Nodivex from TraitSpan

System design katas

A kata is a focused practice scenario. You get a brief with real constraints, sketch an architecture, run a simulation, and see what holds. Each kata trains a different aspect of system design thinking.

K

Coffee please

Retail Technology

Prevent double-charges under retries
Keep checkout responsive during peak rush
Beginner–Intermediate ~30 min
No signup requiredStart in under 2 minutesFeedback from simulation data
What is a system design kata

A repeatable exercise that turns system design into a testable skill

In martial arts, a kata is a sequence you practise until it becomes second nature. A system design kata works the same way: you receive a scenario with requirements and constraints, design a system to meet them, and get immediate feedback on what works and what breaks. Each repetition sharpens your judgment on trade-offs between latency, cost, reliability, and operability.

Kata library

Pick a kata and start practising

Each kata is a self-contained scenario. Open one, sketch a system, and see how it handles the constraints.

Beginner–IntermediateEducation Technology

Big news on campus

Serve a sudden surge of reads when thousands of users open the same notification at once.

IntermediateHealthcare

The waiting room

Give patients a fast booking acknowledgement while processing confirmations asynchronously.

Intermediate–AdvancedE-commerce

Checkout with change feeds

Separate transactional order writes from analytical reads using change feeds and read replicas.

IntermediateE-commerce

The flash sale

Keep checkout stable during a scheduled surge using admission control and queue buffering.

AdvancedLogistics

The multi-writer

Manage four competing actors writing to a shared database without contention degrading any single channel.

IntermediateFinancial Services

Legacy lifeline

Protect a fixed-capacity legacy system from modern traffic volumes without replacing it.

BeginnerFood Delivery

The meal deal

Size a food-ordering backend to survive the lunch rush without blowing the budget.

Beginner–IntermediateSports Media

Match day scores

Serve live sports scores to a massive audience using layered caching without overwhelming the origin.

Beginner–IntermediateRetail Technology

Coffee please

Prevent double-charges and duplicate orders during peak demand and retries.

IntermediateRetail

Three screens, one backend

Serve web, mobile, and in-store kiosk from shared infrastructure without one channel degrading another.

AdvancedFintech

Payment handshake

Process payments through an external gateway with tight error tolerance and async settlement.

Intermediate–AdvancedSaaS / DevOps

The status dashboard

Serve millions of status page reads during an incident using layered caching and read path isolation.

IntermediateSocial / Content Platform

The event feed

Publish events once and fan out to multiple subscribers without the slowest one dragging down the publisher.

IntermediateConsumer Internet

Ticket Drop

Keep checkout stable during an on-sale surge when a dependency partially fails.

Nodivex

Pick a kata and see what your design can handle

Open a scenario, sketch a system, and let the simulation show you the trade-offs.