diff --git a/README.md b/README.md
index d24cc19..46192b0 100644
--- a/README.md
+++ b/README.md
@@ -138,9 +138,11 @@ docker compose up -d
 - `openremit-mysql` (3306, binlog ROW + GTID 활성)
 - `openremit-redis` (6379)
 - `openremit-kafka` (9092 host / 29092 internal, KRaft single-node)
-- `openremit-mock-fx` (9999), `openremit-mock-payout` (9998) — WireMock
+- `openremit-mock-fx` (9999), `openremit-mock-payout` (9998), `openremit-mock-webhook` (9997) — WireMock
 - `openremit-debezium` (8083) — Connect standalone
 - `openremit-debezium-register` — outbox 커넥터 자동 등록 (1회성, retry 6회)
+- `openremit-prometheus` (9090) — `host.docker.internal`로 호스트 JVM의 4개 모듈 scrape
+- `openremit-grafana` (3000) — anonymous Viewer 허용, datasource(`prometheus`) + 대시보드(`openremit`) provisioning
 
 검증:
 ```bash
@@ -158,3 +160,37 @@ docker exec -it openremit-kafka /opt/kafka/bin/kafka-console-consumer.sh \
 ```
 
 볼륨 초기화가 필요하면 `docker compose down -v` 후 재기동 (mysql-init 스크립트가 다시 실행되어 Debezium 사용자가 생성됨).
+
+## 관측성 — 메트릭 / 로그 (Day 12)
+
+### 메트릭
+
+각 Spring Boot 모듈이 `/actuator/prometheus`를 노출하고, `docker-compose`의 Prometheus가 `host.docker.internal:808x`로 scrape 합니다.
+
+```bash
+curl -s http://localhost:8080/actuator/prometheus | head    # remittance-api
+curl -s http://localhost:9090/api/v1/targets | jq '.data.activeTargets[].health'
+```
+
+| 모듈 | actuator 포트 | prometheus 라벨 |
+|---|---|---|
+| `remittance-api` | 8080 | `service="remittance-api"` |
+| `payout-worker` | 8081 | `service="payout-worker"` |
+| `webhook-dispatcher` | 8082 | `service="webhook-dispatcher"` |
+| `reconciler` | 8084 | `service="reconciler"` |
+
+Grafana 접속: `http://localhost:3000` (anonymous Viewer). 좌측 메뉴 → Dashboards → **OpenRemit / OpenRemit — Service Overview** 자동 로드. 대시보드 UID는 `openremit`이며 [`docker/grafana/dashboards/openremit.json`](docker/grafana/dashboards/openremit.json)에서 관리합니다.
+
+### 로깅
+
+`logback-spring.xml`은 `common` 모듈에 단일 정의되며 profile에 따라 분기합니다.
+
+- **`local`** (개발): 사람이 읽기 좋은 콘솔 텍스트
+- **그 외 default/docker/prod**: 한 줄 JSON (`logstash-logback-encoder` 8.0)
+
+```bash
+SPRING_PROFILES_ACTIVE=local ./gradlew :remittance-api:bootRun   # 텍스트
+./gradlew :remittance-api:bootRun                                # JSON (default)
+```
+
+JSON 한 줄에는 `@timestamp`, `level`, `logger_name`, `thread_name`, `message`, `appName`(=spring.application.name), `app`(customField, 동일 값) 필드가 부착되어 Loki/ELK/Datadog 같은 수집기에서 즉시 라벨링 가능합니다.
diff --git a/common/src/main/resources/logback-spring.xml b/common/src/main/resources/logback-spring.xml
new file mode 100644
index 0000000..1643fb7
--- /dev/null
+++ b/common/src/main/resources/logback-spring.xml
@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <include resource="org/springframework/boot/logging/logback/defaults.xml"/>
+
+    <springProperty scope="context" name="appName" source="spring.application.name" defaultValue="openremit"/>
+
+    <!-- local profile: 사람이 읽기 쉬운 콘솔 텍스트 -->
+    <springProfile name="local">
+        <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
+            <encoder>
+                <pattern>%d{HH:mm:ss.SSS} %-5level [%thread] %logger{36} - %msg%n</pattern>
+            </encoder>
+        </appender>
+    </springProfile>
+
+    <!-- 그 외 profile (default/docker/prod): Logstash JSON 한 줄 -->
+    <springProfile name="!local">
+        <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
+            <encoder class="net.logstash.logback.encoder.LogstashEncoder">
+                <includeMdcKeyName>traceId</includeMdcKeyName>
+                <includeMdcKeyName>spanId</includeMdcKeyName>
+                <customFields>{"app":"${appName}"}</customFields>
+            </encoder>
+        </appender>
+    </springProfile>
+
+    <root level="INFO">
+        <appender-ref ref="CONSOLE"/>
+    </root>
+</configuration>
diff --git a/docker-compose.yml b/docker-compose.yml
index 4e77a67..977202e 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -169,6 +169,47 @@ services:
         exit 1
     restart: "no"
 
