8 Best Code Review Practices to Implement in 2025

Code review is a cornerstone of modern software development, acting as the critical quality gate that separates good code from great code. Done right, it fosters collaboration, spreads knowledge, and catches bugs before they impact users. However, a poorly managed review process can become a major bottleneck, leading to developer frustration, context switching, and stalled projects. The difference between a high-performing engineering team and an average one often lies in their approach to this crucial practice.

This guide moves beyond generic advice to provide a detailed, itemized collection of actionable strategies. We will dive into eight of the best code review practices that elite teams use to transform their reviews from a tedious chore into a powerful accelerator. You will learn how to structure pull requests for maximum clarity, leverage automation to catch errors early, and provide feedback that builds skills rather than resentment. Each point is designed to be immediately implementable, helping you refine your workflow and improve team velocity.

These strategies cover the entire review lifecycle, from author submission to final approval. To dive deeper into the overarching principles, you can discover more code review best practices that cover various aspects of the development cycle. By implementing the techniques outlined below, you can eliminate common friction points, establish clear expectations, and ensure your review process is a value-add, not a roadblock. Let's explore how to build a culture of engineering excellence and ship better software, faster.

1. Keep Pull Requests Small and Focused

One of the most impactful and universally accepted best code review practices is to keep your pull requests (PRs) small and focused. This principle dictates that each PR should address a single, well-defined concern, such as a bug fix, a small feature implementation, or a specific refactoring task. By limiting the scope, you transform a potentially overwhelming review into a manageable and efficient process.

Large PRs, often called "monster PRs," are a notorious source of friction in development workflows. They increase the cognitive load on reviewers, making it difficult to spot subtle bugs, logical flaws, or deviations from coding standards. Research from companies like Atlassian and SmartBear has consistently shown that as the size of a change increases, the quality of the review decreases significantly. A reviewer is far more likely to provide a thorough, line-by-line analysis on a 150-line PR than they are on a 1,500-line one.

Why It's a Top Practice

The benefits of small PRs extend beyond just review quality. This approach accelerates the entire development lifecycle. Smaller changes are merged faster, which reduces the risk of merge conflicts and keeps the main branch up-to-date. This also means features and fixes are deployed to production more frequently, leading to a tighter feedback loop with users.

Industry leaders have long championed this approach. For example, Google's internal engineering guidelines famously advocate for small, atomic changes. Microsoft's own development teams often recommend keeping PRs under 400 lines of code to maintain review effectiveness.

How to Implement This Practice

Adopting a small PR mindset requires discipline and a few key strategies:

• Separate Refactoring from Features: If you need to refactor existing code before adding a new feature, do it in a separate PR. Combining the two makes it hard for reviewers to distinguish between structural improvements and new logic.
• Use Feature Flags: For large features that can't be completed in a single small PR, use feature flags. This allows you to merge incomplete or partially developed code into the main branch without exposing it to users. The feature can be built incrementally across multiple small, focused PRs.
• Leverage Stacked Diffs: Pioneered by teams at companies like Shopify, stacked diffs (or stacked PRs) involve creating a series of small, dependent PRs. Each PR in the stack builds upon the previous one, allowing a large feature to be reviewed in logical, digestible chunks.
• Utilize Draft PRs: For work that is still in progress, open a draft or "Work in Progress" (WIP) PR. This signals to your team that the code isn't ready for final review but allows you to get early feedback on your approach, preventing significant rework later on.

2. Write Clear, Descriptive PR Descriptions

While the code itself tells the story of how a change is implemented, it often fails to explain the what and the why. This is where clear, descriptive pull request (PR) descriptions become an essential component of the best code review practices. A well-written description provides crucial context, turning a code review from a simple syntax check into a meaningful discussion about problem-solving and architectural decisions. It serves as both a guide for the reviewer and a form of living documentation for future developers.

A sparse or empty PR description forces reviewers to become detectives, piecing together the purpose of the changes by reverse-engineering the code. This significantly increases their cognitive load and the time required for the review, often leading to superficial feedback that misses the bigger picture. In contrast, a comprehensive description equips them with the necessary background to provide targeted, high-quality feedback efficiently.

Why It's a Top Practice

A strong PR description streamlines the entire review process. It preemptively answers questions reviewers might have, clarifies the intent behind the code, and highlights potential areas of concern. This practice is a cornerstone of effective asynchronous communication, allowing development to proceed smoothly even across different time zones.

