diff --git a/backend/Cargo.lock b/backend/Cargo.lock
index 11c743a643..a476bded1f 100644
--- a/backend/Cargo.lock
+++ b/backend/Cargo.lock
@@ -15828,6 +15828,8 @@ dependencies = [
  "git-version",
  "lazy_static",
  "once_cell",
+ "opentelemetry 0.30.0",
+ "opentelemetry_sdk 0.30.0",
  "prometheus",
  "rand 0.9.0",
  "rdkafka",
diff --git a/backend/Cargo.toml b/backend/Cargo.toml
index b8e4d3d593..31d5665cd7 100644
--- a/backend/Cargo.toml
+++ b/backend/Cargo.toml
@@ -260,6 +260,8 @@ windmill-dep-map.workspace = true
 windmill-test-utils.workspace = true
 windmill-worker-volumes.workspace = true
 windmill-types.workspace = true
+opentelemetry = { workspace = true }
+opentelemetry_sdk = { workspace = true }
 windmill-trigger.workspace = true
 windmill-trigger-websocket.workspace = true
 windmill-trigger-postgres.workspace = true
@@ -568,7 +570,7 @@ async-stream = "^0"
 
 opentelemetry = "0.30.0"
 tracing-opentelemetry = "0.31.0"
-opentelemetry_sdk = { version = "0.30.0", features = ["rt-tokio"] }
+opentelemetry_sdk = { version = "0.30.0", features = ["rt-tokio", "testing"] }
 opentelemetry-otlp = { version = "0.30.0", features = ["grpc-tonic", "tls"] }
 opentelemetry-appender-tracing = "0.30.0"
 opentelemetry-semantic-conventions = { version = "0.30.0", features = ["semconv_experimental"] }
diff --git a/backend/tests/otel.rs b/backend/tests/otel.rs
new file mode 100644
index 0000000000..dd56cbf425
--- /dev/null
+++ b/backend/tests/otel.rs
@@ -0,0 +1,504 @@
+//! E2E tests for OpenTelemetry integration.
+//!
+//! Verify that metrics are recorded with correct names/values/attributes and
+//! spans are created with correct trace IDs, attributes, and status codes.
+//!
+//! Run with: cargo test --features enterprise,private,otel --test otel -- --test-threads=1
+
+#![cfg(all(feature = "otel", feature = "enterprise"))]
+
+use std::sync::{atomic::Ordering, Arc};
+
+use opentelemetry::global;
+use opentelemetry::trace::TracerProvider as _;
+use opentelemetry_sdk::{
+    metrics::{InMemoryMetricExporter, PeriodicReader, SdkMeterProvider},
+    trace::{InMemorySpanExporter, SdkTracerProvider, SimpleSpanProcessor},
+};
+use windmill_common::otel_ee::*;
+use windmill_common::{OTEL_METRICS_ENABLED, OTEL_TRACING_ENABLED};
+
+// ── Global test infrastructure ──────────────────────────────────────────
+
+struct OtelTestState {
+    metric_exporter: InMemoryMetricExporter,
+    span_exporter: InMemorySpanExporter,
+    meter_provider: SdkMeterProvider,
+}
+
+static STATE: tokio::sync::OnceCell<Arc<OtelTestState>> = tokio::sync::OnceCell::const_new();
+
+async fn ensure_setup() -> Arc<OtelTestState> {
+    STATE
+        .get_or_init(|| async {
+            // Metrics: InMemoryMetricExporter + PeriodicReader (needs async tokio context)
+            let metric_exporter = InMemoryMetricExporter::default();
+            let reader = PeriodicReader::builder(metric_exporter.clone()).build();
+            let meter_provider = SdkMeterProvider::builder().with_reader(reader).build();
+            global::set_meter_provider(meter_provider.clone());
+            OTEL_METRICS_ENABLED.store(true, Ordering::SeqCst);
+
+            // Tracing: InMemorySpanExporter + SimpleSpanProcessor
+            let span_exporter = InMemorySpanExporter::default();
+            let tracer_provider = SdkTracerProvider::builder()
+                .with_span_processor(SimpleSpanProcessor::new(span_exporter.clone()))
+                .build();
+            let tracer = tracer_provider.tracer("windmill");
+            *TRACER.write().unwrap() = Some(tracer);
