Contract Testing for Microservices

February 22, 2026

Contract-Test-Design, Pact-Implementation, Schema-Compatibility-Testing, Ci-Test-Integration

Contract-Testing, Pact, Consumer-Driven-Contracts, Schema-Testing, Avro, Protobuf, Api-Testing, Ci-Testing

Pact, Pact-Broker, Schema-Registry, Protobuf, Avro

Contract Testing for Microservices#

Integration tests verify that services work together, but they require all services to be running. In a system with 20 services, running full integration tests is slow, brittle, and blocks deployments. Contract testing solves this by verifying service interactions independently – each service tests against a contract instead of against a live instance of every dependency.

The Problem with Integration and E2E Tests#

A traditional integration test for “order service calls payment service” requires both services running, along with their databases, message brokers, and any other dependencies. Problems:

Testing Strategy Selection: Unit, Integration, E2E, and Beyond

February 22, 2026

Developer-Workflows

Intermediate, Advanced

Testing-Strategy-Design, Test-Type-Selection, Test-Suite-Architecture, Quality-Assurance-Planning

Testing, Unit-Testing, Integration-Testing, E2e-Testing, Contract-Testing, Property-Based-Testing, Snapshot-Testing, Tdd, Testing-Pyramid

Jest, Pytest, Go-Test, Cypress, Playwright, Pact, Vitest, Testcontainers

Testing Strategy Selection#

Choosing the right mix of tests determines whether your test suite catches real bugs or just consumes CI minutes. There is no single correct answer – the right strategy depends on your system architecture, team size, deployment cadence, and the cost of production failures.

The Testing Pyramid#

The classic testing pyramid, introduced by Mike Cohn, prescribes many unit tests at the base, fewer integration tests in the middle, and a small number of end-to-end tests at the top.