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AppEng Decision Process

Application Engineers are staffed sparsely across projects at Truss. This means engineers are often working on unrelated products, code bases and technologies. Because of this, we've created some intentional structure to facilitate decision making, share what has/hasn't gone well, and incorporate common patterns into our main playbook. Due to the variance in projects, we don't expect a one-size-fits-all mentality to decision making. However, we do hope to account for some prominent cases and highlight when certain applications make sense.

How to Make a Decision

At it's core decision making process is as follows:

  1. Identify a decision made on a project that is applicable to the whole practice.
  2. Write an Architectural Decision Record (ADR) justifying it.
  3. Workshop the ADR with a Domain Group and create a final draft.
  4. Propose it in Slack for all of AppEng for review.
  5. (Optional) Hold a meeting for review.
  6. Commit the ADR and create implementation documentation.

Writing an ADR

ADRs are a lightweight format that allows us to identify use cases and solutions for problems we face in our engineering. In AppEng, we're incorporating ADRs into our practice because they're the format we commonly communicate with, advocate for, and have had success with on projects.

On the practice level, decision records may look different than those on projects. While the end result may be similar, the justification may require further elaboration around why this decision may benefit as a whole. More specifically, what common use case or pattern may this solve for. (TODO: add guide/clarity on how to do this along with initial examples that demonstrate it)

More information around process and structure for ADRs can be found in the Architecural Decision Records section of the playbook.

Domain Groups

In order to organize members across projects, we've established domain groups that have responsibility over a certain part of the stack. Currently these are broken up into:

  • Frontend - For decisions around browser technology, frontend frameworks, and client side data modeling.
  • Server - For decisions that deal with database modeling, processing, and general API building.
  • General(better name please) - For decisions that fall outside of the other two groups or heavily incorporate both. This will likely be broken out into other groups as we discover what topics come up.

While guilds are established as topical and cross practice, domain groups that overlap with guilds may choose to use their time to prompt new ADRs, workshop, or review them. These are not explicitly 1:1 in overlap and leadership structures are not synonymous.

Group Leaders

Groups leaders are accountable for moving forward their group's decisions. They should seek to delegate and create alignment among the group, however end decision making power lies with them. One leader will be assigned per group, and serve a six month term. Practice leadership will call for nominees from the practice and pick leaders in between those terms. Group leaders should be at a minimum level 3 and have established specialization within their group's domain. They should also have a year experience at Truss.

Group leaders are also responsible for connecting practice members with domain experts that can help them craft decisions best and reviewers to provide feedback. Their motivation should be to create a collaborative experience and effective group output.

The rough expectation for time from a group leader is one hour per week.

Review Meetings

If a decision is contested or requires syncronous clarification, a review meeting should happen. The author of the ADR is responsible for scheduling the meeting and announcing it to #appeng for attendance. The author, domain group leader, and reviewers should be in attendance.

Review meetings should happen at earliest two weeks after an ADR is announced. This isn't to say folks can't collaborate earlier, but having asyncronous time to review and incorporate feedback is helpful.

If a clear consensus can be found during the meeting, the domain group leader for the decision may move it forward. Otherwise, the domain group leader is responsible for following up with the ADR author and establishing deciders/decision making criteria. The group leader may delegate decision power, but is accountable for a decision no later than one week after the meeting.


Once a decision is made, there are three follow ups required:

  1. Commit the ADR.
  2. Announce the decision in #appeng.
  3. Write implementation documentation in this playbook.

ADRs authors are responsible for the corresponding documentation. Practice leadership will check in on recent ADRs to ensure documentation has been written to reflect the decision.

Project Implementation

We recognize that projects vary at Truss, and it would be impossible to verbatim follow these decisions. Some projects will use tools based on client needs, or some may work in completely different domains. When Truss is responsible for the technology decisions and applications are similar to a past pattern, projects should seek to utilize known resources first. Practice ADR repositories should be consulted prior to writing a new ADR.

In the end, it is the Eng Lead's responsibility to decide when a decision is applicable. If a relevant ADR is ignored, the Eng Lead (or a delegate) should write justification within their project's new ADR. If the decision is succesful/overturns an existing one, a new ADR should be proposed to the practice using the above process.