Migrating to microservices is one conversation. Designing a microservices architecture that does not collapse into a distributed monolith is another. This is about the principles that separate the two,independent of whether you are migrating or building greenfield.

Service boundaries follow business capabilities, not technical layers

The most common mistake is slicing services by technical layer,a "models service," a "controllers service." Boundaries should follow business capabilities and bounded contexts: an Orders service, a Shipping service, a Billing service, each owning a complete vertical slice of its domain.

Each service owns its data,no exceptions

A shared database between services is the single fastest way to end up with a distributed monolith: any schema change now requires coordinating deploys across teams, and the "independent services" are independent in name only.

// Anti-pattern: Shipping service queries the Orders database directly
$order = DB::connection('orders_db')->table('orders')->find($orderId);

// Pattern: Shipping service asks the Orders service through its API
$order = Http::get(config('services.orders.url') . "/orders/{$orderId}")->json();

Communication patterns: choose deliberately

• ✓Synchronous REST or gRPC for requests that need an immediate answer,authentication, payment authorization.
• ✓Asynchronous messaging (events, queues) for anything that can happen eventually,notifications, analytics, audit logs.
• ✓Avoid chatty synchronous chains where service A waits on B which waits on C,latency and failure modes compound with every hop.

Design for failure: nothing here is optional

• ✓Timeouts and circuit breakers on every network call,a slow dependency should not cascade into a full outage.
• ✓Retries with exponential backoff, paired with idempotency keys so retried writes do not duplicate data.
• ✓Graceful degradation: define what your service does when a dependency is down, instead of discovering it in production.

Observability is not optional either

A single user request can touch six services. Without distributed tracing (OpenTelemetry), correlation IDs propagated across every call, and centralized logging, debugging that request is guesswork dressed up as an incident report.

Microservices trade simplicity for scalability and team autonomy. That trade is worth making once your team or domain has outgrown a single deployable unit,not by default, and not because the term is fashionable.