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SD-2N 99% BUILDER

SD-2N · Two Nines · 99%

Runbookly Certified System Design Builder

Proves you can keep systems running at the Two Nines level of the System design lab: you solved the level in the simulator, then built and repaired real systems in a timed practical exam, without being able to test them.

Practice
3 tasks · 70 %
Theory
15 questions · 30 %
Duration
1 h 30 min + 1 pause of 10 min
To pass
70 % overall, 60 % in practice
Results
24 hours later
Valid
24 months

The exam: practice first, then theory

70 %

Practice in the simulator

3 tasks in the lab you trained in: systems to build from a brief, or to repair. Some come from the level's exercises with other data, most were written for the exam only and are never published.

During the exam you cannot run the simulation: you build or repair, then submit. After the exam our servers replay each system through its day of traffic and failures, and grade it against its objectives.

30 %

Theory

Questions on production situations and on the concepts of the level, drawn for you among the level's exercises and the certification's own bank.

You pass with 70 % overall and at least 60 % in practice: a certified engineer must make systems hold, not only know the answers.

What to master

Every concept below can be asked, and every exercise of the level becomes a scenario of the exam.

The level's exercises

  1. URL shortener
  2. Pay only for office hours
  3. Checkout that never waits
  4. Too many connections
  5. Authentication is the bottleneck
  6. Search without melting the database
  7. A slow payment provider

Read the preparation guide →