This emphasis on context is championed by leading engineering cultures. For example, GitHub's own teams rely heavily on detailed PR templates to structure descriptions. Stripe's engineering culture often encourages 'Request for Comments' (RFC) style PRs for significant changes, where the description outlines the problem, the proposed solution, and alternatives considered. This approach ensures that the rationale behind every change is captured and understood.

How to Implement This Practice

Systematically improving your PR descriptions is straightforward with a few established techniques:

• Use PR Templates: Most Git platforms (like GitHub, GitLab, and Bitbucket) support PR templates. Create a template in your repository that prompts authors to fill out key sections like "Problem," "Solution," "How to Test," and "Relevant Tickets." This ensures consistency and completeness.
• Include Visual Aids: For any UI changes, a picture is worth a thousand lines of code. Include before-and-after screenshots or GIFs to make the impact of your changes immediately clear to reviewers.
• Explain Your Decisions: If you made a specific trade-off or considered alternative approaches, briefly explain why you chose the current implementation. This demonstrates critical thinking and helps reviewers understand the constraints you were working with.
• Link to Supporting Documents: If the PR relates to a specific ticket, design document, or user story, include a link. This gives reviewers easy access to the full context if they need to dig deeper.

3. Implement Automated Checks Before Human Review

One of the most effective ways to streamline the code review process is to delegate repetitive, mechanical checks to automated tools. This practice involves setting up a continuous integration (CI) pipeline that automatically runs checks for code style, syntax errors, and test failures on every pull request. By catching these common issues before a human ever sees the code, you free up your reviewers to concentrate on what they do best: assessing logic, design, architecture, and complex problem-solving.

Automating these foundational checks saves an enormous amount of time and reduces cognitive friction for everyone involved. Instead of reviewers leaving comments about missing semicolons or incorrect indentation, the conversation can focus on higher-level concerns that truly impact the quality and maintainability of the software. This approach transforms the code review from a tedious proofreading exercise into a valuable architectural discussion.

Why It's a Top Practice

Automated checks serve as a quality gate, ensuring a baseline standard for every contribution. This is a core component of modern DevOps and is considered a fundamental best code review practice by engineering organizations worldwide. Companies like Google and Netflix rely heavily on extensive CI/CD practices to maintain velocity and quality at scale. Facebook's open-source static analyzer, Infer, automatically detects critical bugs like null pointer exceptions and resource leaks in C++, Java, and Objective-C, preventing them from ever reaching human review.

This practice also fosters a culture of ownership. When a CI pipeline fails, the author is immediately notified and can fix the issues independently. This instant feedback loop is far more efficient than waiting for a human reviewer to spot and report the same problems.

How to Implement This Practice

Integrating automated checks into your workflow can be done incrementally and yields immediate benefits:

• Start with Linting and Formatting: Begin by adding basic tools like ESLint and Prettier for JavaScript or Black for Python. These tools enforce consistent coding styles and catch simple syntax errors, providing a quick and easy win.
• Enforce Checks with Branch Protection: Use branch protection rules in platforms like GitHub or GitLab to require that all automated checks pass before a PR can be merged. This makes adherence to standards non-negotiable.
• Make CI Failures Actionable: Ensure that the output from your automated tools is clear and easy to understand. Error messages should point directly to the problematic file and line number and, if possible, suggest a fix.
• Enable Local Execution: Allow developers to run the exact same checks on their local machines before pushing code. This empowers them to catch and fix issues early, preventing broken builds and unnecessary CI runs.
• Gradually Add More Sophisticated Checks: Once the basics are in place, introduce more advanced tools like static analysis for security vulnerabilities (e.g., Snyk, SonarQube), dependency checkers, and code coverage reporters to continuously enhance your quality gate.

4. Focus on High-Impact Issues During Review

One of the most effective best code review practices is to prioritize your feedback, concentrating on high-impact issues rather than getting bogged down by trivialities. This means reviewers should channel their energy into identifying and commenting on potential logic errors, security vulnerabilities, architectural inconsistencies, and performance bottlenecks. Minor stylistic preferences should take a backseat to issues that could genuinely affect the application's stability, security, or maintainability.

Not all feedback is created equal. A comment suggesting a variable rename is far less critical than one pointing out a potential SQL injection vulnerability or an unhandled edge case that could crash the system. When reviewers flood a pull request with low-impact comments, it creates noise and can dilute the importance of the more critical feedback. This can lead to "comment fatigue" for the author, where crucial points are lost in a sea of minor suggestions.

Why It's a Top Practice

Adopting a high-impact focus makes the code review process more efficient and valuable for everyone involved. It ensures that the most critical risks are addressed before code is merged, directly improving software quality and security. This approach respects the author's time by helping them prioritize their revisions and avoids lengthy, unproductive debates over subjective style choices, which are better handled by automated tools.

