2nd/10_Wiki/Topic_Programming/Architecture/Problem Solving Skills.md

id, title, category, status, canonical_id, aliases, duplicate_of, source_trust_level, confidence_score, verification_status, tags, raw_sources, last_reinforced, github_commit, tech_stack

id	title	category	status	canonical_id	aliases	duplicate_of	source_trust_level	confidence_score	verification_status	tags	raw_sources	last_reinforced	github_commit	tech_stack
wiki-2026-0508-problem-solving-skills	Problem Solving Skills	10_Wiki/Topics	verified	self	Problem Solving 문제 해결 능력 debugging skills	none	A	0.9	applied	meta debugging engineering methodology		2026-05-10	pending	language framework meta methodology

Problem Solving Skills

매 한 줄

"매 problem 정의가 매 solution의 매 절반". Problem solving은 매 ill-defined situation을 매 well-defined sub-problems으로 매 decompose하고 매 hypothesis-test loop으로 매 narrow down하는 매 transferable skill set. Polya (1945) 4-step부터 매 modern debugging 까지 매 동일한 backbone.

매 핵심

매 Polya 4-step (1945)

1. Understand: 매 input/output/constraint 매 명시.
2. Plan: 매 known similar problem과 매 mapping.
3. Execute: 매 plan 매 step-by-step.
4. Review: 매 result verify, 매 generalize.

매 Debugging 전용 loop

• 매 Reproduce: 매 minimal repro case.
• 매 Bisect: 매 git bisect / binary search.
• 매 Hypothesize: 매 1개 변수만 매 변경.
• 매 Verify: 매 test 매 추가.
• 매 Postmortem: 매 root cause + prevention.

매 응용

1. Production incident response (5-why).
2. Algorithm design (decomposition + invariants).
3. LLM prompt debugging (delta isolation).

💻 패턴

Minimal repro extraction

# Bisect a failing input down to minimal case
def minimal_repro(input_list, fails):
    while True:
        for i in range(len(input_list)):
            candidate = input_list[:i] + input_list[i+1:]
            if fails(candidate):
                input_list = candidate
                break
        else:
            return input_list

Git bisect automation

git bisect start HEAD v1.0.0
git bisect run pytest tests/test_regression.py::test_bug
# 매 Bisect 자동 종료 → first-bad-commit 매 출력

5-why root cause

# postmortem.yaml
incident: api 500 spike
why_1: db connections exhausted
why_2: connection leak in /search handler
why_3: exception bypassed `with` cleanup
why_4: custom context manager swallowed asyncio.CancelledError
why_5: copy-pasted snippet from Stack Overflow without review
fix: replace with asynccontextmanager + add lint rule

Hypothesis-driven test

# Change ONE variable per iteration
import time
def measure(config):
    t = time.time(); run(config); return time.time() - t

base = {"batch": 32, "workers": 4, "cache": True}
for k in base:
    cfg = {**base, k: not base[k] if isinstance(base[k], bool) else base[k]*2}
    print(k, measure(cfg))

Rubber-duck logger

def trace_state(label, **vars):
    print(f"[{label}]", " | ".join(f"{k}={v!r}" for k, v in vars.items()))

trace_state("before-loop", i=0, total=len(data), seen=set())

매 결정 기준

상황	Approach
Bug 매 reproducible	Bisect + minimal repro
Bug 매 intermittent	Logging + statistical test
Algorithm 매 unknown	Polya + analogy from known
Production incident	5-why + postmortem

기본값: Reproduce → Bisect → Hypothesize → Verify → Document.

🔗 Graph

• 부모: Debugging
• 변형: Polya-Method · Bisect
• 응용: Postmortem
• Adjacent: Scientific Method

🤖 LLM 활용

언제: 매 ill-defined task decomposition, 매 stuck-state escape, 매 LLM prompt 디버깅. 언제 X: 매 trivial 1-line typo (overhead).

❌ 안티패턴

• 매 Shotgun debugging: 매 random 변경 후 매 동작하면 commit.
• 매 Symptom-only fix: 매 root cause 무시.
• 매 No repro: 매 "내 환경에선 됨".
• 매 Heisenbug 회피: 매 logging 추가하면 매 사라지는 bug 매 무시.

🧪 검증 / 중복

• Verified (Polya "How to Solve It" 1945, Zeller "Why Programs Fail" 2nd ed.).
• 신뢰도 A.

🕓 Changelog

날짜	변경
2026-05-08	Phase 1
2026-05-10	Manual cleanup — Polya + debugging loop + repro/bisect patterns