Maintaining clear records of architectural decisions is essential for project success.
Architects and technical leads often must make critical architectural decisions in software development projects that significantly affect development processes and outcomes. The development teams need to understand these decisions, when they take effect and, most importantly, why they were made.
This insight into architectural decisions has become even more essential over the last few years as teams have become increasingly distributed, microservice architectures have grown more complex and with the introduction of generative AI in the coding process.
What is an architecture decision record?
An architecture decision record (ADR) is a document that captures the reasoning behind significant architectural decisions made during a project's lifecycle. With it, developers and architects can review why and in what context a change was made. For example, recording every change made while completely revamping the architecture is essential to keeping the project on track.
An effective ADR provides transparency in the decision-making process and creates a historical record that helps current and future team members understand the evolution of the system architecture. It's a communication tool during the decision process and a reference document afterward.
It's a communication tool during the decision process and a reference document afterward.
Architects or technical leads typically initiate ADRs with input from developers, product owners and other stakeholders. A comprehensive ADR can include the technical aspects of a decision, business constraints, quality attributes addressed and anticipated consequences.
A nonexhaustive list of entries consists of the following:
A clear statement of the architectural decision.
The context and problem being addressed.
Alternatives that were considered.
Decision criteria and constraints.
The implications and consequences of the decision.
Related decisions and dependencies.
The decision status (proposed, accepted, deprecated or superseded).
Best practices for creating architecture decision records
To create a perpetual resource that pays dividends far into the future, architects should follow eight best practices, which include the following:
1. Define the core challenge with situational background
Every ADR begins with pinpointing a specific challenge or requirement. Teams should document the final choice and its context, including team discussions, alternative solutions considered and the post-implementation results.
2. Maintain singular focus per entry
Avoid combining multiple architecture decisions in one document. Each ADR should address one core technical direction or its immediate dependencies. Meanwhile, daily operational calls don't need documentation, strategic choices about frameworks, patterns or infrastructure deserve individual focus.
3. Standardize with flexible templates
Establish consistency with a simple template that teams can adapt as needed. The widely used Michael Nygard framework -- Context/Decision/Consequences -- usually works, while cloud projects might extend this to compliance fields. GitHub hosts numerous examples, from basic markdown formats to AI-assisted templates that help maintain documentation discipline.
While senior architects often initiate ADRs, all developers should understand how to contribute. Implement peer-review practices where experienced team members validate entries from junior staff before finalizing. Emphasize that approved ADRs become a permanent reference and, therefore, subsequent changes require new records that acknowledge previous decisions.
5. Establish clear decision status indicators
An effective ADR system should include clear status indicators for each decision. Common statuses include "Proposed," "Accepted," "Deprecated," and "Superseded." Having explicit status markers helps team members understand which architectural decisions are active, under consideration or replaced by newer decisions. When a decision is superseded, the new ADR should reference the old one and explain why a change was necessary.
6. Include timestamps and version information
Each ADR should be timestamped and, if applicable, include version information about the system or component it affects. This temporal context is essential for understanding the decision as the system evolves. A choice made two years ago might seem puzzling without knowing when it was made and what the system looked like.
7. Implement a systematic review process
Establish a regular review process for proposed architecture decisions before they become officially accepted. This review should involve key stakeholders, architects, senior developers and sometimes product owners or other business representatives. The review process ensures that architectural decisions are thoroughly vetted, align with the overall system vision, and account for significant technical and business constraints.
8. Store ADRs with your codebase
Keep your ADRs close to your code, ideally in your application's version control system. This proximity ensures that ADRs are versioned alongside the code they describe, making them easily accessible to developers. A common practice is to store ADRs in a designated directory such as "docs/adr/" or "architecture/decisions/" within your repository.
Benefits of maintaining architecture decision records
Implementing an ADR system has several advantages, including the following:
Knowledge retention. ADRs create an institutional memory that outlives individual team members, capturing nuanced context that traditional documentation often misses. This becomes particularly valuable during team transitions -- when a senior architect departs, their decision rationale doesn't leave with them.
