Two serious preparation modes

Practice deliberately. Interview realistically.

Untimed

Practice Mode

Work without a countdown, save encrypted drafts, reveal progressive hints, run custom inputs, submit against visible and hidden tests, and unlock the post-solve editorial.

No streak penalty or pressure mechanics.
Visible examples and protected hidden tests.
Submission history, runtime, memory, and feedback.
Editorial unlock after solving.

Open Practice Mode

Server timed

Interview Mode

The clock is owned by Efibb, survives refreshes and reconnects, locks the interview language, and automatically submits saved work when time expires.

30, 45, 60, and 90-minute formats.
Balanced randomized challenge sets.
Strict or guided-hint blueprints.
Post-interview readiness report and editorials.

Interview blueprints

Choose the pressure level that matches your preparation.

30 minutes1 question

30-Minute Technical Screen

One focused interview question under a server-authoritative 30-minute clock.

Hints: Disabled

45 minutes1 question

45-Minute Coding Interview

A standard single-question interview with enough time for clarification, implementation, and testing.

Hints: Disabled

60 minutes2 questions

60-Minute Two-Question Interview

Two balanced questions with automatic final submission when the interview closes.

Hints: Disabled

90 minutes3 questions

90-Minute Interview Loop

A three-question interview set spanning implementation depth and engineering judgment.

Hints: Disabled

45 minutes2 questions

Guided Interview Practice

A timed practice interview where progressive hints remain available and are reported.

Hints: Available and reported

Execution boundary: the interview workflow can be evaluated with the runner disabled, but real compile/test scoring requires the separately certified sandbox. Efibb never falls back to executing learner code in the web process.