diff --git a/crates/index-scheduler/src/batch.rs b/crates/index-scheduler/src/batch.rs
index 89c7f6f45..449d2aaed 100644
--- a/crates/index-scheduler/src/batch.rs
+++ b/crates/index-scheduler/src/batch.rs
@@ -839,12 +839,14 @@ impl IndexScheduler {
                             for document in
                                 serde_json::de::Deserializer::from_reader(content_file).into_iter()
                             {
-                                let document = document.map_err(|e| {
-                                    Error::from_milli(
-                                        milli::InternalError::SerdeJson(e).into(),
-                                        None,
-                                    )
-                                })?;
+                                let document = document
+                                    .map_err(|e| {
+                                        Error::from_milli(
+                                            milli::InternalError::SerdeJson(e).into(),
+                                            None,
+                                        )
+                                    })
+                                    .unwrap();
                                 dump_content_file.push_document(&document)?;
                             }
 
diff --git a/crates/index-scheduler/src/index_mapper/index_map.rs b/crates/index-scheduler/src/index_mapper/index_map.rs
index 480dafa7c..931cff162 100644
--- a/crates/index-scheduler/src/index_mapper/index_map.rs
+++ b/crates/index-scheduler/src/index_mapper/index_map.rs
@@ -1,5 +1,7 @@
 use std::collections::BTreeMap;
+use std::env::VarError;
 use std::path::Path;
+use std::str::FromStr;
 use std::time::Duration;
 
 use meilisearch_types::heed::{EnvClosingEvent, EnvFlags, EnvOpenOptions};
@@ -302,7 +304,15 @@ fn create_or_open_index(
 ) -> Result<Index> {
     let mut options = EnvOpenOptions::new();
     options.map_size(clamp_to_page_size(map_size));
-    options.max_readers(1024);
+
+    let max_readers = match std::env::var("MEILI_EXPERIMENTAL_INDEX_MAX_READERS") {
+        Ok(value) => u32::from_str(&value).unwrap(),
+        Err(VarError::NotPresent) => 1024,
+        Err(VarError::NotUnicode(value)) => panic!(
+            "Invalid unicode for the `MEILI_EXPERIMENTAL_INDEX_MAX_READERS` env var: {value:?}"
+        ),
+    };
+    options.max_readers(max_readers);
     if enable_mdb_writemap {
         unsafe { options.flags(EnvFlags::WRITE_MAP) };
     }
diff --git a/crates/index-scheduler/src/lib.rs b/crates/index-scheduler/src/lib.rs
index ac51e584a..9f2594f31 100644
--- a/crates/index-scheduler/src/lib.rs
+++ b/crates/index-scheduler/src/lib.rs
@@ -2024,9 +2024,11 @@ impl<'a> Dump<'a> {
                 let mut writer = io::BufWriter::new(file);
                 for doc in content_file {
                     let doc = doc?;
-                    serde_json::to_writer(&mut writer, &doc).map_err(|e| {
-                        Error::from_milli(milli::InternalError::SerdeJson(e).into(), None)
-                    })?;
+                    serde_json::to_writer(&mut writer, &doc)
+                        .map_err(|e| {
+                            Error::from_milli(milli::InternalError::SerdeJson(e).into(), None)
+                        })
+                        .unwrap();
                 }
                 let file = writer.into_inner().map_err(|e| e.into_error())?;
                 file.persist()?;
diff --git a/crates/meilisearch/src/search/mod.rs b/crates/meilisearch/src/search/mod.rs
index 674ae226b..2aec59d2e 100644
--- a/crates/meilisearch/src/search/mod.rs
+++ b/crates/meilisearch/src/search/mod.rs
@@ -1337,7 +1337,7 @@ impl<'a> HitMaker<'a> {
                     ExplicitVectors { embeddings: Some(vector.into()), regenerate: !user_provided };
                 vectors.insert(
                     name,
-                    serde_json::to_value(embeddings).map_err(InternalError::SerdeJson)?,
+                    serde_json::to_value(embeddings).map_err(InternalError::SerdeJson).unwrap(),
                 );
             }
             document.insert("_vectors".into(), vectors.into());
@@ -1717,7 +1717,7 @@ fn make_document(
 