This principle is a cornerstone of mature engineering cultures. For example, Microsoft's Security Development Lifecycle (SDL) mandates rigorous, security-focused code reviews to catch vulnerabilities early. Similarly, practices promoted by OWASP emphasize scrutinizing code for common security flaws, treating these as the highest-priority findings during any review.

How to Implement This Practice

Effectively focusing on what matters requires a systematic approach and clear team alignment:

• Automate Style and Linting: The most effective way to eliminate low-impact comments is to automate style enforcement. Use tools like ESLint, Prettier, or RuboCop to automatically format code and flag stylistic issues in the CI/CD pipeline. This removes the need for humans to comment on spacing, naming, or formatting.
• Use a Review Checklist: Create and share a checklist that guides reviewers to look for specific high-impact areas. This could include checks for proper error handling, security vulnerabilities (like those in the OWASP Top 10), performance implications, and adherence to architectural patterns.
• Introduce Severity Labels: Encourage reviewers to label their comments by severity (e.g., [Critical], [Suggestion], [Question]). This helps the author immediately understand which comments are non-negotiable fixes and which are suggestions for consideration.
• Assess the "Blast Radius": When reviewing, always consider the potential "blast radius" of a potential bug. A flaw in a core authentication module is far more critical than a UI bug on a rarely visited settings page. Prioritize your feedback accordingly.

5. Provide Constructive, Actionable Feedback

The quality of a code review is defined not just by the technical issues it catches, but by the way feedback is delivered. One of the most critical code review practices is to ensure all comments are constructive and actionable. This means focusing on the code itself, not the author, and providing guidance that is specific, helpful, and aimed at fostering growth and collaboration. The goal is to improve the codebase while empowering the developer.

Blunt or vague feedback can create a defensive atmosphere, discouraging developers from taking risks or seeking reviews. In contrast, a culture of constructive feedback transforms the code review from a gatekeeping process into a mentorship opportunity. It builds psychological safety, encouraging open communication and shared ownership of code quality. This approach elevates the entire team's skills over time.

Why It's a Top Practice

Adopting a constructive feedback model directly impacts team morale, velocity, and code quality. When developers receive feedback that helps them understand why a change is needed and how to implement it, they learn more effectively. This reduces the number of back-and-forth cycles on a pull request, leading to faster merge times.

This philosophy is a cornerstone of high-performing engineering cultures. Google's internal engineering guide, "How to do a code review," heavily emphasizes respectful and constructive communication. Similarly, Spotify’s engineering culture promotes blameless feedback, focusing on systemic improvements rather than individual errors. Thought leaders like Sarah Drasner have also championed this approach as essential for building inclusive and effective engineering teams.

How to Implement This Practice

Mastering constructive feedback involves being mindful of language and intent. Here are several actionable strategies:

• Frame Comments as Suggestions, Not Demands: Instead of "Fix this," try "What do you think about handling the null case here?" This opens a dialogue rather than issuing a command.
• Explain the 'Why': Don't just point out a problem. Explain the reasoning behind your suggestion, linking it to performance, readability, or maintainability. For example, "Using a Set here instead of an Array would give us O(1) lookups, which will be more performant as this list grows."
• Balance Critique with Praise: Acknowledge what the author did well. A simple "Great use of the new API here!" can make constructive criticism easier to receive and shows you're engaged with the entire change.
• Offer to Pair Program: For particularly complex or nuanced feedback, offer to jump on a call or pair program. This is often faster and more collaborative than a lengthy comment thread. You can learn more by reading the ultimate guide to constructive feedback in code reviews.

6. Establish Clear Review Criteria and Standards

One of the most foundational best code review practices is to establish clear, documented criteria for what constitutes a "good" review. Without shared standards, code reviews become subjective, inconsistent, and can lead to friction between team members. By defining what reviewers should look for, you create a unified benchmark for quality, making the entire process more objective, efficient, and educational for everyone involved.

When expectations are ambiguous, reviewers may focus on trivial stylistic preferences while missing critical logic flaws, or authors may feel that feedback is arbitrary. Clear standards empower both sides of the process. Authors know what to aim for before they even open a pull request, and reviewers have a concrete framework to guide their feedback, ensuring that all submissions are evaluated consistently and fairly.

Why It's a Top Practice

Defining review criteria directly addresses the root cause of many common code review problems: inconsistency and subjectivity. It ensures that every PR is evaluated against the same high bar for correctness, readability, security, and performance. This consistency is crucial for maintaining a healthy and scalable codebase over the long term.

