您如何做出和记录重要的技术决策？

Question

您如何做出和记录重要的技术决策？

Accepted Answer

重要的技术决策应该是**深思熟虑、透明且有记录的**，而不是在某人的脑子里做出然后被遗忘。一个良好的流程可以展示权衡，建立共识，并留下痕迹，以便未来的工程师理解*为什么*，而不仅仅是*什么*。

## 决策框架

```text
1. FRAME the problem and the constraints (cost, time, team skill, scale)
2. LIST the realistic options — usually 2-4, including "do nothing"
3. EVALUATE each against the constraints and trade-offs
4. DECIDE, and state the reasoning explicitly
5. RECORD it (ADR) and communicate it
6. REVISIT if assumptions change
```

## 用ADR记录它

**Architecture Decision Record** 是一个简短、持久的笔记：

```markdown
# ADR 014: Use PostgreSQL for the new service

## Status: Accepted

## Context
We need a primary datastore. Team knows SQL; data is relational; scale is moderate.

## Decision
Use PostgreSQL.

## Consequences
+ Strong consistency, team familiarity, rich querying.
- Vertical scaling limits later; revisit if write volume 10x's.

## Alternatives considered
DynamoDB (rejected: relational data, team unfamiliar).
```

## 需要管理的权衡

记录所有内容会增加开销；不记录任何内容会导致机构知识流失。只为那些**成本高昂的决策**或未来工程师会质疑的决策保留ADR。

## 为什么这很重要

未记录的决策会被无休止地重新讨论，每位新工程师都会重新问