Coding Round
One or two problems in 45 minutes, usually in a shared editor. The interviewer watches how you get there: pinning down the input, naming an approach before you type, tracing an example, and stating the cost.
Start a Session
Set a level to tune the cards. Cards you rated Shaky come up more often.
How It's Graded at Each Level
- Junior
A working solution to an easy or medium problem, readable code, and an honest complexity answer.
- Mid
Mediums without hints, the better approach named before coding, and edge cases tested out loud.
- Senior
Quick pattern recognition, a clean optimal solution with time to spare, and follow-ups handled on the spot.
- Staff
The Senior bar on the code, plus the tradeoffs between approaches and how the code behaves in production.
- Principal
Rarely the deciding round. Clear reasoning, clean code, and the judgment to pick the simple answer when it's enough.
Drill Types
- SolvePlan the approach to a full problem, then check it against the solution.10 to 20 min a problem
- Pattern TriageRead a problem and name the pattern it reduces to.About 1 min a card
- Write the CodeType the solution in Java or Python and compare.10 to 15 min a problem
- Complexity AnalysisRead a snippet and give its time and space.About 1 min a card
- Big O QuizCosts of common operations and data structures.30 sec a card
- AlgorithmsPick the right classic algorithm for the scenario.About 1 min a card
Read These First
All Pattern Guides- PatternSliding WindowPattern
- PatternTwo PointersPattern
- PatternTop K ElementsPattern
- PatternMonotonic StackPattern
- PatternDynamic ProgrammingPattern
- GuideBig O ReferenceGuide
Common Mistakes
Coding before there's a plan
Say the approach and its cost first. A rewrite at minute 30 costs more than five minutes of planning.
Skipping the small example
Trace one input by hand before and after you code. It catches most off-by-one bugs.
Working in silence
The interviewer grades your reasoning as much as the result. Say what you're choosing and why.
Guessing the complexity
Count the loops and the cost of each data structure operation, then give time and space together.
Matching Mock
Mixed Timed Drill
A timed set of Pattern Triage, Complexity, System Design, Tradeoffs, and Behavioral cards, with a report at the end.