SLOP MADE
SYSTEM DESIGN
THE SKILL THAT MATTERS.

THE PROBLEM AI MADE

THE CODE IS CHEAP NOW.
THE JUDGMENT
IS NOT.

When a model can produce a service in an afternoon, the question is no longer whether you can write it. It is whether you should, how it fails at three in the morning, what it costs at ten times the load, and what you cut. That judgment is what interviews test, what senior engineers are paid for, and what a generator cannot do for you. The details change with every new framework. The way of thinking does not.

THE LOOP

PROBLEM.
PAPER.
GRADE.

1. 1

   Get a problem.

   Real scale, real constraints, real ambiguity. You are expected to ask what is missing.

2. 2

   Draw it.

   Paper, whiteboard, tablet. Photograph it.

3. 3

   Get graded.

   Scored against the question's rubric, one grade per dimension, with what the grader saw on your page quoted back to you.

4. 4

   Fix one thing.

   The coach picks the highest-leverage gap and hands you a drill for it.

5. 5

   Share the card.

   One image with your design, your score and your next drill. Compare with friends or a study group.

THE RITUAL

NUMBERS
BEFORE BOXES.

1. 05:00 FRAMING

   A strong paper says the problem back in one sentence before anything else.

2. 10:00 ESTIMATES

   Five numbers before the first box: volume, QPS with a peak multiplier, payload and egress, concurrency by Little's Law, and the judgment line.

3. 15:00 DESIGN

   Boxes only after the numbers, and the cache drawn rather than implied.

4. 05:00 PARKING LOT

   Every prompt item and every interviewer question goes in, and it closes out loud before time.

THE SKILL

THE ONE AREA OF ENGINEERING
WHERE THE HUMAN IS
THE POINT.

Every system design conversation is a negotiation between constraints, and the constraints are never all written down. Latency against cost. Consistency against availability. The team you have against the team you wish you had. Models are good at listing options. Choosing, and explaining the choice to another person, is the job. That is why the interviews are hard and why the role pays. We built a place to practice exactly that part.

FROM THE FOUNDER

I SAT IN
THOSE ROOMS.

I have shipped video systems at YouTube, Meta, Netflix, Tubi and Apple, and the skill that mattered in every one of those rooms was the same: draw the system, defend it, change your mind when the numbers say so. The rise of generated code did not make that skill less important. It made it the whole game. People online kept asking me to show proof that I use AI to help people get better at things, and my son's athletic performance was not enough for them. So here is us helping people get better at music, and get better at system design. The point of AI here is to teach you to make things yourself.

Steven Ojo, Affirmi

THEN SHOW YOUR WORK

ONE CARD.
YOUR SCORE.
YOUR PAPER.

Every debrief makes a card you can post.

BETA

LVLUP,
ONE DRILL
AT A TIME.

A problem bank across storage, messaging, caching, streaming, search and payments. Photo grading of hand-drawn designs. Drills ranked by your own gaps. A share card for every attempt. Progress you can point at.

Web practice works today. iOS and Android follow.