+  prometheus:
+    image: prom/prometheus:v2.55.0
+    container_name: openremit-prometheus
+    ports:
+      - "9090:9090"
+    volumes:
+      - ./docker/prometheus.yml:/etc/prometheus/prometheus.yml:ro
+      - prometheus-data:/prometheus
+    extra_hosts:
+      - "host.docker.internal:host-gateway"
+    healthcheck:
+      test: ["CMD-SHELL", "wget -q -O- http://localhost:9090/-/ready >/dev/null || exit 1"]
+      interval: 10s
+      timeout: 3s
+      retries: 10
+
+  grafana:
+    image: grafana/grafana:11.3.0
+    container_name: openremit-grafana
+    depends_on:
+      prometheus:
+        condition: service_healthy
+    ports:
+      - "3000:3000"
+    environment:
+      GF_SECURITY_ADMIN_USER: admin
+      GF_SECURITY_ADMIN_PASSWORD: admin
+      GF_AUTH_ANONYMOUS_ENABLED: "true"
+      GF_AUTH_ANONYMOUS_ORG_ROLE: Viewer
+    volumes:
+      - ./docker/grafana/provisioning:/etc/grafana/provisioning:ro
+      - ./docker/grafana/dashboards:/var/lib/grafana/dashboards:ro
+      - grafana-data:/var/lib/grafana
+    healthcheck:
+      test: ["CMD-SHELL", "wget -q -O- http://localhost:3000/api/health >/dev/null || exit 1"]
+      interval: 10s
+      timeout: 3s
+      retries: 10
+
 volumes:
   mysql-data:
   redis-data:
+  prometheus-data:
+  grafana-data:
diff --git a/docker/grafana/dashboards/openremit.json b/docker/grafana/dashboards/openremit.json
new file mode 100644
index 0000000..bd69c47
--- /dev/null
+++ b/docker/grafana/dashboards/openremit.json
@@ -0,0 +1,112 @@
+{
+  "uid": "openremit",
+  "title": "OpenRemit — Service Overview",
+  "tags": ["openremit"],
+  "schemaVersion": 39,
+  "timezone": "browser",
+  "refresh": "10s",
+  "time": { "from": "now-30m", "to": "now" },
+  "templating": {
+    "list": [
+      {
+        "name": "service",
+        "type": "query",
+        "datasource": { "type": "prometheus", "uid": "prometheus" },
+        "query": "label_values(http_server_requests_seconds_count, service)",
+        "refresh": 2,
+        "includeAll": true,
+        "multi": true,
+        "current": { "text": "All", "value": "$__all" }
+      }
+    ]
+  },
+  "panels": [
+    {
+      "id": 1,
+      "type": "timeseries",
+      "title": "HTTP p95 latency by URI",
+      "gridPos": { "x": 0, "y": 0, "w": 12, "h": 8 },
+      "fieldConfig": { "defaults": { "unit": "s" } },
+      "targets": [
+        {
+          "expr": "histogram_quantile(0.95, sum by (le, uri) (rate(http_server_requests_seconds_bucket{service=~\"$service\"}[1m])))",
+          "legendFormat": "{{uri}}"
+        }
+      ]
+    },
+    {
+      "id": 2,
+      "type": "timeseries",
+      "title": "Remittance throughput (POST /api/v1/remittances req/s)",
+      "gridPos": { "x": 12, "y": 0, "w": 12, "h": 8 },
+      "fieldConfig": { "defaults": { "unit": "reqps" } },
+      "targets": [
+        {
+          "expr": "sum by (status) (rate(http_server_requests_seconds_count{service=\"remittance-api\", uri=\"/api/v1/remittances\", method=\"POST\"}[1m]))",
+          "legendFormat": "status={{status}}"
+        }
+      ]
+    },
+    {
+      "id": 3,
+      "type": "stat",
+      "title": "Circuit Breaker state (fx-rate)",
+      "gridPos": { "x": 0, "y": 8, "w": 8, "h": 6 },
+      "fieldConfig": {
+        "defaults": {
+          "mappings": [
+            { "type": "value", "options": { "0": { "text": "INACTIVE", "color": "text" } } },
+            { "type": "value", "options": { "1": { "text": "ACTIVE", "color": "green" } } }
+          ],
+          "thresholds": { "mode": "absolute", "steps": [{ "color": "green", "value": null }] }
+        }
+      },
+      "options": { "reduceOptions": { "calcs": ["lastNotNull"], "fields": "", "values": false } },
+      "targets": [
+        {
+          "expr": "resilience4j_circuitbreaker_state{name=\"fx-rate\"}",
+          "legendFormat": "{{state}}"
+        }
+      ]
+    },
+    {
+      "id": 4,
+      "type": "timeseries",
+      "title": "CB calls by kind (fx-rate)",
+      "gridPos": { "x": 8, "y": 8, "w": 16, "h": 6 },
+      "fieldConfig": { "defaults": { "unit": "ops" } },
+      "targets": [
+        {
+          "expr": "sum by (kind) (rate(resilience4j_circuitbreaker_calls_seconds_count{name=\"fx-rate\"}[1m]))",
+          "legendFormat": "{{kind}}"
+        }
+      ]
+    },
+    {
+      "id": 5,
+      "type": "timeseries",
+      "title": "JVM heap used",
+      "gridPos": { "x": 0, "y": 14, "w": 12, "h": 7 },
+      "fieldConfig": { "defaults": { "unit": "bytes" } },
+      "targets": [
+        {
+          "expr": "sum by (service) (jvm_memory_used_bytes{area=\"heap\", service=~\"$service\"})",
+          "legendFormat": "{{service}}"
+        }
+      ]
+    },
+    {
+      "id": 6,
+      "type": "timeseries",
+      "title": "HTTP request rate by service",
+      "gridPos": { "x": 12, "y": 14, "w": 12, "h": 7 },
+      "fieldConfig": { "defaults": { "unit": "reqps" } },
+      "targets": [
+        {
+          "expr": "sum by (service) (rate(http_server_requests_seconds_count{service=~\"$service\"}[1m]))",
+          "legendFormat": "{{service}}"
+        }
+      ]
+    }
+  ]
+}
diff --git a/docker/grafana/provisioning/dashboards/provider.yml b/docker/grafana/provisioning/dashboards/provider.yml
new file mode 100644
index 0000000..ee81986
--- /dev/null
+++ b/docker/grafana/provisioning/dashboards/provider.yml
@@ -0,0 +1,12 @@
+apiVersion: 1
+providers:
+  - name: openremit
+    orgId: 1
+    folder: OpenRemit
+    type: file
+    disableDeletion: false
+    updateIntervalSeconds: 30
+    allowUiUpdates: true
+    options:
+      path: /var/lib/grafana/dashboards
+      foldersFromFilesStructure: false
diff --git a/docker/grafana/provisioning/datasources/prometheus.yml b/docker/grafana/provisioning/datasources/prometheus.yml
new file mode 100644
index 0000000..433ef5c
--- /dev/null
+++ b/docker/grafana/provisioning/datasources/prometheus.yml
@@ -0,0 +1,9 @@
+apiVersion: 1
+datasources:
+  - name: Prometheus
+    uid: prometheus
+    type: prometheus
+    access: proxy
+    url: http://prometheus:9090
+    isDefault: true
+    editable: false
diff --git a/docker/prometheus.yml b/docker/prometheus.yml
new file mode 100644
index 0000000..4219b3d
--- /dev/null
+++ b/docker/prometheus.yml
@@ -0,0 +1,16 @@
+global:
+  scrape_interval: 15s
+  evaluation_interval: 15s
+
+scrape_configs:
+  - job_name: openremit
+    metrics_path: /actuator/prometheus
+    static_configs:
+      - targets: ["host.docker.internal:8080"]
+        labels: { service: remittance-api }
+      - targets: ["host.docker.internal:8081"]
+        labels: { service: payout-worker }
+      - targets: ["host.docker.internal:8082"]
+        labels: { service: webhook-dispatcher }
+      - targets: ["host.docker.internal:8084"]
+        labels: { service: reconciler }
diff --git a/payout-worker/build.gradle.kts b/payout-worker/build.gradle.kts
index cdd5e67..ddbf190 100644
--- a/payout-worker/build.gradle.kts
+++ b/payout-worker/build.gradle.kts
@@ -13,6 +13,8 @@ dependencies {
     implementation(project(":common"))
 