+            OTEL_TRACING_ENABLED.store(true, Ordering::SeqCst);
+
+            Arc::new(OtelTestState { metric_exporter, span_exporter, meter_provider })
+        })
+        .await
+        .clone()
+}
+
+// ── Metric helper: flush + collect ──────────────────────────────────────
+
+fn flush_and_get_metrics(
+    state: &OtelTestState,
+) -> Vec<opentelemetry_sdk::metrics::data::ResourceMetrics> {
+    state.meter_provider.force_flush().expect("flush failed");
+    state
+        .metric_exporter
+        .get_finished_metrics()
+        .expect("get_finished_metrics failed")
+}
+
+fn find_metric<'a>(
+    all: &'a [opentelemetry_sdk::metrics::data::ResourceMetrics],
+    name: &str,
+) -> Option<&'a opentelemetry_sdk::metrics::data::Metric> {
+    all.iter()
+        .flat_map(|rm| rm.scope_metrics())
+        .flat_map(|sm| sm.metrics())
+        .find(|m| m.name() == name)
+}
+
+fn metric_names(all: &[opentelemetry_sdk::metrics::data::ResourceMetrics]) -> Vec<String> {
+    all.iter()
+        .flat_map(|rm| rm.scope_metrics())
+        .flat_map(|sm| sm.metrics())
+        .map(|m| m.name().to_string())
+        .collect()
+}
+
+// ── Counter value helpers ───────────────────────────────────────────────
+
+fn sum_u64_value(metric: &opentelemetry_sdk::metrics::data::Metric) -> Option<u64> {
+    use opentelemetry_sdk::metrics::data::{AggregatedMetrics, MetricData};
+    match metric.data() {
+        AggregatedMetrics::U64(MetricData::Sum(sum)) => {
+            Some(sum.data_points().map(|dp| dp.value()).sum())
+        }
+        _ => None,
+    }
+}
+
+fn gauge_i64_values(
+    metric: &opentelemetry_sdk::metrics::data::Metric,
+) -> Vec<(Vec<opentelemetry::KeyValue>, i64)> {
+    use opentelemetry_sdk::metrics::data::{AggregatedMetrics, MetricData};
+    match metric.data() {
+        AggregatedMetrics::I64(MetricData::Gauge(gauge)) => gauge
+            .data_points()
+            .map(|dp| (dp.attributes().cloned().collect(), dp.value()))
+            .collect(),
+        _ => panic!("expected I64 Gauge metric"),
+    }
+}
+
+fn gauge_f64_value(metric: &opentelemetry_sdk::metrics::data::Metric) -> Option<f64> {
+    use opentelemetry_sdk::metrics::data::{AggregatedMetrics, MetricData};
+    match metric.data() {
+        AggregatedMetrics::F64(MetricData::Gauge(gauge)) => {
+            gauge.data_points().next().map(|dp| dp.value())
+        }
+        _ => None,
+    }
+}
+
+fn histogram_f64_count(metric: &opentelemetry_sdk::metrics::data::Metric) -> Option<u64> {
+    use opentelemetry_sdk::metrics::data::{AggregatedMetrics, MetricData};
+    match metric.data() {
+        AggregatedMetrics::F64(MetricData::Histogram(hist)) => {
+            Some(hist.data_points().map(|dp| dp.count()).sum())
+        }
+        _ => None,
+    }
+}
+
+fn histogram_f64_sum(metric: &opentelemetry_sdk::metrics::data::Metric) -> Option<f64> {
+    use opentelemetry_sdk::metrics::data::{AggregatedMetrics, MetricData};
+    match metric.data() {
+        AggregatedMetrics::F64(MetricData::Histogram(hist)) => {
+            Some(hist.data_points().map(|dp| dp.sum()).sum())
+        }
+        _ => None,
+    }
+}
+
+// ═══════════════════════════════════════════════════════════════════════
+// METRICS E2E TEST
+//
+// All metric assertions live in one test function because the PeriodicReader's
+// background task is tied to the tokio runtime that created it. Separate
+// #[tokio::test] functions each get their own runtime, and the reader becomes
+// disconnected after the first test's runtime is dropped.
