Should We Implement a Code Review System?

Yes, absolutely.

This applies regardless of company size; even with just two programmers, it should be implemented. Many people think Code Review wastes time or is just about finding faults, but that's not the case at all. Let me give you a simple analogy:

You've written a very important report, ready to send to the big boss. Before hitting "send," wouldn't you ask a trusted colleague to read it over for you? To check for typos, awkward phrasing, or incorrect data?

Code review does exactly this. It's just that the "report" is replaced by "code," and the "boss" is replaced by "users."

Doing this has several immediate benefits:

1. Early problem detection, lowest cost. If a bug is discovered by a colleague right after the code is written, it might take only a few minutes to fix. But if this bug goes unnoticed, goes live with the product, and is encountered by users, the cost becomes huge. At best, users complain; at worst, the company loses money. By the time you go back to fix it, you'll need to re-familiarize yourself with the logic, test, and deploy, and a whole process could take half a day or a full day. Which cost is higher is obvious. Even the most experienced experts can make mistakes; having an extra pair of eyes is always a good idea.

2. Knowledge sharing, preventing "irreplaceability." What do startups fear most? That only one person understands a certain module, and if that person goes on vacation or leaves, that part of the business grinds to a halt, and no one dares to touch it. Code review can greatly alleviate this problem. When A writes code and B reviews it, even if B doesn't work on that specific business area, after seeing it enough, they'll understand the general logic. The same applies in reverse. Everyone reviewing each other's code gradually brings the entire team's technical level and understanding of the project up to par, preventing "knowledge silos."

3. Unified code style, easy maintenance. Imagine a project where some people like to write code one way, others another, resulting in a messy code style. Six months later, you might stare blankly at your own code for a long time. Not to mention maintaining someone else's "unreadable" code. Code review can enforce a unified standard, making the code look like it was written by a single person. Such code is easy for anyone to take over, and its readability and maintainability will be much higher.

4. Promotes communication and growth. The review process is actually a process of technical exchange. You can see how others solve problems, and others can offer you suggestions for improvement. For newcomers, this is one of the fastest ways to grow; for experienced members, it helps avoid working in isolation.

As for many people's concern about "slowing down development":

In the short term, it indeed adds a step. But in the long run, it saves you a lot of time fixing bugs, handling online incidents, and handing over projects. It's like driving; you can't remove the brakes and rearview mirrors just to go faster. Code review is your project's "brakes" and "rearview mirrors," allowing you to drive more steadily and further.

When first implementing it, people might be unaccustomed to it and feel like it's "fault-finding." Therefore, it's important to establish clear rules and a proper mindset: focus on the task, not the person; the goal is to make the product better, not to prove who is superior. Everyone is working for the good of the project; with the right mindset, this becomes much easier.