Summary – In doing a code review, you should make sure that:
The code is well-designed. The functionality is good for the users of the code. Any UI changes are sensible and look good. Any parallel programming is done safely. The code isn’t more complex than it needs to be. The developer isn’t implementing things they might need in the future but don’t know they need now. Code has appropriate unit tests. Tests are well-designed. The developer used clear names for everything. Comments are clear and useful, and mostly explain why instead of what, Code is appropriately documented (generally in g3doc). The code conforms to our style guides.
Make sure to review every line of code you’ve been asked to review, look at the context, make sure you’re improving code health, and compliment developers on good things that they do. Next: Navigating a CL in Review
What should a good code review look and feel like?
How to Make Good Code Reviews Better Essays, opinions, and advice on the act of computer programming from Stack Overflow. September 30, 2019 I have been doing day-to-day code reviews for over a decade now. The benefits of code reviews are plenty: someone spot checks your work for errors, they get to learn from your solution, and the collaboration helps to improve the organization’s overall approach to tooling and automation.
If you’re not currently doing code reviews in I have been doing day-to-day code reviews for over a decade now. The benefits of code reviews are plenty: someone spot checks your work for errors, they get to learn from your solution, and the collaboration helps to improve the organization’s overall approach to tooling and automation.
If you’re not currently doing code reviews in your organization, start now. It’ll make everyone a better engineer. Plenty of people and organizations have shared their code review best practices and what the definition of good code reviews mean to them.
Guides, and are all excellent reads. Below is my personal take on what good code reviews look like and how to make them even better at the team and organizational level. This is in the context of the tech environment I have been working at – currently at Uber, and before that at Skype/Microsoft and Skyscanner.
Good code reviews are the bar that all of us should strive for. They cover common and easy to follow best practices that any team can get started with, while ensuring high-quality and helpful reviews for the long term. Better code reviews are where engineers keep improving how they do code reviews.
These code reviews look at the code change in the context of the codebase, of who is requesting it and in what situation. These reviews adjust their approach based on the context and situation. The goal not only being a high-quality review, but also to help the developers and teams requesting the review to be more productive.
Good code reviews look at the change itself and how it fits into the codebase. They will look through the and. They cover the correctness of the code, test coverage, functionality changes, and confirm that they follow the coding guides and best practices.
- They will point out obvious improvements, such as hard to understand code, unclear names, commented out code, untested code, or unhandled edge cases.
- They will also note when too many changes are crammed into one review, and suggest keeping code changes single-purposed or breaking the change into more focused parts.
Better code reviews look at the change in the context of the larger system, as well as check that changes are easy to maintain. They might ask questions about the necessity of the change or how it impacts other parts of the system. They look at abstractions introduced and how these fit into the existing software architecture.
- They note maintainability observations, such as complex logic that could be simplified, improving test structure, removing duplications, and other possible improvements.
- Engineer describes great code reviews as a.
- The tone of code reviews can greatly influence morale within teams.
- Reviews with a harsh tone contribute to a feeling of a hostile environment with their microaggressions.
Opinionated language can turn people defensive, sparking heated discussions. At the same time, a professional and positive tone can contribute to a more inclusive environment. People in these environments are open to constructive feedback and code reviews can instead trigger healthy and lively discussions.
- Good code reviews ask open-ended questions instead of making strong or opinionated statements.
- They offer alternatives and possible workarounds that might work better for the situation without insisting those solutions are the best or only way to proceed.
- These reviews assume the reviewer might be missing something and ask for clarification instead of correction.
Better code reviews are also empathetic. They know that the person writing the code spent a lot of time and effort on this change. These code reviews are kind and unassuming. They applaud nice solutions and are all-round positive. Once a reviewer completes their review, they can either mark it approved, block the review with change requests, or not set a specific status, leaving it in a “not yet approved” state.
- How reviewers use the approve and request changes statuses is telling of the code reviews.
- Good code reviews don’t approve changes while there are open-ended questions.
- However, they make it clear which questions or comments are non-blocking or unimportant, marking them distinctively.
