Level 0 · Orientation
An app, a server and a database
First, the basics: your phone asks a server for something and the server looks it up in a database. You learn what happens at every hop, even if you have never written code.
System design, one 12-minute class at a time.
An online course on how software that serves millions of people is built, and how to explain it in an interview. You take twelve-minute classes, draw cases that get checked for you and practise mock interviews with AI. You can start from scratch.
No card. Levels 0 and 1 (37 classes) are free and never expire.
Level 1 · Foundations
More users arrive: more servers and a load balancer
When one server is not enough, you run several behind a load balancer that spreads the traffic. You learn APIs, DNS, load balancing and how to estimate the load before it arrives.
Level 2 · Data
Data that is fast and safe
A cache so you don't ask the database for everything, and a replica in case it goes down. Data models, indexes, replicas, partitions and transactions.
Level 3 · Distributed systems
What can wait goes into a queue
Sending an email or processing a video does not have to happen this second: it goes to a queue and a worker does it. Retries, idempotency, events and what to do when two machines disagree.
Level 4 · Reliability, security and cloud
Don't go down, and if you do, recover
Monitoring, backups, SLOs, security and cost: what a demo is missing before it can hold up in production. Many courses skip it.
Level 5 · AI systems
And now, AI
Vectors, RAG, language models, agents and what each answer costs. You learn to design an AI product that keeps working when thousands of people use it.
Level 6 · Cases and mocks
You design it, and you defend it
You draw 23 real cases on a canvas that checks your diagram and practise with an AI interviewer that scores you with a rubric, so the real interview is not the first time you do this.
Level 0 · An app, a server and a database
What it is, in 30 seconds
A course to learn how to design software systems by practising, with your work reviewed automatically. It runs in the browser; nothing to install.
- Learn
206 twelve-minute classes
Across 41 modules and 7 levels. Each class is one idea with an everyday example, the technical version, a quiz and cards so you don't forget it.
- Practise
23 cases you draw
You build the architecture of a real system on a canvas. Rules tell you at once what breaks, and the AI reviews your design citing your own components.
- Prove it
Mock interviews with AI
Timed, with a twist halfway through. The score goes dimension by dimension and quotes what you said, so you know how you're doing before the real interview.
For someone like you
Illustrative profiles: invented people who show who the course is for. They are not testimonials.
- Illustrative
Dani
Mid backend engineer, 4 years
Guadalajara
Has an interview with a US company in six weeks, and the system design round is the one that worries them most.
Their route: System design interviews
- Illustrative
Mariana
Product manager
Mexico City
Doesn't code. Wants to understand why the team asks for two sprints to “just add a cache” and push back with arguments.
Their route: From scratch
- Illustrative
Luis
AI consultant
Monterrey
Deploys agents with customers and needs to explain cost, security and legacy integration without improvising.
Their route: Forward Deployed Engineer
- Illustrative
Sofía
Engineering student
Bogotá
Knows basic programming and wants to reach her first interviews understanding how a whole system fits together.
Their route: From scratch, then Senior
- Illustrative
Andrés
Tech lead
Lima
His company is moving to AWS and he wants the Solutions Architect certification with the design side understood, not memorised.
Their route: AWS Solutions Architect
Choose where you're headed
When you sign up you answer six questions and the course orders itself for you: which modules, in what order and in how many weeks at your pace. Not sure of your level? A 15-minute diagnostic places you.
From scratch
13 modulesCovers levels 0, 1, 2, 3, 5
System design interviews
20 modulesCovers levels 0, 1, 2, 3, 4, 5, 6
Grow to senior or architect
27 modulesCovers levels 0, 1, 2, 3, 4, 6
Solutions Architect
23 modulesCovers levels 0, 1, 2, 3, 4, 5, 6
Forward Deployed Engineer
21 modulesCovers levels 0, 1, 2, 3, 4, 5, 6
AI systems
18 modulesCovers levels 0, 1, 2, 3, 4, 5, 6
AWS Solutions Architect (SAA-C03)
18 modulesCovers levels 0, 1, 2, 3, 4
AWS generative AI (AIP-C01)
13 modulesCovers levels 0, 1, 2, 5
The whole course
41 modulesCovers levels 0, 1, 2, 3, 4, 5, 6
What's inside
What you use to learn and practise, plus the review that makes it stick.
206 short classes in 41 modules
10 to 15 minutes each: the simple idea first, then the precise version, then how it looks in a real system. Every class ends with a quiz.
23 cases with a canvas and automatic review
You draw the architecture. Rules flag single points of failure and bottlenecks, and the AI reviews your design citing your own components.
AI mock interviews with a rubric
A timed session with a twist halfway through. At the end you get a score per dimension that quotes what you said.
Spaced review
Cards come back just before you would forget them (the FSRS algorithm). Five minutes a day is enough.
From the diagram to AWS, GCP and Azure
67 components mapped to the services of all three clouds, so you know what each one calls the box you drew.
AWS certifications
The course marks which modules cover the objectives of two exams: AWS Certified Solutions Architect – Associate (SAA-C03) and AWS Certified Generative AI Developer – Professional (AIP-C01). Every cloud component carries the exam domain it belongs to.
Your progress page shows how far you are from each one: a module counts once you can solve it unaided.
It prepares the design side: choosing the architecture and defending the trade-off. For the exam itself, add AWS's official practice exams.
Not affiliated with or endorsed by AWS. AWS and its certification names are trademarks of Amazon.com, Inc. or its affiliates.
Certification readiness
AWS SAA-C036/17 modules ready
AWS AIP-C012/8 modules ready
Start free. Go Pro when you want everything.
Free
$0forever
All of levels 0 and 1: 37 classes, 2 design cases and 1 mock interview a month. No card, no expiry date.
Create a free accountPro
$9a month
Or $69 a year (≈ $5.75 per month). All 206 classes, all 23 cases, 8 mock interviews a month and the SAA-C03 and AIP-C01 readiness view.
See plansQuestions
Do I need prior experience?
No. If you don't code, you start with a welcome module that explains what a server, a database and an API are with everyday examples, and the first-day survey builds a route that steps up gradually. If you already code, you skip the basics.
What language is it in?
English and Spanish, all of it: the 206 classes, the cases, the interviews and the interface, one click apart. Recommended videos and readings are free third-party resources; where a good one exists in Spanish the Spanish version uses it.
What does the free plan include?
Levels 0 and 1 (37 classes), 2 design cases, spaced review and 1 mock interview a month. It does not expire.
Does it help with AWS certifications?
With the design side, yes: modules are marked with SAA-C03 and AIP-C01 objectives and your progress shows how far you are. It is not official AWS material and does not replace their practice exams.
Can I cancel any time?
Yes, from your account. You keep Pro until the end of the period you paid for, and your progress is never deleted.
How do I pay?
By card, through Stripe. If you have a discount code, enter it at checkout.
What does the AI do with what I write?
Your answers and diagrams are sent to the AI provider only to grade them or reply to you. The details are in the privacy notice.