Owner: Vadim Rudakov, lefthand67@gmail
Version: 0.1.0
Birth: 2025-12-15
Last Modified: 2025-12-15
Appendix A: Detailed ArchTag Commit Examples¶
These examples illustrate the correct structure for commits that require Tier 3 architectural justification, using the ArchTag:TAG-NAME format.
1. ArchTag: DEPRECATION-PLANNED¶
Goal: Remove a function slated for sunsetting.
feat: remove legacy user analytics module
ArchTag:DEPRECATION-PLANNED
This module has been replaced by the new Kafka-based logging system (see JIRA-255).
All calls to `legacy_analytics_log()` have been removed from the frontend service.
BREAKING CHANGE: The `legacy_analytics_log()` function and its HTTP endpoint /api/v1/log are no longer available.2. ArchTag: TECHDEBT-PAYMENT¶
Goal: Restructure code to improve maintainability and adherence to modern Python standards.
refactor: standardize all model config loading via Pydantic
ArchTag:TECHDEBT-PAYMENT
Replaced outdated dict-based config parsing with Pydantic schemas across 12 files.
This significantly reduces validation error handling boilerplate and improves type safety.3. ArchTag: REFACTOR-MIGRATION¶
Goal: Implement a fundamental shift in how the system handles a core component.
refactor: migrate database connection pool to SQLAlchemy 2.0 async
ArchTag:REFACTOR-MIGRATION
Upgraded the core data layer to use the new asyncio ORM style.
This is a breaking change and requires updating all repository methods to use `await`.4. ArchTag: PERF-OPTIMIZATION¶
Goal: Optimize a slow loop, requiring proof of performance gain.
perf: optimize feature extraction by replacing list with numpy array
ArchTag:PERF-OPTIMIZATION
Profiling showed the bottleneck was array conversion in the main loop.
Benchmark results show a 22% reduction in latency for large inputs (1000+ features).Appendix B: The Big Tech Philosophy: Atomic Submission¶
The large-scale tech companies (Meta, Google, etc.) have workflows built around a concept called the Small Change List (CL), which mandates that the unit of submission is one, single, atomic change. This philosophy heavily favors one of the merge strategies, but not in the standard way.
The guiding principle is one logical change one commit to the mainline branch. This ensures maximum:
Revertability: If the change breaks production, the entire feature can be removed instantly with one
git revert.Reviewability: Reviewers only assess a single, focused change that does one thing.
Traceability:
git blameand changelogs point directly to the full feature/fix, not an intermediate development step.
How Each Company Achieves This¶
Your understanding that they heavily use rebase is correct, but the context is key.
1. Google (Squash and Merge)¶
Workflow: Google uses an internal version control system (Piper, conceptually similar to Perforce, but with front-ends that make it feel like Git). Their primary mechanism for submission is the CL (Changelist), which is conceptually identical to a single, atomic commit.
Git Equivalent: The closest public Git equivalent to their merge strategy is Squash and Merge. All intermediate commits created during development on a feature branch are flattened into one single, clean, atomic commit for the mainline repository.
The Role of Rebase: Developers do use
git rebaselocally to clean up their history (squash “WIP” or “fix typo” commits) before submitting the single CL for review.
2. Meta (Rebase, but with Stacked Diffs)¶
Workflow: Meta primarily uses a version control system called Mercurial (though they have highly customized their tooling around it, notably Sapling). They are the pioneers of Stacked Diffs or Stacked Changes.
Stacked Diffs: A large feature is split into a stack of many small, dependent, atomic changes (e.g., Change A depends on B, B depends on C). Each change is reviewed and submitted independently.
Git Equivalent: When these individual atomic changes are submitted, they are often integrated in a way that is equivalent to a Rebase and Merge or a Fast-Forward Merge, where no merge commit is created, and the history remains perfectly linear. This preserves the full, clean, atomic commit history of the stack.
Key Difference: The history Meta preserves is a series of clean, atomic, reviewed commits. They do not preserve messy development history.