- They are explicit when approving a change – e.g.
adding a thumbs up comment like “looks good!”. Some places use acronyms like—these also work, but be aware that newcomers could misinterpret these insider acronyms for something else. Good code reviews are equally explicit when they are requesting a follow-up, using the code review tool or team convention to communicate this.
Better code reviews are firm on the principle but flexible on the practice: sometimes, certain comments are addressed by the author with a separate, follow-up code change. For changes that are more urgent than others, reviewers try to make themselves available for quicker reviews. Code reviews are usually done asynchronously and in writing through a code review tool.
This is usually out of convenience, to enable remote code reviews, and to allow multiple people to review the same code change. But when is it time to stop using the tool—however good it might be—and start talking face to face about the code? Good code reviews leave as many comments and questions as are needed.
If the revision does not address all of them, they will note those as well. When the conversation gets into a long back-and-forth, reviewers will try to switch to talking to the author in-person instead of burning more time using the code review tool. Better code reviews will proactively reach out to the person making the change after they do a first pass on the code and have lots of comments and questions.
These people have learned that they save a lot of time, misunderstandings, and hard feelings this way. The fact that there are many comments on the code indicates that there is likely some misunderstanding on either side. These kinds of misunderstandings are easier identified and resolved by talking things through.
- Nitpicks are are unimportant comments, where the code could be merged without even addressing these.
- These could be things like variable declarations being in alphabetical order, unit tests following a certain structure, or brackets being on the same line.
- Good code reviews make it clear when changes are unimportant nitpicks.
They usually mark comments like these distinctively, adding the “nit:” prefix to them. Too many of these can become frustrating and take the attention away from the more important parts of the review, so reviewers aim to not go overboard with these. Better code reviews realize that too many nitpicks are a sign of lack of tooling or a lack of standards.
- Reviewers who come across these frequently will look at solving this problem outside the code review process.
- For example, many of the common nitpick comments can be solved via automated linting.
- Those that cannot can usually be resolved by the team agreeing to certain standards and following them—perhaps even automating them, eventually.
Starting at a new company is overwhelming for most people. The codebase is new, the style of programming is different than before, and people review your code very differently. So should code reviews be gentler for new starters, to get them used to the new environment, or should they keep the bar just as high, as it is for everyone else? Good code reviews use the same quality bar and approach for everyone, regardless of their job title, level or when they joined the company.
Following the above, code reviews have a kind tone, request changes where needed, and will reach out to talk to reviewers when they have many comments. Better code reviews pay additional attention to making the first few reviews for new joiners a great experience. Reviewers are empathetic to the fact that the recent joiner might not be aware of all the coding guidelines and might be unfamiliar with parts of the code.
These reviews put additional effort into explaining alternative approaches and pointing to guides. They are also very positive in tone, celebrating the first few changes to the codebase that the author is suggesting. Code reviews get more difficult when reviewers are not in the same location.
They are especially challenging when reviewers are sitting in very different time zones. I have had my fair share of these reviews over the years, modifying code owned by teams in the US and Asia, while being based in Europe. Good code reviews account for the time zone difference when they can. Reviewers aim to review the code in the overlapping working hours between offices.
For reviews with many comments, reviewers will offer to chat directly or do a video call to talk through changes. Better code reviews notice when code reviews repeatedly run into timezone issues and look for a systemic solution, outside the code review framework.
- Let’s say a team from Europe is frequently changing a service that triggers code reviews from the US-based owner of this service.
- The system-level question is why these changes are happening so frequently.
- Are the changes done in the right codebase or should another system be changed? Will the frequency of changes be the same or go down over time? Assuming the changes are done in the right codebase and the frequency will not go down, can the cross-office dependency be broken in some way? Solutions to these kinds of problems are often not simple and could involve refactoring, creating of new services/interfaces or tooling improvements.
But solving dependencies like this will make the life of both teams easier and their progress more efficient for the long term, meaning the return on investment is often quite impressive. The way companies and their engineering organizations approach code reviews is a big element of how efficient they can be.
Organizations that view them as unimportant and trivial end up investing little in making reviews easier. In cultures like this, it might be tempting to just do away with code reviews entirely. Engineers advocating for doing better code reviews might feel isolated, without support from above and eventually give up.