+// ═══════════════════════════════════════════════════════════════════════
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn test_all_metrics_e2e() {
+    let state = ensure_setup().await;
+
+    // ── Counters ────────────────────────────────────────────────────
+
+    otel_incr_queue_push_count();
+    otel_incr_queue_push_count();
+    otel_incr_queue_push_count();
+    otel_incr_queue_delete_count();
+    otel_incr_queue_pull_count();
+    otel_incr_zombie_restart_count(7);
+    otel_incr_zombie_delete_count(3);
+    otel_incr_worker_execution_count("bun");
+    otel_incr_worker_execution_count("bun");
+    otel_incr_worker_execution_failed("go");
+    otel_incr_worker_started();
+
+    // ── Gauges ──────────────────────────────────────────────────────
+
+    otel_set_queue_count("python3", 42);
+    otel_set_queue_running_count("deno", 5);
+    otel_set_worker_busy("worker-test-1", 1);
+    otel_set_db_pool(5, 10, 20);
+    otel_set_health_db_latency(2.5);
+    otel_set_worker_uptime("w-uptime", 3600.0);
+    otel_set_health_status_phase("healthy");
+    otel_set_health_db_unresponsive(true);
+
+    // ── Histograms ──────────────────────────────────────────────────
+
+    otel_record_worker_execution_duration("python3", 1.5);
+    otel_record_worker_execution_duration("python3", 2.5);
+    otel_record_worker_pull_duration("w1", true, 0.05);
+    otel_record_worker_pull_duration("w1", false, 0.01);
+
+    // ── Flush and collect ───────────────────────────────────────────
+
+    let metrics = flush_and_get_metrics(&state);
+    let names = metric_names(&metrics);
+
+    // ── Verify all 20 metric names are present ──────────────────────
+
+    let expected = [
+        "windmill.queue.push_count",
+        "windmill.queue.delete_count",
+        "windmill.queue.pull_count",
+        "windmill.queue.zombie_restart_count",
+        "windmill.queue.zombie_delete_count",
+        "windmill.queue.count",
+        "windmill.queue.running_count",
+        "windmill.worker.execution_count",
+        "windmill.worker.execution_duration",
+        "windmill.worker.busy",
+        "windmill.worker.pull_duration",
+        "windmill.worker.execution_failed",
+        "windmill.db.pool.active",
+        "windmill.db.pool.idle",
+        "windmill.db.pool.max",
+        "windmill.health.db_latency",
+        "windmill.worker.started",
+        "windmill.worker.uptime",
+        "windmill.health.status",
+        "windmill.health.db_unresponsive",
+    ];
+    for name in expected {
+        assert!(
+            names.iter().any(|n| n == name),
+            "metric '{}' not found in {:?}",
+            name,
+            names
+        );
+    }
+
+    // ── Counter values ──────────────────────────────────────────────
+
+    let m = find_metric(&metrics, "windmill.queue.push_count").unwrap();
+    assert!(sum_u64_value(m).unwrap() >= 3, "push_count should be >= 3");
+
+    let m = find_metric(&metrics, "windmill.queue.delete_count").unwrap();
+    assert!(sum_u64_value(m).unwrap() >= 1);
+
+    let m = find_metric(&metrics, "windmill.queue.pull_count").unwrap();
+    assert!(sum_u64_value(m).unwrap() >= 1);
+
+    let m = find_metric(&metrics, "windmill.queue.zombie_restart_count").unwrap();
+    assert!(sum_u64_value(m).unwrap() >= 7);
+
+    let m = find_metric(&metrics, "windmill.queue.zombie_delete_count").unwrap();
+    assert!(sum_u64_value(m).unwrap() >= 3);
+
+    let m = find_metric(&metrics, "windmill.worker.execution_count").unwrap();