     // recreate the original json
     for (key, value) in obkv.iter() {
-        let value = serde_json::from_slice(value).map_err(InternalError::SerdeJson)?;
+        let value = serde_json::from_slice(value).map_err(InternalError::SerdeJson).unwrap();
         let key = field_ids_map.name(key).expect("Missing field name").to_string();
 
         document.insert(key, value);
diff --git a/crates/milli/src/documents/mod.rs b/crates/milli/src/documents/mod.rs
index 88fa38d30..91dcd348e 100644
--- a/crates/milli/src/documents/mod.rs
+++ b/crates/milli/src/documents/mod.rs
@@ -33,7 +33,7 @@ pub fn obkv_to_object(obkv: &KvReader<FieldId>, index: &DocumentsBatchIndex) ->
             let field_name = index
                 .name(field_id)
                 .ok_or(FieldIdMapMissingEntry::FieldId { field_id, process: "obkv_to_object" })?;
-            let value = serde_json::from_slice(value).map_err(InternalError::SerdeJson)?;
+            let value = serde_json::from_slice(value).map_err(InternalError::SerdeJson).unwrap();
             Ok((field_name.to_string(), value))
         })
         .collect()
@@ -84,7 +84,8 @@ impl DocumentsBatchIndex {
             let key =
                 self.0.get_by_left(&k).ok_or(crate::error::InternalError::DatabaseClosing)?.clone();
             let value = serde_json::from_slice::<serde_json::Value>(v)
-                .map_err(crate::error::InternalError::SerdeJson)?;
+                .map_err(crate::error::InternalError::SerdeJson)
+                .unwrap();
             map.insert(key, value);
         }
 
diff --git a/crates/milli/src/documents/primary_key.rs b/crates/milli/src/documents/primary_key.rs
index c1dd9a9b8..b8d151922 100644
--- a/crates/milli/src/documents/primary_key.rs
+++ b/crates/milli/src/documents/primary_key.rs
@@ -92,7 +92,8 @@ impl<'a> PrimaryKey<'a> {
             PrimaryKey::Flat { name: _, field_id } => match document.get(*field_id) {
                 Some(document_id_bytes) => {
                     let document_id = serde_json::from_slice(document_id_bytes)
-                        .map_err(InternalError::SerdeJson)?;
+                        .map_err(InternalError::SerdeJson)
+                        .unwrap();
                     match validate_document_id_value(document_id) {
                         Ok(document_id) => Ok(Ok(document_id)),
                         Err(user_error) => {
@@ -108,7 +109,8 @@ impl<'a> PrimaryKey<'a> {
                     if let Some(field_id) = fields.id(first_level_name) {
                         if let Some(value_bytes) = document.get(field_id) {
                             let object = serde_json::from_slice(value_bytes)
-                                .map_err(InternalError::SerdeJson)?;
+                                .map_err(InternalError::SerdeJson)
+                                .unwrap();
                             fetch_matching_values(object, right, &mut matching_documents_ids);
 
                             if matching_documents_ids.len() >= 2 {
@@ -151,11 +153,12 @@ impl<'a> PrimaryKey<'a> {
                 };
 
                 let document_id: &RawValue =
-                    serde_json::from_slice(document_id).map_err(InternalError::SerdeJson)?;
+                    serde_json::from_slice(document_id).map_err(InternalError::SerdeJson).unwrap();
 
                 let document_id = document_id
                     .deserialize_any(crate::update::new::indexer::de::DocumentIdVisitor(indexer))
-                    .map_err(InternalError::SerdeJson)?;
+                    .map_err(InternalError::SerdeJson)
+                    .unwrap();
 
                 let external_document_id = match document_id {
                     Ok(document_id) => Ok(document_id),
@@ -173,7 +176,7 @@ impl<'a> PrimaryKey<'a> {
 
