W/Workbench
week 1 · day 1 · one composed session

Do today's work.
Not the whole roadmap.

01 / 60
your three-lane plan

One day. Three connected assignments.

Do these top-to-bottom. Do not pick a separate day from every roadmap: this Workbench day advances all three at deliberately different depths.

~2–3hone composed day
01Primary
Distributed systems · Boundaries, requirements & estimates

Model before code

Build the concept map: In your own words, define: functional vs non-functional requirements, back-of-envelope estimates, latency budgets, system boundaries, API contracts. Add one real example and one failure example for each. Do the modeling exercise: Estimate writes/day, redirects/second, and five years of storage for a shortener with 10M new links each month. Write every assumption. Write the pre-code brief: Write one page: problem, user, guarantees, non-goals, constraints, core data, and the first slice of URL shortener · baseline. Socratic design check: Answer the AI one question at a time. Change your brief only when the challenge reveals a real gap.

finish with

You can explain every term without copying a definition. Your assumptions and calculations are visible beside the answer. Another engineer could say what you will and will not build. You have recorded at least three clarified decisions.

if this becomes confusing
  • Draw the request or event timeline before naming infrastructure.
  • State the source of truth and the invariant before changing code.
  • When discussing scale, attach a number and a failure mode.
02Secondary
DSA · Complexity, arrays & hash maps

Build the structure

Maintenance version: spend 25–30 minutes on the smallest complete part of this assignment. Implement a dynamic array and a hash map with separate chaining. State each operation's expected and worst-case complexity.

finish with

One blank-file attempt plus a three-sentence explanation of the invariant.

if this becomes confusing
  • Write the brute-force approach before optimising.
  • State what remains true after each loop or mutation.
  • Use AI only after recording the exact step you cannot justify.
03Apply
Guided weekly labs · Guided lab · Model before code

URL shortener · baseline

Do the modeling exercise: Estimate writes/day, redirects/second, and five years of storage for a shortener with 10M new links each month. Write every assumption. Use the detailed lab below when you need the smaller steps.

finish with

Your assumptions and calculations are visible beside the answer.

if this becomes confusing
  • Wrong estimates are useful; hidden assumptions are not.
  • Use ranges when reality is uncertain.
important

Your primary roadmap gets the hardest thinking. Your secondary stays deliberately small. The vehicle is where knowledge becomes code, evidence, and judgment. Keep the same configuration for at least four weeks.

Detailed systems lab

Distributed systems is primary, so all cards marked today’s route are required.

URL shortener · baseline

Model before code

A bounded problem, written assumptions, and a design you can attack.

0/4
complete the reps in order
the ruleAttempt → expose the gap → use targeted help → prove it → explain from memory.
today's routelearn25 min

Build the concept map

In your own words, define: functional vs non-functional requirements, back-of-envelope estimates, latency budgets, system boundaries, API contracts. Add one real example and one failure example for each.

done when

You can explain every term without copying a definition.

where this gets confusing
  • Start from a concrete request timeline.
  • If a definition contains another vague term, unpack it too.
today's routebuild40 min

Do the modeling exercise

Estimate writes/day, redirects/second, and five years of storage for a shortener with 10M new links each month. Write every assumption.

done when

Your assumptions and calculations are visible beside the answer.

where this gets confusing
  • Wrong estimates are useful; hidden assumptions are not.
  • Use ranges when reality is uncertain.
today's routeexplain20 min

Write the pre-code brief

Write one page: problem, user, guarantees, non-goals, constraints, core data, and the first slice of URL shortener · baseline.

done when

Another engineer could say what you will and will not build.

where this gets confusing
  • Ban the words scalable and robust unless followed by a measurable meaning.
today's routereview15 min

Socratic design check

Answer the AI one question at a time. Change your brief only when the challenge reveals a real gap.

done when

You have recorded at least three clarified decisions.

where this gets confusing
  • Do not paste a blank page and ask AI to design it.
AI mode · Socratic tutor

Act as a Socratic systems tutor. I am building URL shortener · baseline. Do not give me an architecture. Ask one question at a time until my requirements, invariants, and failure assumptions are explicit. Challenge vague words like scalable, reliable, and fast.

when you are stuck

Use the debugging ladder.

  1. 01State expected vs actual behavior.
  2. 02Reduce to the smallest reproduction.
  3. 03List observations, not interpretations.
  4. 04Write three competing hypotheses.
  5. 05Run the cheapest distinguishing experiment.
  6. 06Only then ask AI for the next experiment.
field notes · saved locally

What did you learn by doing?