PHP application architecture designed to evolve
Useful architecture reduces the cost of changing rules, integrating systems and operating the product. Its quality is tested through decisions and delivery, not layer count.
- Model capabilities and responsibilities.
- Make contracts and data ownership explicit.
- Choose distribution for team and operations.
- Record decisions and test them through real change.
Use the guide to prepare a real decision
The goal is not to complete a reading, but to improve the quality of a technical and business conversation.
Begin by defining which situation needs to change, who depends on the outcome and which constraints cannot be ignored. Gather enough examples, metrics, incidents, architecture and previous decisions to separate facts from perceptions. The guide helps organise that evidence; it does not replace system-specific knowledge.
Then compare options by impact, risk, reversibility and team capability. A useful conclusion identifies the next proportionate step, the evidence it should produce and the conditions that would require the plan to be reviewed. This prevents a general recommendation from becoming an investment that is hard to correct.
- PrepareContext, evidence, constraints and owners.
- ChallengeOptions, assumptions, risks and change costs.
- DecideNext step, boundary and success criterion.
- ReviewOutcomes and conditions changing the decision.
1. Start with the domain
Describe actors, journeys, rules, exceptions and language. Technical boundaries remain more stable when they reflect business responsibility rather than folders or tables.
- Business capabilities.
- Rules and invariants.
- Actors and permissions.
- Important events and decisions.
2. Design boundaries
Every component needs a reason to change, interface and owner. A useful boundary reduces shared knowledge; an artificial one adds conversion and coordination without real independence.
- What it knows and hides.
- Input, output and errors.
- Allowed dependencies.
- Contract tests.
3. Treat data as a decision
Define source of truth, consistency, retention and migration. Sharing tables feels fast but creates invisible contracts and makes evolution, security and audit harder.
- Ownership and lifecycle.
- Immediate or eventual consistency.
- History and traceability.
- Privacy and access.
4. Choose monolith or distribution
A modular monolith is often effective when team and operations are shared. Independent services fit when boundaries, delivery, scale or accountability are genuinely different.
- Team size and autonomy.
- Independent release needs.
- Load and availability by capability.
- Network, observability and consistency cost.
5. Design for operations
Architecture includes configuration, release, recovery, observation and support. A component that cannot be diagnosed or restored is not complete.
- Environment configuration.
- Logs, metrics and traces.
- Release and rollback.
- Backup and recovery.
6. Keep decisions alive
Record context, alternatives and consequences through ADRs or another simple format. Review a decision when constraints change; do not turn the document into disconnected policy.
- Decision and date.
- Context and forces.
- Rejected alternatives.
- Consequences and review signal.
Content connected to this decision
Continue with diagnosis, execution or related experience.
Apply the guide to your application
We review the situation, evidence and options without tying the assessment to implementation.