+    assert!(sum_u64_value(m).unwrap() >= 2);
+
+    let m = find_metric(&metrics, "windmill.worker.execution_failed").unwrap();
+    assert!(sum_u64_value(m).unwrap() >= 1);
+
+    let m = find_metric(&metrics, "windmill.worker.started").unwrap();
+    assert!(sum_u64_value(m).unwrap() >= 1);
+
+    // ── Gauge values ────────────────────────────────────────────────
+
+    let m = find_metric(&metrics, "windmill.queue.count").unwrap();
+    let values = gauge_i64_values(m);
+    let dp = values
+        .iter()
+        .find(|(attrs, _)| {
+            attrs
+                .iter()
+                .any(|kv| kv.key.as_str() == "tag" && kv.value.as_str() == "python3")
+        })
+        .expect("queue.count data point with tag=python3 not found");
+    assert_eq!(dp.1, 42);
+
+    let m = find_metric(&metrics, "windmill.queue.running_count").unwrap();
+    let values = gauge_i64_values(m);
+    let dp = values
+        .iter()
+        .find(|(attrs, _)| {
+            attrs
+                .iter()
+                .any(|kv| kv.key.as_str() == "tag" && kv.value.as_str() == "deno")
+        })
+        .expect("running_count data point with tag=deno not found");
+    assert_eq!(dp.1, 5);
+
+    let m = find_metric(&metrics, "windmill.worker.busy").unwrap();
+    let values = gauge_i64_values(m);
+    let dp = values
+        .iter()
+        .find(|(attrs, _)| {
+            attrs
+                .iter()
+                .any(|kv| kv.key.as_str() == "worker" && kv.value.as_str() == "worker-test-1")
+        })
+        .expect("worker.busy data point with worker=worker-test-1 not found");
+    assert_eq!(dp.1, 1);
+
+    let m = find_metric(&metrics, "windmill.db.pool.active").unwrap();
+    assert_eq!(gauge_i64_values(m)[0].1, 5);
+    let m = find_metric(&metrics, "windmill.db.pool.idle").unwrap();
+    assert_eq!(gauge_i64_values(m)[0].1, 10);
+    let m = find_metric(&metrics, "windmill.db.pool.max").unwrap();
+    assert_eq!(gauge_i64_values(m)[0].1, 20);
+
+    let m = find_metric(&metrics, "windmill.health.db_latency").unwrap();
+    assert!((gauge_f64_value(m).unwrap() - 2.5).abs() < f64::EPSILON);
+
+    let m = find_metric(&metrics, "windmill.worker.uptime").unwrap();
+    assert!((gauge_f64_value(m).unwrap() - 3600.0).abs() < f64::EPSILON);
+
+    let m = find_metric(&metrics, "windmill.health.db_unresponsive").unwrap();
+    assert_eq!(gauge_i64_values(m)[0].1, 1);
+
+    // ── Health status phase (all 3 phases) ──────────────────────────
+
+    let m = find_metric(&metrics, "windmill.health.status").unwrap();
+    let values = gauge_i64_values(m);
+    let healthy = values
+        .iter()
+        .find(|(attrs, _)| {
+            attrs
+                .iter()
+                .any(|kv| kv.key.as_str() == "phase" && kv.value.as_str() == "healthy")
+        })
+        .expect("phase=healthy");
+    let degraded = values
+        .iter()
+        .find(|(attrs, _)| {
+            attrs
+                .iter()
+                .any(|kv| kv.key.as_str() == "phase" && kv.value.as_str() == "degraded")
+        })
+        .expect("phase=degraded");
+    let unhealthy = values
+        .iter()
+        .find(|(attrs, _)| {
+            attrs
+                .iter()
+                .any(|kv| kv.key.as_str() == "phase" && kv.value.as_str() == "unhealthy")
+        })
+        .expect("phase=unhealthy");
+    assert_eq!(healthy.1, 1);
+    assert_eq!(degraded.1, 0);
+    assert_eq!(unhealthy.1, 0);
