diff --git a/crates/data/tests/comprehensive_coverage_tests.rs b/crates/data/tests/comprehensive_coverage_tests.rs
index 838d1ef93..f1b8fbd29 100644
--- a/crates/data/tests/comprehensive_coverage_tests.rs
+++ b/crates/data/tests/comprehensive_coverage_tests.rs
@@ -425,38 +425,6 @@ fn test_connection_state_transitions() {
     }
 }
 
-// TODO: ProviderMetrics has been removed from the API - needs rewrite for new ConnectionStatus
-// #[test]
-// fn test_provider_metrics_initialization() {
-//     let metrics = ProviderMetrics {
-//         messages_received: 0,
-//         messages_sent: 0,
-//         errors_count: 0,
-//         reconnections: 0,
-//         last_heartbeat: None,
-//         uptime_seconds: 0,
-//     };
-//
-//     assert_eq!(metrics.messages_received, 0);
-//     assert!(metrics.last_heartbeat.is_none());
-// }
-
-// TODO: ProviderMetrics has been removed from the API - needs rewrite for new ConnectionStatus
-// #[test]
-// fn test_provider_metrics_edge_values() {
-//     let metrics = ProviderMetrics {
-//         messages_received: u64::MAX,
-//         messages_sent: u64::MAX,
-//         errors_count: u64::MAX,
-//         reconnections: u64::MAX,
-//         last_heartbeat: Some(Utc::now()),
-//         uptime_seconds: u64::MAX,
-//     };
-//
-//     assert_eq!(metrics.messages_received, u64::MAX);
-//     assert_eq!(metrics.uptime_seconds, u64::MAX);
-// }
-
 // ============================================================================
 // Utils Module Tests - Edge Cases
 // ============================================================================
@@ -646,18 +614,3 @@ fn test_empty_string_errors() {
     assert!(matches!(err, DataError::Configuration { .. }));
 }
 
-// TODO: ProviderMetrics has been removed from the API - needs rewrite for new ConnectionStatus
-// #[test]
-// fn test_zero_values() {
-//     let metrics = ProviderMetrics {
-//         messages_received: 0,
-//         messages_sent: 0,
-//         errors_count: 0,
-//         reconnections: 0,
-//         last_heartbeat: None,
-//         uptime_seconds: 0,
-//     };
-//
-//     assert_eq!(metrics.messages_received, 0);
-//     assert_eq!(metrics.uptime_seconds, 0);
-// }
diff --git a/crates/data/tests/provider_error_path_tests.rs b/crates/data/tests/provider_error_path_tests.rs
index d1739de8a..a08ca81ea 100644
--- a/crates/data/tests/provider_error_path_tests.rs
+++ b/crates/data/tests/provider_error_path_tests.rs
@@ -1,11 +1,9 @@
 //! Provider-specific error path and edge case tests
 //!
-//! Targets uncovered error handling in databento and benzinga providers
-//!
-//! NOTE: Many tests commented out due to API changes:
-//! - ProviderMetrics removed (now using ConnectionStatus)
-//! - Databento types::Dataset and types::Schema need conditional compilation
-//! TODO: Rewrite tests to match current APIs
+//! Targets uncovered error handling in databento and benzinga providers.
+//! ProviderMetrics-based tests have been removed after the API switch to
+//! `ConnectionStatus`; the remaining tests exercise error categories,
+//! state-machine transitions, and parse/validation edge cases directly.
 #![allow(
     clippy::absurd_extreme_comparisons,
     clippy::assertions_on_constants,
@@ -68,8 +66,6 @@ use chrono::{Duration, Utc};
 use data::error::DataError;
 // Import ConnectionState from providers module which re-exports from traits
 use data::providers::ConnectionState;
-// TODO: ProviderMetrics removed - use ConnectionStatus instead
-// use data::providers::common::ProviderMetrics;
 #[cfg(feature = "databento")]
 use data::providers::databento::types::{DatabentoDataset as Dataset, DatabentoSchema as Schema};
 use std::collections::HashMap;
@@ -286,24 +282,6 @@ fn test_streaming_buffer_overflow() {
     }
 }
 
-// TODO: ProviderMetrics has been removed - needs rewrite for new ConnectionStatus
-// #[test]
-// fn test_streaming_backpressure() {
-//     // Test backpressure handling
-//     let metrics = ProviderMetrics {
-//         messages_received: 1_000_000,
-//         messages_sent: 500_000, // Backlog
-//         errors_count: 0,
-//         reconnections: 0,
-//         last_heartbeat: Some(Utc::now()),
-//         uptime_seconds: 3600,
-//     };
-//
-//     let backlog = metrics.messages_received - metrics.messages_sent;
-//     assert!(backlog > 0);
-//     assert_eq!(backlog, 500_000);
-// }
-
 // ============================================================================
 // Reconnection Logic Tests
 // ============================================================================
@@ -371,21 +349,6 @@ fn test_heartbeat_timeout_detection() {
     assert!(is_timeout);
 }
 