Decision transparency. By explicitly documenting the why behind choices, ADRs prevent the common pitfall of "decision amnesia" where teams revisit settled debates. This transparency builds stakeholders' trust and creates an audit trail for compliance.
Better collaboration and alignment. The structured ADR format forces teams to consider alternatives and tradeoffs explicitly, leading to more deliberate decision-making.
Accelerated incident resolution. ADRs provide context for system design choices during production incidents.
Reusable resource. Well-structured ADRs become valuable assets beyond individual projects. Organizations can mine these records for patterns and reusable solutions, accelerating similar initiatives.
Future-proofing architectural evolution. ADRs help teams anticipate technical debt and plan strategic refactoring by maintaining a decision timeline. Explicitly recording deprecated decisions and their replacements creates a clear migration path for legacy systems.
Architecture decision record tools
Several tools can support the creation and management of ADRs, including the following:
ADR Manager. A web-based tool that helps teams create, manage and visualize ADRs.
ADR Tools. A command-line tool for working with ADRs in Markdown format, helping teams create, manage and link ADRs efficiently.
Backstage ADR plugin. This plugin provides ADR management within the developer portal for teams using Spotify's Backstage.
Dotnet-adr. A .NET global tool for creating and managing ADRs using various templates.
Log4brains. An open source tool that provides a static site generator for ADRs, making them easily browsable and searchable.
Pyadr. A Python tool for managing the ADR lifecycle, including proposal, acceptance, rejection and superseding processes.
Visual Studio Code extensions. Several extensions exist for VS Code that provide templates and tools for working with ADRs.
Regardless of the chosen tool, architecture decision records are an essential practice for modern software development teams. By documenting the context, alternatives, decisions, and consequences of architectural choices, teams can maintain knowledge, improve communication, and ensure that future development remains aligned with the architectural vision.
Editor's note: This article was originally published in 2020 and was updated in 2025 to expand the list of best practices and provide a list of architecture decision record tools.
Twain Taylor is a technical writer, musician and runner. Having started his career at Google in its early days, today, Twain is an accomplished tech influencer. He works closely with startups and journals in the cloud-native space.
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Maintaining clear records of architectural decisions is essential for project success.
Architects and technical leads often must make critical architectural decisions in software development projects that significantly affect development processes and outcomes. The development teams need to understand these decisions, when they take effect and, most importantly, why they were made.
This insight into architectural decisions has become even more essential over the last few years as teams have become increasingly distributed, microservice architectures have grown more complex and with the introduction of generative AI in the coding process.
What is an architecture decision record?
An architecture decision record (ADR) is a document that captures the reasoning behind significant architectural decisions made during a project's lifecycle. With it, developers and architects can review why and in what context a change was made. For example, recording every change made while completely revamping the architecture is essential to keeping the project on track.
An effective ADR provides transparency in the decision-making process and creates a historical record that helps current and future team members understand the evolution of the system architecture. It's a communication tool during the decision process and a reference document afterward.
Architects or technical leads typically initiate ADRs with input from developers, product owners and other stakeholders. A comprehensive ADR can include the technical aspects of a decision, business constraints, quality attributes addressed and anticipated consequences.
A nonexhaustive list of entries consists of the following:
A clear statement of the architectural decision.
The context and problem being addressed.
Alternatives that were considered.
Decision criteria and constraints.
The implications and consequences of the decision.
Related decisions and dependencies.
The decision status (proposed, accepted, deprecated or superseded).
Best practices for creating architecture decision records
To create a perpetual resource that pays dividends far into the future, architects should follow eight best practices, which include the following:
1. Define the core challenge with situational background
Every ADR begins with pinpointing a specific challenge or requirement. Teams should document the final choice and its context, including team discussions, alternative solutions considered and the post-implementation results.
2. Maintain singular focus per entry
Avoid combining multiple architecture decisions in one document. Each ADR should address one core technical direction or its immediate dependencies. Meanwhile, daily operational calls don't need documentation, strategic choices about frameworks, patterns or infrastructure deserve individual focus.
