Code Room
Code reviewMedium
Question
Review this Java in-memory cache with lazy compute.
What a strong answer looks like
Separate real bugs from style. Rank issues by severity, point at the root cause rather than the symptom, and suggest a concrete fix — specific and kind.
Learn the concepts
public class ResultCache { private final Map<String, BigInteger> cache = new ConcurrentHashMap<>(); public BigInteger get(String key) { if (!cache.containsKey(key)) { BigInteger v = expensiveCompute(key); // seconds long cache.put(key, v); } return cache.get(key); }}Run or narrate your approach, then ask the coach.