diff --git a/validator_client/src/block_producer/mod.rs b/validator_client/src/block_producer/mod.rs
index 2efcbd6ef8..db65ee7896 100644
--- a/validator_client/src/block_producer/mod.rs
+++ b/validator_client/src/block_producer/mod.rs
@@ -1,11 +1,11 @@
 mod grpc;
 mod service;
+#[cfg(test)]
 mod test_node;
 mod traits;
 
 use self::traits::{BeaconNode, BeaconNodeError};
 use super::EpochDutiesMap;
-use crate::duties::EpochDuties;
 use slot_clock::SlotClock;
 use spec::ChainSpec;
 use std::sync::{Arc, RwLock};
@@ -139,6 +139,7 @@ mod tests {
     use super::*;
     use slot_clock::TestingSlotClock;
     use types::test_utils::{SeedableRng, TestRandom, XorShiftRng};
+    use crate::duties::EpochDuties;
 
     // TODO: implement more thorough testing.
     //
diff --git a/validator_client/src/duties/grpc.rs b/validator_client/src/duties/grpc.rs
index 4032d49f3e..4ea9c6d41e 100644
--- a/validator_client/src/duties/grpc.rs
+++ b/validator_client/src/duties/grpc.rs
@@ -1,63 +1,34 @@
+use super::EpochDuties;
 use super::traits::{BeaconNode, BeaconNodeError};
-use protos::services::{
-    BeaconBlock as GrpcBeaconBlock, ProduceBeaconBlockRequest, PublishBeaconBlockRequest,
-};
+use protos::services::ValidatorAssignmentRequest;
 use protos::services_grpc::BeaconBlockServiceClient;
-use ssz::{ssz_encode, Decodable};
-use types::{BeaconBlock, BeaconBlockBody, Hash256, Signature};
+use ssz::ssz_encode;
+use types::{PublicKey};
 
 impl BeaconNode for BeaconBlockServiceClient {
-    fn produce_beacon_block(&self, slot: u64) -> Result<Option<BeaconBlock>, BeaconNodeError> {
-        let mut req = ProduceBeaconBlockRequest::new();
-        req.set_slot(slot);
+    fn request_shuffling(&self, epoch: u64, public_key: &PublicKey) -> Result<Option<EpochDuties>, BeaconNodeError> {
+        let mut req = ValidatorAssignmentRequest::new();
+        req.set_epoch(epoch);
+        req.set_public_key(ssz_encode(public_key).to_vec());
 
         let reply = self
-            .produce_beacon_block(&req)
+            .validator_assignment(&req)
             .map_err(|err| BeaconNodeError::RemoteFailure(format!("{:?}", err)))?;
 
-        if reply.has_block() {
-            let block = reply.get_block();
+        if reply.has_validator_assignment() {
+            let assignment = reply.get_validator_assignment();
 
-            let (signature, _) = Signature::ssz_decode(block.get_signature(), 0)
-                .map_err(|_| BeaconNodeError::DecodeFailure)?;
+            let block_production_slot = if assignment.has_block_production_slot() {
+                Some(assignment.get_block_production_slot())
+            } else {
+                None
+            };
 
-            // TODO: this conversion is incomplete; fix it.
-            Ok(Some(BeaconBlock {
-                slot: block.get_slot(),
-                parent_root: Hash256::zero(),
-                state_root: Hash256::zero(),
-                randao_reveal: Hash256::from(block.get_randao_reveal()),
-                candidate_pow_receipt_root: Hash256::zero(),
-                signature,
-                body: BeaconBlockBody {
-                    proposer_slashings: vec![],
-                    casper_slashings: vec![],
-                    attestations: vec![],
-                    deposits: vec![],
-                    exits: vec![],
-                },
-            }))
+            let duties = EpochDuties { block_production_slot };
+
+            Ok(Some(duties))
         } else {
             Ok(None)
         }
     }
-
-    fn publish_beacon_block(&self, block: BeaconBlock) -> Result<bool, BeaconNodeError> {
-        let mut req = PublishBeaconBlockRequest::new();
-
-        // TODO: this conversion is incomplete; fix it.
-        let mut grpc_block = GrpcBeaconBlock::new();
-        grpc_block.set_slot(block.slot);
-        grpc_block.set_block_root(vec![0]);
-        grpc_block.set_randao_reveal(block.randao_reveal.to_vec());
-        grpc_block.set_signature(ssz_encode(&block.signature));
-
-        req.set_block(grpc_block);
-
-        let reply = self
-            .publish_beacon_block(&req)
-            .map_err(|err| BeaconNodeError::RemoteFailure(format!("{:?}", err)))?;
-
-        Ok(reply.get_success())
-    }
 }
diff --git a/validator_client/src/duties/mod.rs b/validator_client/src/duties/mod.rs
index d401d350e9..0ac14b07f5 100644
--- a/validator_client/src/duties/mod.rs
+++ b/validator_client/src/duties/mod.rs
@@ -1,3 +1,9 @@
+mod grpc;
+mod service;
+#[cfg(test)]
+mod test_node;
+mod traits;
+
 use self::traits::{BeaconNode, BeaconNodeError};
 use bls::PublicKey;
 use slot_clock::SlotClock;
@@ -5,10 +11,6 @@ use spec::ChainSpec;
 use std::collections::HashMap;
 use std::sync::{Arc, RwLock};
 
-mod service;
-mod test_node;
-mod traits;
-
 pub use self::service::DutiesManagerService;
 
 #[derive(Debug, PartialEq, Clone, Copy, Default)]
diff --git a/validator_client/src/duties/traits.rs b/validator_client/src/duties/traits.rs
index eb0f1583e4..14c2adf954 100644
--- a/validator_client/src/duties/traits.rs
+++ b/validator_client/src/duties/traits.rs
@@ -4,7 +4,6 @@ use bls::PublicKey;
 #[derive(Debug, PartialEq, Clone)]
 pub enum BeaconNodeError {
     RemoteFailure(String),
-    DecodeFailure,
 }
 
 pub trait BeaconNode: Send + Sync {
diff --git a/validator_client/src/main.rs b/validator_client/src/main.rs
index 179146897f..187b40f04b 100644
--- a/validator_client/src/main.rs
+++ b/validator_client/src/main.rs
@@ -96,6 +96,25 @@ fn main() {
     for keypair in keypairs {
         let duties_map = Arc::new(RwLock::new(EpochDutiesMap::new()));
 
+        let duties_manager_thread = {
+            let spec = spec.clone();
+            let duties_map = duties_map.clone();
+            let slot_clock = slot_clock.clone();
+            let log = log.clone();
+            let beacon_node = client.clone();
+            let pubkey = keypair.pk.clone();
+            thread::spawn(move || {
+                let manager = DutiesManager { duties_map, pubkey, spec, slot_clock, beacon_node };
+                let mut duties_manager_service = DutiesManagerService {
+                    manager,
+                    poll_interval_millis,
+                    log,
+                };
+
+                duties_manager_service.run();
+            })
+        };
+
         let producer_thread = {
             let spec = spec.clone();
             let duties_map = duties_map.clone();
@@ -113,11 +132,13 @@ fn main() {
                 block_producer_service.run();
             })
         };
-        threads.push(((), producer_thread));
+
+        threads.push((duties_manager_thread, producer_thread));
     }
 
     for tuple in threads {
         let (manager, producer) = tuple;
         let _ = producer.join();
+        let _ = manager.join();
     }
 }