This approach has been famously championed by tech giants. Google's comprehensive Style Guides are legendary, providing language-specific rules that eliminate debates over formatting and conventions. Similarly, Airbnb's JavaScript Style Guide has become an industry standard, adopted by countless organizations to enforce clean, maintainable code. These companies prove that a shared understanding of "good" is a prerequisite for engineering excellence.

How to Implement This Practice

Creating and maintaining review standards is a collaborative team effort. Here’s how to get started:

• Start with an Industry Standard: Don't reinvent the wheel. Adopt a well-regarded guide like Google's or Airbnb's as a baseline, and then customize it to fit your team's specific needs and technologies.
• Document Everything in One Place: Your standards should be easily accessible, searchable, and centrally located (e.g., in a team wiki or repository). Include specific examples of "good" and "bad" patterns to make the guidelines tangible.
• Create a Code Review Checklist: A checklist is a powerful tool to ensure key criteria are never overlooked. A well-structured checklist guides reviewers to check for things like logic, test coverage, security vulnerabilities, and documentation. You can learn more about creating an effective code review checklist on pullnotifier.com.
• Iterate and Update: Standards are not set in stone. Hold regular team meetings to discuss, refine, and update your guidelines based on new challenges, technologies, or lessons learned. This keeps them relevant and ensures team buy-in.

7. Use Appropriate Review Assignment and Rotation

Strategically assigning reviewers is a cornerstone of an effective and scalable code review process. This practice moves beyond randomly picking teammates and instead involves assigning reviews based on expertise, availability, and opportunities for knowledge sharing. By implementing a system of thoughtful assignment and rotation, teams can prevent bottlenecks, distribute workloads evenly, and foster a culture of collective code ownership.

Simply assigning the same senior developer to every critical review creates a single point of failure and burns out your most experienced engineers. A balanced approach ensures that the right eyes are on the right code without overwhelming any single individual. This method improves both the speed and quality of reviews, making it one of the most impactful best code review practices for growing teams.

Why It's a Top Practice

The primary benefit is the democratization of knowledge. When review responsibilities are rotated, more team members become familiar with different parts of the codebase. This reduces the "bus factor" and empowers junior developers to grow their skills by learning from senior-authored code. Furthermore, it ensures that review feedback is diverse, as different engineers bring unique perspectives and catch different types of issues.

Tech giants have built entire systems around this principle. Facebook's internal review tools suggest reviewers based on code ownership history, while Uber employs differential review assignments that require more or fewer reviewers based on the change's assessed risk. GitHub's CODEOWNERS file directly operationalizes this concept, allowing teams to codify who is responsible for which parts of the application.

How to Implement This Practice

Integrating strategic review assignment into your workflow can be done through a combination of automation and team agreements:

• Maintain a CODEOWNERS File: This is the simplest and most effective first step. A CODEOWNERS file in your repository automatically assigns specific individuals or teams as reviewers when changes are made to the files they own. You can learn more about how to automatically assign reviewers in GitHub to streamline this process.
• Balance Workload Consciously: Use tools or simple team tracking to monitor review load. If one person is consistently getting swamped with reviews, manually re-assign some to other qualified team members to ensure fairness and prevent burnout.
• Pair Juniors with Seniors: Intentionally pair a junior developer with a senior on reviews. The senior can provide a deep technical critique, while the junior can check for clarity, documentation, and adherence to team conventions, all while learning the codebase.
• Establish a Review Rota: For general reviews that don't fall under a specific code owner, use a weekly rotation or a "round-robin" system. This ensures everyone participates and keeps the responsibility distributed.
• Consider Time Zones: For distributed teams, assign at least one reviewer from a different time zone. This can facilitate "follow-the-sun" reviews, minimizing wait times and accelerating the development cycle.

8. Establish Response Time Expectations and SLAs

One of the most effective ways to prevent code review from becoming a development bottleneck is to establish clear response time expectations and Service Level Agreements (SLAs). This practice involves setting and communicating team-wide goals for how quickly code should be picked up for review and how long the entire process should take, from PR submission to merge. It transforms the often ambiguous "when you get a chance" review culture into a predictable and efficient system.

Without explicit timelines, pull requests can languish for days, blocking features, frustrating authors, and creating a cascade of delays. By defining clear SLAs, you provide reviewers with a concrete goal and authors with a reliable timeframe, ensuring that one of the most critical parts of the development workflow remains swift and consistent. This is a cornerstone of many high-performing engineering organizations that value a rapid feedback loop.