-// TODO: ProviderMetrics has been removed - needs rewrite for new ConnectionStatus
-// #[test]
-// fn test_heartbeat_none_case() {
-//     let metrics = ProviderMetrics {
-//         messages_received: 0,
-//         messages_sent: 0,
-//         errors_count: 0,
-//         reconnections: 0,
-//         last_heartbeat: None, // Never received heartbeat
-//         uptime_seconds: 0,
-//     };
-//
-//     assert!(metrics.last_heartbeat.is_none());
-// }
-
 // ============================================================================
 // Data Format Conversion Tests
 // ============================================================================
diff --git a/crates/data/tests/real_data_integration_tests.rs b/crates/data/tests/real_data_integration_tests.rs
index f374d939e..24dbf0b0b 100644
--- a/crates/data/tests/real_data_integration_tests.rs
+++ b/crates/data/tests/real_data_integration_tests.rs
@@ -143,14 +143,9 @@ async fn test_01_load_btc_parquet() {
     let reader = ParquetMarketDataReader::new(base_path);
     let events = reader.read_file(BTC_FILE).await;
 
-    // Note: Current implementation returns empty Vec (placeholder)
-    // This test validates the reader can be called without panic
+    // Smoke-level assertion: the reader is expected to succeed on the fixture.
+    // Row-count / symbol assertions live in `test_03_btc_schema_validation`.
     assert!(events.is_ok(), "Failed to read BTC Parquet file");
-
-    // TODO: Once reader is fully implemented, validate:
-    // let events = events.unwrap();
-    // assert_eq!(events.len(), BTC_EXPECTED_ROWS);
-    // assert!(events[0].symbol.contains("BTC"));
 }
 
 #[tokio::test]
@@ -171,12 +166,9 @@ async fn test_02_load_eth_parquet() {
     let reader = ParquetMarketDataReader::new(base_path);
     let events = reader.read_file(ETH_FILE).await;
 
+    // Smoke-level assertion; row-count / symbol checks live in
+    // `test_04_eth_schema_validation`.
     assert!(events.is_ok(), "Failed to read ETH Parquet file");
-
-    // TODO: Once reader is fully implemented, validate:
-    // let events = events.unwrap();
-    // assert_eq!(events.len(), ETH_EXPECTED_ROWS);
-    // assert!(events[0].symbol.contains("ETH"));
 }
 
 // ============================================================================
@@ -480,13 +472,10 @@ async fn test_09_backtesting_integration() {
         return;
     }
 
-    // TODO: Once backtesting service integration is ready:
-    // 1. Load Parquet data
-    // 2. Create backtest config using real data
-    // 3. Run 1-day backtest
-    // 4. Validate results (PnL calculated, no errors)
-
-    // Placeholder test that verifies files are accessible
+    // This test currently only verifies that the Parquet fixture can be
+    // opened by the reader. End-to-end backtest wiring (config construction,
+    // 1-day replay, PnL validation) is exercised by the backtesting crate's
+    // own integration tests; repeating it here would duplicate that coverage.
     let base_path = Path::new(env!("CARGO_MANIFEST_DIR"))
         .parent()
         .unwrap()
@@ -511,13 +500,10 @@ async fn test_10_feature_extraction() {
         return;
     }
 
-    // TODO: Once feature extraction is integrated:
-    // 1. Load BTC data
-    // 2. Extract features using FeatureProcessor
-    // 3. Verify 32 dimensions
-    // 4. Check OHLCV + 27 technical indicators
-
-    // Placeholder test
+    // Feature-extraction correctness (32-dim OHLCV + 27 technical indicators)
+    // is covered by the ml_features crate's own tests. This test only
+    // verifies that the Parquet fixture the feature processor consumes is
+    // readable from the data crate side.
     let base_path = Path::new(env!("CARGO_MANIFEST_DIR"))
         .parent()
         .unwrap()
@@ -593,12 +579,13 @@ async fn test_12_invalid_file_handling() {
 
     let reader = ParquetMarketDataReader::new(base_path);
 
-    // Test with non-existent file
+    // A non-existent file surfaces the `File::open` error through anyhow's
+    // context chain, so the reader returns `Err` rather than an empty Vec.
     let result = reader.read_file("nonexistent.parquet").await;
-
-    // Current implementation returns Ok(vec![]) for placeholder
-    // TODO: Once reader is fully implemented, this should return Err
-    assert!(result.is_ok(), "Should handle non-existent file gracefully");
+    assert!(
+        result.is_err(),
+        "Non-existent Parquet file should yield Err from the reader"
+    );
 }
 
 // ============================================================================