Untacit.

Untacit · Structured thinking for the age of AI

Make tacit knowledge visible.

In the age of AI, execution gets cheaper. Judgement becomes the advantage. Untacit uses System Design as a practice ground for structured thinking—turning experience, intuition, and judgement into reasoning you can see, test, explain, and improve.

Learn System DesignBrowse case library
  • Make judgement visible
  • Make methods practicable
  • Make experience transferable
Visible reasoningThinking in progress

Ambiguous problem

How do you turn an ambiguous requirement into a reviewable system design?

1Clarify · Remove false understanding
2Scope · Draw the system boundary
3Design · Split responsibilities and flows
4Evaluate · Weigh bottlenecks and costs
5Communicate · Explain why

Learn the method, then practise real problems

One stable path. One growing case library.

Build the complete System Design reasoning method first, then practise it across an expanding set of real cases. New cases never move the finish line for your core curriculum.

01Finite learning path

Learn the method

Learn System Design

Work through Clarify, Scope, Design, Evaluate, and Communicate to build a reusable way to reason about ambiguous requirements.

Enter learning path →
02Continuously updated

Practise with real cases

System Design Case Library

Practise the same reasoning method across AI systems, social feeds, transactions, and consistency problems. Every case can be started independently.

Explore cases →

The Untacit method

Turn experience and intuition into a method you can practise

Great engineers often know more than they can explain. Untacit makes that tacit judgement inspectable and practicable, with System Design as the practice ground.

  1. 01

    Think · See the judgement

    Move actors, outcomes, assumptions, boundaries, and trade-offs out of one person’s head and into a shared model.

  2. 02

    Make · Produce evidence

    Use sorting, comparison, simulation, and canvases to turn understanding into something testable.

  3. 03

    Explain · Transfer the method

    Explain why the decision holds, what would overturn it, and how someone else can reuse the reasoning.

Tacit → Untacit

Good judgement should not live in one person’s head

The course does not hand you conclusions. You expose your default assumptions first, then inspect the structure behind expert judgement.

Select a card to turn intuition into inspectable reasoning

Thinking exercise preview

Interactive

Free early access

The complete Untacit experience, free during early access

Explore every interactive lesson and case study while we learn what helps people practise System Design reasoning most effectively.

Create a free account →Browse the learning path

Early access is free for now. We may introduce paid plans later, but we will explain any change before it takes effect.

Current access

Free

Early Access

Everything is open

  • The complete interactive System Design course
  • Every current and newly published case study
  • Interactive exercises and simulations
  • Saved progress and your practice history

Why create an account?

Your account saves learning progress and helps us understand which parts of the experience need improvement.

  • 01At least one deep-dive System Design case every month
  • 02Ongoing improvements to exercises and existing cases

Use it in real work

The hard part happens before the boxes and arrows

Untacit focuses on the judgement that precedes an architecture diagram: what the problem is, where the boundary belongs, and which cost is worth paying.

01

Handle ambiguous requirements

See the user, outcome, scale, success criteria, and assumptions nobody said aloud.

02

Draw system boundaries

Decide what this design will solve, what it will not, and where responsibilities should separate.

03

Explain architecture trade-offs

State why this option wins, which costs it accepts, and what change would overturn the choice.

A growing practice ground

Turn the method into judgement with real cases

The core curriculum has a clear finish line; the case library keeps growing. Choose a system and complete your next design under concrete constraints.

Enter the case library