The result is an organization where problems continue to repeat and compound upon themselves. Organizations with good code reviews ensure that all engineers take part in the code review process—even those that might be working on solo projects. They encourage raising the quality bar, and teams facilitate healthy discussions on code review approaches both at the team and org level.
These companies often have code review guides for larger codebases that engineers initiated and wrote. Organizations like this recognise that code reviews take up a good chunk of engineers’ time. Many of these companies will add code reviews as expectations to the developer job competencies, expecting senior engineers to spend a larger chunk of their time reviewing the code of others.
Organizations with better code reviews have hard rules around no code making it to production without a code review—just as business logic changes don’t make it to production without automated tests. These organizations have learned that the cost of cutting corners is not worth it; instead, they have processes for expedited reviews for urgent cases.
These organizations invest in developer productivity, including working continually to develop more efficient code reviews and tooling improvements. Helpful engineering executives don’t need convincing on the benefits of code reviews and other engineering best practices. Instead, they support initiatives on better tooling or more efficient code review processes that come from teams.
When people come across reviews that feel hostile, they feel they can speak up and have support all-round to resolve the issue. Senior engineers and managers consider code reviews that are not up to the bar just as much of an issue as sloppy code or poor behavior.
Both engineers and engineering managers feel empowered to improve how code reviews are done. Good code reviews already have lots of good effort going into them. They do a thorough review of the change itself, avoid being opinionated with the tone of comments, and make nitpicks clear. They maintain a consistent bar, regardless of who is requesting the review and try to make cross-time zone reviews less painful by paying additional attention to these.
Organizations that have good reviews ensure that every developer regularly receives and does code reviews. This is already a high bar—but if you get here, don’t stop. Code reviews are one of the best ways to improve your skills, mentor others, and learn how to be a more efficient communicator.
- Get to better code reviews by continuously improving on the details, but also start looking at changes at a high level as well.
- Be empathetic in the tone of comments and think of ways outside the code review process to eliminate frequent nitpicks.
- Make code reviews especially welcoming for new starters and look for systemic solutions for painful cross-time zone reviews.
Organizations that are forward-looking encourage investing in tooling and process improvements to make code reviews better, reaping more of the benefits. ——- Gergely is currently an engineering lead in Amsterdam. This blog post originally appeared on Gergely’s blog,,
If you’d like to read more from Gergely, you can subscribe to for his articles on engineering, tech leadership and distributed systems. If you would like to contribute articles to the Stack Overflow blog, send an email to [email protected]. Tags:,,, is a weekly conversation about working in software development, learning to code, and the art and culture of computer programming.
February 27, 2023 Everyone who says “tech debt” assumes they know what we’re all talking about, but their individual pictures differ quite a bit. : How to Make Good Code Reviews Better
What is important in code review?
The Benefits of Code Reviews – Code reviews provide several key benefits, including:
- Improves code quality–Code reviews improve code quality by detecting issues before they snowball out of control and ensuring consistent standards. This leads to robust software that is built from components for seamless integration and functionality.
- Supports knowledge transfer–Source code that is constantly under review allows developers to learn more reliable techniques and best practices.
- Helps teams create better documentation–Code reviews also help teams to create better documentation, which makes it easier for developers to add features and upgrade existing ones in the future.
- Makes QA testing easier–Another benefit of maintaining consistent standards is a source code that is easier for specialists and testers to understand. In Quality Assurance (QA) testing, testers will not only have to check the quality of the code, they will also have to identify issues leading to poor tests. This can lead to persistent, avoidable delays in development due to further testing and reworking.
Although code review offers numerous benefits, it isn’t without its criticism. Some experts argue that code review isn’t compatible with Agile methodologies, though this opinion stems from a misunderstanding regarding how to effectively conduct the review process. In these next few sections, we’ll go over some code review best practices that align with Agile’s iterative sprints without issue.
What are the pillars of code review?
Reflections – If your team has never thought about code health systematically, it’s worth taking it seriously. There are many ways to approach it, but the pillars of code health – maintainability, security, automation, and insights – provide a great framework to think about the problem in your context and start building solutions.
