking introduces concurrency.

Two users may attempt to reserve the same seat at nearly the same time.

The system needs a way to avoid selling one seat twice.

Learners can discuss:

Temporary reservations.

Database transactions.

Locking.

Reservation expiry.

Payment failure.

High-traffic events.

This problem is useful because it shows that scalability is not only about serving more requests. Correctness under concurrent activity also matters.

How Should Learners Approach Every Problem?

Use a repeatable sequence.

First, clarify functional requirements.

Then identify non-functional requirements such as scale, availability, latency, and consistency.

Estimate rough traffic and storage.

Define APIs.

Choose a data model.

Draw the high-level components.

Find likely bottlenecks.

Discuss failures.

Explain trade-offs.

This structure is more valuable than memorizing one architecture diagram.

Why Should Designs Start Simple?

Beginners often add microservices, queues, caches, and several databases before identifying a need for them.

Start with the simplest architecture that satisfies the initial requirements.

Then introduce complexity when a clear bottleneck appears.

For example, add caching because repeated reads overload the database, not because every system-design diagram is expected to contain a cache.

This produces designs that are easier to explain and defend.

Frequently Asked Questions

Which system design problem should beginners practice first?

A URL shortener, notification service, or simple file-sharing system is a good starting point because the core requirements are easy to understand.

Should every design use microservices?

No. Start with the simplest suitable architecture. Microservices should be introduced only when independent scaling, deployment, ownership, or other requirements justify them.

Are exact traffic estimates required?

No. Approximate calculations are usually enough to guide architecture decisions and identify likely bottlenecks.

How can learners know whether their design is correct?

System design often has multiple valid answers. A strong design explains assumptions, meets requirements, handles key failures, and clearly describes its trade-offs.

Conclusion

Real-world practice is one of the most effective ways to learn system design.

A System Design Course can help learners work through URL shorteners, file sharing, chat, e-commerce, notifications, social feeds, ride booking, video streaming, and ticket booking.

Each problem introduces a different design challenge. Some emphasize scale, others consistency, real-time communication, large files, concurrency, or asynchronous work.

The goal is not to memorize ten finished diagrams. It is to develop a repeatable process: clarify requirements, estimate scale, design the simplest workable architecture, identify bottlenecks, handle failures, and explain trade-offs.

Once learners can apply that process to unfamiliar problems, they are building real system-design skill.