     implementation("org.springframework.boot:spring-boot-starter-actuator")
+    implementation("io.micrometer:micrometer-registry-prometheus")
+    implementation("net.logstash.logback:logstash-logback-encoder:8.0")
     implementation("org.springframework.boot:spring-boot-starter-data-jpa")
     implementation("org.springframework.boot:spring-boot-starter-flyway")
     implementation("org.springframework.boot:spring-boot-starter-webmvc")
diff --git a/payout-worker/src/main/resources/application.yaml b/payout-worker/src/main/resources/application.yaml
index a41421b..614fa4f 100644
--- a/payout-worker/src/main/resources/application.yaml
+++ b/payout-worker/src/main/resources/application.yaml
@@ -47,7 +47,14 @@ management:
   endpoints:
     web:
       exposure:
-        include: health,info,metrics
+        include: health,info,metrics,prometheus
   endpoint:
     health:
       show-details: when-authorized
+  metrics:
+    tags:
+      application: ${spring.application.name}
+  prometheus:
+    metrics:
+      export:
+        enabled: true
diff --git a/reconciler/build.gradle.kts b/reconciler/build.gradle.kts
index 5e0911b..ed5c010 100644
--- a/reconciler/build.gradle.kts
+++ b/reconciler/build.gradle.kts
@@ -13,6 +13,10 @@ dependencies {
     implementation(project(":common"))
 
