Decagon Coding Interview Questions

Build a sophisticated data structure that records time-stamped ratings and computes sliding-window statistics including percentiles, recently asked in interviews at Decagon. This problem assesses your ability to maintain time-ordered collections, handle dynamic updates efficiently, and execute range-based queries under strict performance constraints. It is an ideal challenge for testing advanced data structures and algorithmic efficiency. Access the complete problem specification and expert implementation details with a paid subscription.

Asked during Decagon interviews, this combinatorial puzzle asks you to compute every possible unique sequence of turns in a traditional grid game. Rather than just looking at final outcomes, you must track the chronological order of moves for both participants, accounting for early terminations triggered by winning alignments or full boards. It examines your depth-first search strategy and combinatorial counting skills. To view the complete problem statement and reference solution, a subscription is required.

Build a flexible e-commerce basket management system that handles item dependencies, cumulative quantity discounts, and historical state changes, as seen in Decagon technical screens. This problem evaluates your skill in maintaining relational states, aggregating inventory metrics, and implementing undo-redo functionality cleanly. You will practice structuring modular data classes to handle complex business rules without performance degradation. Unlock the full exercise guidelines and reference code by subscribing.

Tackle advanced data stream management with this algorithmic coding problem featured in Decagon interviews. The task challenges you to design a specialized component capable of tracking records within a moving temporal window and computing running averages dynamically. You will need to carefully balance insertion efficiency and time-bound aggregation to handle continuous data streams effectively. Unlock the full problem specifications and optimal software design implementation by subscribing today.

This Decagon interview scenario asks you to calculate missing ingredients and respective quantities by comparing a user selected set of recipes against their current pantry inventory. The exercise tests your ability to aggregate hierarchical data, manage inventory states, and perform precise dictionary lookups or arithmetic difference operations. It measures your backend logic formulation and data manipulation skills under real-world constraints. Unlock the full problem specifications and the optimal solution by purchasing a subscription.

This advanced coding challenge, reported from Decagon interview loops, requires you to design a robust shopping cart system that manages item quantities and complex discount rules while supporting nested database-style transactions. You will need to implement transactional boundaries, including savepoints, rollbacks, and commits, testing your ability to maintain internal state integrity under multi-layered modifications. It is a great test of object-oriented design and stack-based state management. To view the complete problem statement and implementation details, a subscription is required.

This Decagon interview question explores combinatorial game theory by asking you to enumerate all valid move sequences for a restricted board game variant. The challenge assesses your skills in recursive backtracking, state space search, and efficient termination tracking under custom winning conditions. You will need to handle deep branching factors while avoiding redundant state evaluations. Access the full problem details and algorithmic solution by purchasing a subscription.

Mastering time-bounded data streams is essential for backend engineering interviews, and this Decagon coding challenge evaluates your ability to efficiently manage chronological records. You will design a custom window tracker that continuously prunes outdated entries while maintaining accurate running calculations as new timestamps arrive. This exercise tests your proficiency with data structures and temporal constraints in a streaming context. Access the complete problem description and expert solution by upgrading to a paid subscription.