Format and types
Usually after the résumé screen, candidates solve several problems online in two to five hours, judged by hidden test cases. Expect implementation, brute force, BFS/DFS, greedy, binary search, dynamic programming and graphs; judging whether O(N²) is fast enough is key. Python, Java or C++ are usually allowed.
Preparation
Learn syntax, data structures, then problem types, then timed mock tests. If the coding test comes first in the hiring sequence, prioritize it and build a portfolio in parallel. Korea's K-Digital Training courses often include algorithms.
FAQ
- How many problems per day?
- Understanding types matters more than volume.
- Is searching allowed?
- It depends on the company's rules.
Sources reviewed: 2026-10-26
References
- Cormen, T. H., et al. (2022). Introduction to Algorithms (4th ed.). MIT Press.
- 고용노동부 K-디지털 트레이닝 안내. https://www.work24.go.kr
- Laakmann McDowell, G. (2015). Cracking the Coding Interview (6th ed.). CareerCup.