+
+    // ── Histogram values ────────────────────────────────────────────
+
+    let m = find_metric(&metrics, "windmill.worker.execution_duration").unwrap();
+    assert!(histogram_f64_count(m).unwrap() >= 2);
+    assert!(histogram_f64_sum(m).unwrap() >= 4.0);
+
+    let m = find_metric(&metrics, "windmill.worker.pull_duration").unwrap();
+    assert!(histogram_f64_count(m).unwrap() >= 2);
+}
+
+// ═══════════════════════════════════════════════════════════════════════
+// SPAN E2E TESTS
+// ═══════════════════════════════════════════════════════════════════════
+
+fn make_test_job(id: uuid::Uuid, parent: Option<uuid::Uuid>) -> windmill_queue::MiniPulledJob {
+    use windmill_types::jobs::JobKind;
+    let mut job = windmill_queue::MiniPulledJob::new_inline(
+        "test-workspace".to_string(),
+        None,
+        "test-user".to_string(),
+        "u/test-user".to_string(),
+        "test@example.com".to_string(),
+        Some("f/test/script".to_string()),
+        JobKind::Script,
+        None,
+        "deno".to_string(),
+        None,
+    );
+    job.id = id;
+    job.parent_job = parent;
+    job.started_at = Some(chrono::Utc::now());
+    job
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn test_root_job_span_created_on_success() {
+    let state = ensure_setup().await;
+    state.span_exporter.reset();
+
+    let job_id = uuid::Uuid::new_v4();
+    let job = make_test_job(job_id, None);
+    windmill_worker::otel_ee::add_root_flow_job_to_otlp(&job, true);
+
+    let spans = state.span_exporter.get_finished_spans().unwrap();
+    let span = spans
+        .iter()
+        .find(|s| s.name == "full_job")
+        .expect("full_job span not found");
+
+    assert_eq!(span.status, opentelemetry::trace::Status::Ok,);
+
+    // Verify attributes
+    let attrs: Vec<_> = span.attributes.iter().map(|kv| kv.key.as_str()).collect();
+    assert!(attrs.contains(&"job_id"), "missing job_id attribute");
+    assert!(
+        attrs.contains(&"workspace_id"),
+        "missing workspace_id attribute"
+    );
+    assert!(
+        attrs.contains(&"script_path"),
+        "missing script_path attribute"
+    );
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn test_root_job_span_error_on_failure() {
+    let state = ensure_setup().await;
+    state.span_exporter.reset();
+
+    let job_id = uuid::Uuid::new_v4();
+    let job = make_test_job(job_id, None);
+    windmill_worker::otel_ee::add_root_flow_job_to_otlp(&job, false);
+
+    let spans = state.span_exporter.get_finished_spans().unwrap();
+    let span = spans
+        .iter()
+        .find(|s| s.name == "full_job")
+        .expect("full_job span not found");
+
+    match &span.status {
+        opentelemetry::trace::Status::Error { description } => {
+            assert_eq!(description.as_ref(), "Job failed");
+        }
+        other => panic!("expected Error status, got {:?}", other),
+    }
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn test_root_job_trace_id_matches_uuid() {
+    let state = ensure_setup().await;
+    state.span_exporter.reset();
+
+    let job_id = uuid::Uuid::parse_str("550e8400-e29b-41d4-a716-446655440000").unwrap();
+    let job = make_test_job(job_id, None);
+    windmill_worker::otel_ee::add_root_flow_job_to_otlp(&job, true);
+
+    let spans = state.span_exporter.get_finished_spans().unwrap();
+    let span = spans
+        .iter()
+        .find(|s| s.name == "full_job")
+        .expect("full_job span not found");