     implementation("org.springframework.boot:spring-boot-starter-actuator")
+    implementation("io.micrometer:micrometer-registry-prometheus")
+    implementation("net.logstash.logback:logstash-logback-encoder:8.0")
+    // batch 모듈이지만 actuator/prometheus HTTP scrape를 위해 webmvc 임베디드 (Day 12)
+    implementation("org.springframework.boot:spring-boot-starter-webmvc")
     implementation("org.springframework.boot:spring-boot-starter-data-jpa")
     implementation("org.springframework.boot:spring-boot-starter-flyway")
     implementation("org.springframework.boot:spring-boot-starter-batch")
diff --git a/reconciler/src/main/resources/application.yaml b/reconciler/src/main/resources/application.yaml
index 32595eb..a29a4a2 100644
--- a/reconciler/src/main/resources/application.yaml
+++ b/reconciler/src/main/resources/application.yaml
@@ -41,10 +41,17 @@ management:
   endpoints:
     web:
       exposure:
-        include: health,info,metrics
+        include: health,info,metrics,prometheus
   endpoint:
     health:
       show-details: when-authorized
+  metrics:
+    tags:
+      application: ${spring.application.name}
+  prometheus:
+    metrics:
+      export:
+        enabled: true
 
 openremit:
   reconcile:
diff --git a/remittance-api/build.gradle.kts b/remittance-api/build.gradle.kts
index c62eeb1..184c4c1 100644
--- a/remittance-api/build.gradle.kts
+++ b/remittance-api/build.gradle.kts
@@ -11,6 +11,8 @@ allOpen {
 
 dependencies {
     implementation("org.springframework.boot:spring-boot-starter-actuator")
+    implementation("io.micrometer:micrometer-registry-prometheus")
+    implementation("net.logstash.logback:logstash-logback-encoder:8.0")
     implementation("org.springframework.boot:spring-boot-starter-data-jpa")
     implementation("org.springframework.boot:spring-boot-starter-flyway")
     implementation("org.springframework.boot:spring-boot-starter-webmvc")
diff --git a/remittance-api/src/main/resources/application.yaml b/remittance-api/src/main/resources/application.yaml
index 20045f7..13de563 100644
--- a/remittance-api/src/main/resources/application.yaml
+++ b/remittance-api/src/main/resources/application.yaml
@@ -78,7 +78,14 @@ management:
   endpoints:
     web:
       exposure:
-        include: health,info,metrics
+        include: health,info,metrics,prometheus
   endpoint:
     health:
       show-details: when-authorized
+  metrics:
+    tags:
+      application: ${spring.application.name}
+  prometheus:
+    metrics:
+      export:
+        enabled: true
diff --git a/webhook-dispatcher/build.gradle.kts b/webhook-dispatcher/build.gradle.kts
index cdd5e67..ddbf190 100644
--- a/webhook-dispatcher/build.gradle.kts
+++ b/webhook-dispatcher/build.gradle.kts
@@ -13,6 +13,8 @@ dependencies {
     implementation(project(":common"))
 
     implementation("org.springframework.boot:spring-boot-starter-actuator")
+    implementation("io.micrometer:micrometer-registry-prometheus")
+    implementation("net.logstash.logback:logstash-logback-encoder:8.0")
     implementation("org.springframework.boot:spring-boot-starter-data-jpa")
     implementation("org.springframework.boot:spring-boot-starter-flyway")
     implementation("org.springframework.boot:spring-boot-starter-webmvc")
diff --git a/webhook-dispatcher/src/main/resources/application.yaml b/webhook-dispatcher/src/main/resources/application.yaml
index 194d746..3fb54a4 100644
--- a/webhook-dispatcher/src/main/resources/application.yaml
+++ b/webhook-dispatcher/src/main/resources/application.yaml
@@ -52,7 +52,14 @@ management:
   endpoints:
     web:
       exposure:
-        include: health,info,metrics
+        include: health,info,metrics,prometheus
   endpoint:
     health:
       show-details: when-authorized
+  metrics:
+    tags:
+      application: ${spring.application.name}
+  prometheus:
+    metrics:
+      export:
+        enabled: true