Why It's a Top Practice

The primary benefit of review SLAs is that they directly address and mitigate the "time to merge" problem. When code sits in a pending state, it's not delivering value. This practice is heavily endorsed by the principles outlined in the Accelerate book and the DORA (DevOps Research and Assessment) metrics, which correlate shorter cycle times with elite engineering performance.

Industry leaders have demonstrated the power of this approach. Google’s widely cited engineering practices advocate for a review turnaround time of one business day. Similarly, companies like Shopify and Linear implement strict internal SLAs, often as short as four hours for standard changes, and use dashboards to track adherence. This focus on speed ensures that momentum is maintained and the development cycle keeps flowing smoothly.

How to Implement This Practice

Successfully implementing review SLAs requires team buy-in and a structured approach:

• Set Realistic, Tiered SLAs: Don't apply a one-size-fits-all rule. Establish different SLAs for different types of changes. For example, a critical hotfix might require a 1-hour response time, a small feature might have a 4-hour SLA, and a larger, non-urgent refactor could have a 24-hour SLA.
• Use Automation for Reminders: Integrate tools that automatically nudge reviewers when a PR is approaching its SLA breach. Slack bots or GitHub Actions can send gentle reminders to the assigned reviewers or the wider team channel, taking the burden off the PR author.
• Track and Visualize Metrics: Create dashboards to monitor key metrics like "Time to First Review" and "Total PR Merge Time." Visualizing this data helps identify bottlenecks, celebrate successes, and hold the team accountable to the agreed-upon standards.
• Include Review Time in Sprint Planning: Acknowledge that code review is a crucial part of the development work. Allocate specific capacity for reviewing code during sprint planning to ensure engineers have the bandwidth to meet the established SLAs without sacrificing their own tasks.

Best Practices Comparison Matrix

Supercharge Your Workflow with Smarter Notifications

We've explored a comprehensive suite of strategies designed to transform your code review process from a necessary chore into a powerful engine for quality and collaboration. By breaking down pull requests into small, digestible units and crafting crystal-clear descriptions, you set the stage for success. Layering in automated checks and establishing clear review criteria ensures that human effort is directed where it matters most: on the high-impact issues that define a robust and maintainable codebase.

The journey doesn't end with process, however. The human element, governed by constructive feedback, clear response time expectations, and fair review assignments, is what truly elevates a team's performance. Mastering these best code review practices isn't just about catching bugs; it's a cultural investment that pays dividends in team cohesion, shared knowledge, and a collective sense of ownership over the product.

From Good Practices to a Great System

Adopting these practices individually will yield positive results. A team that masters small PRs will move faster. A team that gives better feedback will foster a healthier culture. But the true, transformative power emerges when these elements are woven together into a cohesive, well-oiled system.

Think of it as an assembly line for quality. Each stage, from PR creation to final merge, is optimized for efficiency and effectiveness.

• Small PRs are the raw materials, easy to handle and inspect.
• Clear descriptions are the blueprints, ensuring everyone understands the intent.
• Automated checks are the initial quality control, filtering out predictable flaws.
• Focused human review is the expert craftsmanship, adding nuance and insight.
• Constructive feedback is the continuous improvement loop, refining both the code and the developers.

When this system flows without friction, developers can maintain deep focus, context switching is minimized, and the entire delivery pipeline accelerates. The key to achieving this seamless flow lies in mastering the final, often-overlooked component: communication and notification management.

The Final Piece of the Puzzle: Eliminating Notification Noise

Even the most perfect code review process can grind to a halt due to poor communication flow. Developers waste precious mental energy constantly checking GitHub for updates, while important review requests get lost in a sea of noisy email or Slack notifications. This is where a dedicated, intelligent notification system becomes indispensable.

Waiting for a review or wondering if your feedback has been addressed creates costly delays and breaks a developer's concentration. The goal is to make the entire process feel effortless and immediate. Instead of forcing your team to pull information by constantly checking statuses, the right information should be pushed to the right people at the exact moment they need it.

This is the final step in operationalizing the best code review practices we've discussed. You've defined the what and the how; now it's time to perfect the when. By automating the communication layer, you ensure that the momentum gained from small PRs and clear guidelines isn't lost to avoidable waiting periods. This turns your well-defined process into a high-velocity, dynamic workflow, empowering your team to merge higher-quality code, faster.

Ready to eliminate notification chaos and keep your development team in the flow? PullNotifier integrates directly with your workflow, delivering smart, real-time pull request updates to Slack so your team can focus on what they do best. Start your free trial of PullNotifier today and see how effortless a streamlined code review process can be.