3. Standardize with flexible templates
Establish consistency with a simple template that teams can adapt as needed. The widely used Michael Nygard framework -- Context/Decision/Consequences -- usually works, while cloud projects might extend this to compliance fields. GitHub hosts numerous examples, from basic markdown formats to AI-assisted templates that help maintain documentation discipline.
While senior architects often initiate ADRs, all developers should understand how to contribute. Implement peer-review practices where experienced team members validate entries from junior staff before finalizing. Emphasize that approved ADRs become a permanent reference and, therefore, subsequent changes require new records that acknowledge previous decisions.
5. Establish clear decision status indicators
An effective ADR system should include clear status indicators for each decision. Common statuses include "Proposed," "Accepted," "Deprecated," and "Superseded." Having explicit status markers helps team members understand which architectural decisions are active, under consideration or replaced by newer decisions. When a decision is superseded, the new ADR should reference the old one and explain why a change was necessary.
6. Include timestamps and version information
Each ADR should be timestamped and, if applicable, include version information about the system or component it affects. This temporal context is essential for understanding the decision as the system evolves. A choice made two years ago might seem puzzling without knowing when it was made and what the system looked like.
7. Implement a systematic review process
Establish a regular review process for proposed architecture decisions before they become officially accepted. This review should involve key stakeholders, architects, senior developers and sometimes product owners or other business representatives. The review process ensures that architectural decisions are thoroughly vetted, align with the overall system vision, and account for significant technical and business constraints.
8. Store ADRs with your codebase
Keep your ADRs close to your code, ideally in your application's version control system. This proximity ensures that ADRs are versioned alongside the code they describe, making them easily accessible to developers. A common practice is to store ADRs in a designated directory such as "docs/adr/" or "architecture/decisions/" within your repository.
Benefits of maintaining architecture decision records
Implementing an ADR system has several advantages, including the following:
Knowledge retention. ADRs create an institutional memory that outlives individual team members, capturing nuanced context that traditional documentation often misses. This becomes particularly valuable during team transitions -- when a senior architect departs, their decision rationale doesn't leave with them.
Decision transparency. By explicitly documenting the why behind choices, ADRs prevent the common pitfall of "decision amnesia" where teams revisit settled debates. This transparency builds stakeholders' trust and creates an audit trail for compliance.
Better collaboration and alignment. The structured ADR format forces teams to consider alternatives and tradeoffs explicitly, leading to more deliberate decision-making.
Accelerated incident resolution. ADRs provide context for system design choices during production incidents.
Reusable resource. Well-structured ADRs become valuable assets beyond individual projects. Organizations can mine these records for patterns and reusable solutions, accelerating similar initiatives.
Future-proofing architectural evolution. ADRs help teams anticipate technical debt and plan strategic refactoring by maintaining a decision timeline. Explicitly recording deprecated decisions and their replacements creates a clear migration path for legacy systems.
Architecture decision record tools
Several tools can support the creation and management of ADRs, including the following:
ADR Manager. A web-based tool that helps teams create, manage and visualize ADRs.
ADR Tools. A command-line tool for working with ADRs in Markdown format, helping teams create, manage and link ADRs efficiently.
Backstage ADR plugin. This plugin provides ADR management within the developer portal for teams using Spotify's Backstage.
Dotnet-adr. A .NET global tool for creating and managing ADRs using various templates.
Log4brains. An open source tool that provides a static site generator for ADRs, making them easily browsable and searchable.
Pyadr. A Python tool for managing the ADR lifecycle, including proposal, acceptance, rejection and superseding processes.
Visual Studio Code extensions. Several extensions exist for VS Code that provide templates and tools for working with ADRs.
Regardless of the chosen tool, architecture decision records are an essential practice for modern software development teams. By documenting the context, alternatives, decisions, and consequences of architectural choices, teams can maintain knowledge, improve communication, and ensure that future development remains aligned with the architectural vision.
Editor's note: This article was originally published in 2020 and was updated in 2025 to expand the list of best practices and provide a list of architecture decision record tools.
Twain Taylor is a technical writer, musician and runner. Having started his career at Google in its early days, today, Twain is an accomplished tech influencer. He works closely with startups and journals in the cloud-native space.