There is no silver bullet to code health, but investing in systems and processes can go a long way. Code health manifests as process, tooling, and code, but it ultimately depends on the people in your team to do the right thing. Engineering leaders must set the tone that code health is everyone’s responsibility.
The most successful teams balance people, processes, and tools in a way that makes everyone happy.
What are the three types of code review?
Types – Code review practices fall into three main categories: pair programming, formal code review and lightweight code review. Formal code review, such as a Fagan inspection, involves a careful and detailed process with multiple participants and multiple phases.
- Formal code reviews are the traditional method of review, in which software developers attend a series of meetings and review code line by line, usually using printed copies of the material.
- Formal inspections are extremely thorough and have been proven effective at finding defects in the code under review.
Lightweight code review typically requires less overhead than formal code inspections, though it can be equally effective when done properly. Lightweight reviews are often conducted as part of the normal development process:
Over-the-shoulder – One developer looks over the author’s shoulder as the latter walks through the code. Email pass-around – Source code management system emails code to reviewers automatically after checkin is made. Pair Programming – Two authors develop code together at the same workstation, such is common in Extreme Programming, Tool-assisted code review – Authors and reviewers use specialized tools designed for peer code review.
Some of these may also be labeled a “Walkthrough” (informal) or “Critique” (fast and informal). Many teams that eschew traditional, formal code review use one of the above forms of lightweight review as part of their normal development process. A code review case study published in the book Best Kept Secrets of Peer Code Review found that lightweight reviews uncovered as many bugs as formal reviews, but were faster and more cost-effective.
What to expect in a code review interview?
Purpose – The candidate is instructed to complete a coding exercise, or bring an existing code sample. As an interviewer, you’ll receive that code at least a day before your interview with the candidate. The focus of the interview should be on their code, how it works, why they made the choices they did, and so forth.
Remember to be as pleasant and friendly as you can be! You can deliver a demanding interview while being kind and empathetic. Whenever possible, ask these questions exactly as they’re worded to try to get consistency between multiple candidates.
What does good code look like?
What Is Good Code? What Does It Look Like? Why Does It Matter? – “Good code” by nature is an evolving practice. For some, good code can mean code that comes with a full suite of unit tests. For others, it can mean implementing composition patterns over inheritance patterns.
- Tests and pattern implementations are debatable components for the definition of “good code” because they are opinionated.
- However, there are certain traits that developers are in consensus about.
- In a nutshell, “good code” is code that is easily accessible and maintainable by the development team.
- This means that comprehension and extensibility are easily achieved by another developer.
The code’s structure and architecture are externalized. It is decoupled from the author and will live longer than the sprint it was created in. In terms of design, “good code” looks orderly, with clear implemented patterns (whatever that pattern may be), and is structured in alignment with conventions rather than invented and for single-use solutions.
How long should a code review take?
How long should a code review really take – ” – A code review should not take hours and hours and hours. Sometimes an implementation change might be a few lines of code and the review takes 10 minutes. Other times, it can take longer. Ideally, the author has submitted a change that adds, deletes or modifies around 400 to 600 lines of code.
If the author’s changes are significant, meaning 1,000 plus lines of code, it’s often better to break the contributions up into multiple submissions. Although sometimes, it’s not possible. Ultimately, you should never spend more than 60 to 90 minutes reviewing another developer’s code because there is a diminishing return.
After 90 minutes, you’ve probably found most, if not all the defects you are able to find. If you still feel unsure, you can always ask another developer on the team to review the code changes or meet with the original author of the code. That being said, you shouldn’t rush a code review.
How strict should code review be?
A successful peer review strategy requires balance between strictly documented processes and a non-threatening, collaborative environment. Highly regimented peer reviews can stifle productivity, yet lackadaisical processes are often ineffective. Managers are responsible for finding a middle ground where peer review can be efficient and effective while fostering open communication and knowledge-share between teammates.
