The Review Process

The review of architectures needs to be done in a consistent manner, with a blame-free approach that encourages diving deep. It should be a light weight process (hours not days) that is a conversation and not an audit. The purpose of reviewing an architecture is to identify any critical issues that might need addressing or areas that could be improved. The outcome of the review is a set of actions that should improve the experience of a customer using the workload.

As discussed in the “On Architecture” section, you will want each team member to take responsibility for the quality of its architecture. We recommend that the team members who build an architecture use the Well-Architected Framework to continually review their architecture, rather than holding a formal review meeting. A continuous approach allows your team members to update answers as the architecture evolves, and improve the architecture as you deliver features.

The AWS Well-Architected Framework is aligned to the way that AWS reviews systems and services internally. It is premised on a set of design principles that influences architectural approach, and questions that ensure that people don’t neglect areas that often featured in Root Cause Analysis (RCA). Whenever there is a significant issue with an internal system, AWS service, or customer, we look at the RCA to see if we could improve the review processes we use.

Reviews should be applied at key milestones in the product lifecycle, early on in the design phase to avoid one-way doors« [ Many decisions are reversible, two-way doors. Those decisions can use a light weight process. One-way doors are hard or impossible to reverse and require more inspection before making them. ] »  that are difficult to change, and then before the go-live date. After you go into production, your workload will continue to evolve as you add new features and change technology implementations. The architecture of a workload changes over time. You will need to follow good hygiene practices to stop its architectural characteristics from degrading as you evolve it. As you make significant architecture changes you should follow a set of hygiene processes including a Well-Architected review.

If you want to use the review as a one-time snapshot or independent measurement, you will want to ensure that you have all the right people in the conversation. Often, we find that reviews are the first time that a team truly understands what they have implemented. An approach that works well when reviewing another team's workload is to have a series of informal conversations about their architecture where you can glean the answers to most questions. You can then follow up with one or two meetings where you can gain clarity or dive deep on areas of ambiguity or perceived risk.

Here are some suggested items to facilitate your meetings:

• A meeting room with whiteboards

• Print outs of any diagrams or design notes

• Action list of questions that require out-of-band research to answer (for example, did we enable encryption or not?)

After you have done a review, you should have a list of issues that you can prioritize based on your business context. You will also want to take into account the impact of those issues on the day-to-day work of your team. If you address these issues early, you could free up time to work on creating business value rather than solving recurring problems. As you address issues, you can update your review to see how the architecture is improving.

While the value of a review is clear after you have done one, you may find that a new team might be resistant at first. Here are some objections that can be handled through educating the team on the benefits of a review:

• We are too busy! (Often said when the team is getting ready for a big launch.)

  • If you are getting ready for a big launch you will want it to go smoothly. The review will allow you to understand any problems you might have missed.

  • We recommend that you carry out reviews early in the product lifecycle to uncover risks and develop a mitigation plan aligned with the feature delivery roadmap.

• We don’t have time to do anything with the results! (Often said when there is an immovable event, such as the Super Bowl, that they are targeting.)

  • These events can’t be moved. Do you really want to go into it without knowing the risks in your architecture? Even if you don’t address all of these issues you can still have playbooks for handling them if they materialize

• We don’t want others to know the secrets of our solution implementation!

  • If you point the team at the questions in the Well-Architected Framework, they will see that none of the questions reveal any commercial or technical propriety information.

As you carry out multiple reviews with teams in your organization, you might identify thematic issues. For example, you might see that a group of teams has clusters of issues in a particular pillar or topic. You will want to look at all your reviews in a holistic manner, and identify any mechanisms, training, or principal engineering talks that could help address those thematic issues.