diff --git a/stake_aggregate/src/epoch.rs b/stake_aggregate/src/epoch.rs
index bd03108..2257490 100644
--- a/stake_aggregate/src/epoch.rs
+++ b/stake_aggregate/src/epoch.rs
@@ -7,10 +7,92 @@ use solana_client::nonblocking::rpc_client::RpcClient;
 use solana_sdk::commitment_config::{CommitmentConfig, CommitmentLevel};
 use solana_sdk::epoch_info::EpochInfo;
 use solana_sdk::sysvar::epoch_schedule::EpochSchedule;
+use std::collections::BTreeMap;
+use std::collections::BTreeSet;
+use std::ops::Bound;
 use std::sync::Arc;
 use yellowstone_grpc_proto::geyser::CommitmentLevel as GeyserCommitmentLevel;
+use yellowstone_grpc_proto::prelude::SubscribeUpdateBlock;
 use yellowstone_grpc_proto::prelude::SubscribeUpdateSlot;
 
+#[derive(Debug)]
+pub struct BlockSlotVerifier {
+    block_cache: BTreeMap<u64, SubscribeUpdateBlock>,
+    slot_cache: BTreeSet<u64>,
+}
+
+impl BlockSlotVerifier {
+    pub fn new() -> Self {
+        BlockSlotVerifier {
+            block_cache: BTreeMap::new(),
+            slot_cache: BTreeSet::new(),
+        }
+    }
+    pub fn process_slot(&mut self, slot: u64) -> Option<(u64, SubscribeUpdateBlock)> {
+        match self.block_cache.remove(&slot) {
+            //the block is already seen. Return slot/block.
+            Some(block) => Some((slot, block)),
+            None => {
+                self.slot_cache.insert(slot);
+                self.verify(slot);
+                None
+            }
+        }
+    }
+    pub fn process_block(
+        &mut self,
+        block: SubscribeUpdateBlock,
+    ) -> Option<(u64, SubscribeUpdateBlock)> {
+        let slot = block.slot;
+        if self.slot_cache.remove(&slot) {
+            //the slot is already seen. Return slot/block.
+            Some((slot, block))
+        } else {
+            //Cache block and  wait  for the slot
+            let old = self.block_cache.insert(slot, block);
+            if old.is_some() {
+                log::warn!("Receive 2 blocks for the same slot:{slot}");
+            }
+            None
+        }
+    }
+
+    fn verify(&mut self, current_slot: u64) {
+        //do some verification on cached block and slot
+        let old_slot: Vec<_> = self
+            .slot_cache
+            .range((
+                Bound::Unbounded,
+                Bound::Included(current_slot.saturating_sub(2)),
+            ))
+            .copied()
+            .collect();
+        if old_slot.len() > 0 {
+            log::error!("Missing block for slots:{:?}", old_slot);
+            for slot in &old_slot {
+                self.slot_cache.remove(&slot);
+            }
+        }
+
+        //verify that there's no too old block.
+        let old_block_slots: Vec<_> = self
+            .block_cache
+            .range((
+                Bound::Unbounded,
+                Bound::Included(current_slot.saturating_sub(2)),
+            ))
+            .map(|(slot, _)| slot)
+            .copied()
+            .collect();
+        if old_block_slots.len() > 0 {
+            log::error!("Missing slot for block  slot:{:?}", old_slot);
+            for slot in old_block_slots {
+                self.block_cache.remove(&slot);
+            }
+        }
+    }
+}
+
 #[derive(Debug, Default, Copy, Clone, PartialOrd, PartialEq, Eq, Ord, Serialize, Deserialize)]
 pub struct Epoch {
     pub epoch: u64,
diff --git a/stake_aggregate/src/main.rs b/stake_aggregate/src/main.rs
index 6526b75..cd5479b 100644
--- a/stake_aggregate/src/main.rs
+++ b/stake_aggregate/src/main.rs
@@ -36,6 +36,7 @@ curl http://localhost:3001 -X POST -H "Content-Type: application/json" -d '
 
 use crate::bootstrap::BootstrapData;
 use crate::bootstrap::BootstrapEvent;
+use crate::epoch::BlockSlotVerifier;
 use crate::leader_schedule::LeaderScheduleData;
 use crate::stakestore::StakeStore;
 use crate::votestore::VoteStore;
@@ -261,7 +262,7 @@ async fn run_loop<F: Interceptor>(mut client: GeyserGrpcClient<F>) -> anyhow::Re
     //use  to process block at confirm slot.
     //at confirm  slot are send before the block.
     //Verify  that  the  last confirmed slot receive  is the  block slot.
-    let mut last_confirmed_slot = 0;
+    let mut block_slot_verifier = BlockSlotVerifier::new();
     loop {
         tokio::select! {
             Some(req) = request_rx.recv() => {
@@ -414,9 +415,10 @@ async fn run_loop<F: Interceptor>(mut client: GeyserGrpcClient<F>) -> anyhow::Re
 
                                         if let CommitmentLevel::Confirmed = slot.status() {
                                             log::trace!("Receive confirmed slot:{}", slot.slot);
-                                            last_confirmed_slot =  slot.slot;
+                                            if let  Some((slot,  block)) =  block_slot_verifier.process_slot(slot.slot) {
+                                                process_block(block, slot);
+                                            }
                                         }
-
                                     }
                                     Some(UpdateOneof::BlockMeta(block_meta)) => {
                                         log::info!("Receive Block Meta at slot: {}", block_meta.slot);
@@ -428,11 +430,9 @@ async fn run_loop<F: Interceptor>(mut client: GeyserGrpcClient<F>) -> anyhow::Re
                                             block.parent_slot,
                                         );
 
-                                        let  slot  = block.slot;
-                                        if last_confirmed_slot != 0 && last_confirmed_slot  != slot  {
-                                            log::error!("No block found for slot:{last_confirmed_slot}. Get bloc for slot:{slot}");
+                                        if let  Some((slot,  block)) =  block_slot_verifier.process_block(block) {
+                                            process_block(block, slot);
                                         }
-                                        process_block(block, slot);
 
                                     }
                                     Some(UpdateOneof::Ping(_)) => log::trace!("UpdateOneof::Ping"),