A SmartBear study of a Cisco Systems programming team revealed that developers should review no more than 200 to 400 lines of code (LOC) at a time. The brain can only effectively process so much information at a time; beyond 400 LOC, the ability to find defects diminishes. In practice, a review of 200-400 LOC over 60 to 90 minutes should yield 70-90% defect discovery.
So, if 10 defects existed in the code, a properly conducted review would find between seven and nine of them. It can be tempting to tear through a review, assuming that someone else will catch the errors that you don´t find. However, SmartBear research shows a significant drop in defect density at rates faster than 500 LOC per hour. Code reviews in reasonable quantity, at a slower pace for a limited amount of time results in the most effective code review.
What is the golden rule of code review?
Always remember – it’s a human being on the other end of the review – The first Golden Rule of Code Reviews is simple: Review other people’s code like you’d like your code to be reviewed. Code reviews should:
Be kind – even if there’s room for improvement, the message can be delivered with empathy Be clear – make it easy for the reviewer to understand what you are saying. Importantly, if you have constructive feedback to give, be direct about it. Avoid a “crap sandwich” that starts with positive feedback about the code, even if it’s genuine, before getting to your suggestion for improvement. Be specific – The more granular your feedback can be, the more helpful it is to the Author.
That can be hard to do when so many of us work remotely or hundreds or thousands of miles away from each other. To make sure you are communicating correctly, read your code review to yourself out loud and ask yourself, is this something I would want to be said to me? If not, think about changing the tone or content.
What are the responsibilities of a code reviewer?
The code reviewer role ensures the quality of the source code, and plans and conducts source code reviews. The code reviewer is responsible for any review feedback that recommends necessary rework.
What are the 3 sections of coding technique?
A two-dimensional visualisation of the Hamming distance, a critical measure in coding theory Coding theory is the study of the properties of codes and their respective fitness for specific applications. Codes are used for data compression, cryptography, error detection and correction, data transmission and data storage,
Codes are studied by various scientific disciplines—such as information theory, electrical engineering, mathematics, linguistics, and computer science —for the purpose of designing efficient and reliable data transmission methods. This typically involves the removal of redundancy and the correction or detection of errors in the transmitted data.
There are four types of coding:
- Data compression (or source coding )
- Error control (or channel coding )
- Cryptographic coding
- Line coding
Data compression attempts to remove unwanted redundancy from the data from a source in order to transmit it more efficiently. For example, ZIP data compression makes data files smaller, for purposes such as to reduce Internet traffic. Data compression and error correction may be studied in combination,
Error correction adds useful redundancy to the data from a source to make the transmission more robust to disturbances present on the transmission channel. The ordinary user may not be aware of many applications using error correction. A typical music compact disc (CD) uses the Reed–Solomon code to correct for scratches and dust.
In this application the transmission channel is the CD itself. Cell phones also use coding techniques to correct for the fading and noise of high frequency radio transmission. Data modems, telephone transmissions, and the NASA Deep Space Network all employ channel coding techniques to get the bits through, for example the turbo code and LDPC codes,
Is code review part of Agile?
Agile teams are self-organizing, with skill sets that span across the team. This is accomplished, in part, with code review. Code review helps developers learn the code base, as well as help them learn new technologies and techniques that grow their skill sets.
What is the 3 step coding process?
Other ways to analyze – Open coding, axial coding, and selective coding for grounded theory is just one approach of many ways to analyze qualitative research. To read more about other types of coding, read our Essential Guide to Coding Qualitative Data,
What is a coding checklist?
Code review checklist – A checklist helps you to create a structured approach to code reviews. Also, they remind you of all the quality checks you need to perform to approve code into the codebase. You can include many specific items into your code review checklist. Here’s an overview of must-have items you should always look out for.
What is a review checklist?
Definition: – The Documentation Review Checklist helps you conduct a meaningful review of your documentation pieces, whether you hold technical review meetings and/or send the checklist to individual reviewers. You can customize each line item in the checklist to fit your specific document and review needs.
What should be included in code documentation?
What Is Code Documentation? – Code documentation is the process through which software programmers document their code. It is a combination of clear pictures and textual explanations that describe what a codebase does and how it may be used. It enhances code readability, reproducibility, and usability.