+
+    let expected_trace_id =
+        opentelemetry::trace::TraceId::from_bytes(job_id.as_u128().to_be_bytes());
+    assert_eq!(span.span_context.trace_id(), expected_trace_id);
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn test_root_job_span_id_matches_uuid() {
+    let state = ensure_setup().await;
+    state.span_exporter.reset();
+
+    let job_id = uuid::Uuid::parse_str("550e8400-e29b-41d4-a716-446655440000").unwrap();
+    let job = make_test_job(job_id, None);
+    windmill_worker::otel_ee::add_root_flow_job_to_otlp(&job, true);
+
+    let spans = state.span_exporter.get_finished_spans().unwrap();
+    let span = spans
+        .iter()
+        .find(|s| s.name == "full_job")
+        .expect("full_job span not found");
+
+    let expected_span_id =
+        opentelemetry::trace::SpanId::from_bytes(job_id.as_u64_pair().1.to_be_bytes());
+    assert_eq!(span.span_context.span_id(), expected_span_id);
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn test_child_job_produces_no_span() {
+    let state = ensure_setup().await;
+    state.span_exporter.reset();
+
+    let parent_id = uuid::Uuid::new_v4();
+    let job_id = uuid::Uuid::new_v4();
+    let job = make_test_job(job_id, Some(parent_id));
+    windmill_worker::otel_ee::add_root_flow_job_to_otlp(&job, true);
+
+    let spans = state.span_exporter.get_finished_spans().unwrap();
+    let found = spans.iter().any(|s| s.name == "full_job");
+    assert!(!found, "child job should not produce a span");
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn test_root_job_span_attributes_values() {
+    let state = ensure_setup().await;
+    state.span_exporter.reset();
+
+    let job_id = uuid::Uuid::new_v4();
+    let job = make_test_job(job_id, None);
+    windmill_worker::otel_ee::add_root_flow_job_to_otlp(&job, true);
+
+    let spans = state.span_exporter.get_finished_spans().unwrap();
+    let span = spans
+        .iter()
+        .find(|s| s.name == "full_job")
+        .expect("full_job span not found");
+
+    let get_attr = |key: &str| -> String {
+        span.attributes
+            .iter()
+            .find(|kv| kv.key.as_str() == key)
+            .map(|kv| kv.value.as_str().to_string())
+            .unwrap_or_default()
+    };
+
+    assert_eq!(get_attr("job_id"), job_id.to_string());
+    assert_eq!(get_attr("workspace_id"), "test-workspace");
+    assert_eq!(get_attr("script_path"), "f/test/script");
+}
diff --git a/backend/windmill-common/src/otel_oss.rs b/backend/windmill-common/src/otel_oss.rs
index 3710464607..27c7101dc0 100644
--- a/backend/windmill-common/src/otel_oss.rs
+++ b/backend/windmill-common/src/otel_oss.rs
@@ -59,7 +59,7 @@ pub(crate) fn init_otlp_tracer(
     _mode: &Mode,
     _hostname: &str,
     _env: &str,
-) -> Option<opentelemetry_sdk::trace::Tracer> {
+) -> Option<opentelemetry_sdk::trace::SdkTracer> {
     None
 }
 
diff --git a/backend/windmill-common/src/tracing_init.rs b/backend/windmill-common/src/tracing_init.rs
index 3b009a36eb..1a2ca33518 100644
--- a/backend/windmill-common/src/tracing_init.rs
+++ b/backend/windmill-common/src/tracing_init.rs
@@ -273,3 +273,4 @@ where
         }
     }
 }
+
diff --git a/backend/windmill-worker/src/worker.rs b/backend/windmill-worker/src/worker.rs
index b75403bef7..8aeb3a9e5e 100644
--- a/backend/windmill-worker/src/worker.rs
+++ b/backend/windmill-worker/src/worker.rs
@@ -5412,3 +5412,4 @@ pub fn get_worker_internal_server_inline_utils(
         )),
     }
 }
+