diff --git a/docs/developer.md b/docs/developer.md
index a18ac3323..17745cca1 100644
--- a/docs/developer.md
+++ b/docs/developer.md
@@ -315,6 +315,23 @@ Then you can for example check the Patroni logs:
 kubectl logs acid-minimal-cluster-0
 ```
 
+## End-to-end tests
+
+The operator provides e2e (end-to-end) tests to ensure various infra parts work smoothly together.
+Such tests employ [kind](https://kind.sigs.k8s.io/) to start a local k8s cluster.
+We intend to execute e2e tests during builds, but you can invoke them locally with `make e2e` from the project's top directory. 
+
+### Smoke tests
+
+The first provided collection of [smoke tests](../e2e/tests/test_smoke.py) covers the most basic operator capabilities. These tests utilize examples from `/manifests` (ConfigMap is used for the operator configuration) to avoid maintaining yet another set of configuration files. The `kind-smoke-test-postgres-operator` cluster is deleted if tests complete successfully.
+
+### Contributing tests suites
+
+1. Consider using a separate `kind` cluster per a logically separate collection of tests. This approach enables simple clean up after test success by deleting the relevant cluster.
+2. Make tests time out; for now we use the [timeout-decorator](https://github.com/pnpnpn/timeout-decorator) for that purpose.
+3. Please briefly describe the use case for the new test collection here and in the comments.
+
+
 ## Introduce additional configuration parameters
 
 In the case you want to add functionality to the operator that shall be