                     let Some(value) = document.get(fid) else { continue };
                     let value: &RawValue =
-                        serde_json::from_slice(value).map_err(InternalError::SerdeJson)?;
+                        serde_json::from_slice(value).map_err(InternalError::SerdeJson).unwrap();
                     match match_component(first_level, right, value, indexer, &mut docid) {
                         ControlFlow::Continue(()) => continue,
                         ControlFlow::Break(Ok(_)) => {
@@ -183,7 +186,7 @@ impl<'a> PrimaryKey<'a> {
                             .into())
                         }
                         ControlFlow::Break(Err(err)) => {
-                            return Err(InternalError::SerdeJson(err).into())
+                            panic!("{err}");
                         }
                     }
                 }
diff --git a/crates/milli/src/lib.rs b/crates/milli/src/lib.rs
index 3ae0bfdb9..1e90b50e5 100644
--- a/crates/milli/src/lib.rs
+++ b/crates/milli/src/lib.rs
@@ -228,7 +228,8 @@ pub fn obkv_to_json(
                 field_id: id,
                 process: "obkv_to_json",
             })?;
-            let value = serde_json::from_slice(value).map_err(error::InternalError::SerdeJson)?;
+            let value =
+                serde_json::from_slice(value).map_err(error::InternalError::SerdeJson).unwrap();
             Ok((name.to_owned(), value))
         })
         .collect()
diff --git a/crates/milli/src/thread_pool_no_abort.rs b/crates/milli/src/thread_pool_no_abort.rs
index 14e5b0491..b57050a63 100644
--- a/crates/milli/src/thread_pool_no_abort.rs
+++ b/crates/milli/src/thread_pool_no_abort.rs
@@ -1,4 +1,4 @@
-use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::atomic::{AtomicBool, AtomicUsize, Ordering};
 use std::sync::Arc;
 
 use rayon::{ThreadPool, ThreadPoolBuilder};
@@ -9,6 +9,8 @@ use thiserror::Error;
 #[derive(Debug)]
 pub struct ThreadPoolNoAbort {
     thread_pool: ThreadPool,
+    /// The number of active operations.
+    active_operations: AtomicUsize,
     /// Set to true if the thread pool catched a panic.
     pool_catched_panic: Arc<AtomicBool>,
 }
@@ -19,7 +21,9 @@ impl ThreadPoolNoAbort {
         OP: FnOnce() -> R + Send,
         R: Send,
     {
+        self.active_operations.fetch_add(1, Ordering::Relaxed);
         let output = self.thread_pool.install(op);
+        self.active_operations.fetch_sub(1, Ordering::Relaxed);
         // While reseting the pool panic catcher we return an error if we catched one.
         if self.pool_catched_panic.swap(false, Ordering::SeqCst) {
             Err(PanicCatched)
@@ -31,6 +35,11 @@ impl ThreadPoolNoAbort {
     pub fn current_num_threads(&self) -> usize {
         self.thread_pool.current_num_threads()
     }
+
+    /// The number of active operations.
+    pub fn active_operations(&self) -> usize {
+        self.active_operations.load(Ordering::Relaxed)
+    }
 }
 
 #[derive(Error, Debug)]
@@ -64,6 +73,10 @@ impl ThreadPoolNoAbortBuilder {
             let catched_panic = pool_catched_panic.clone();
             move |_result| catched_panic.store(true, Ordering::SeqCst)
         });
-        Ok(ThreadPoolNoAbort { thread_pool: self.0.build()?, pool_catched_panic })
+        Ok(ThreadPoolNoAbort {
+            thread_pool: self.0.build()?,
+            active_operations: AtomicUsize::new(0),
+            pool_catched_panic,
+        })
     }
 }
diff --git a/crates/milli/src/update/index_documents/enrich.rs b/crates/milli/src/update/index_documents/enrich.rs
index 85f871830..1626adcd9 100644
--- a/crates/milli/src/update/index_documents/enrich.rs
+++ b/crates/milli/src/update/index_documents/enrich.rs
@@ -123,7 +123,8 @@ pub fn enrich_documents_batch<R: Read + Seek>(
             }
         }
 
-        let document_id = serde_json::to_vec(&document_id).map_err(InternalError::SerdeJson)?;
+        let document_id =
+            serde_json::to_vec(&document_id).map_err(InternalError::SerdeJson).unwrap();
         external_ids.insert(count.to_be_bytes(), document_id)?;
 
         count += 1;
@@ -237,7 +238,7 @@ pub fn validate_geo_from_json(id: &DocumentId, bytes: &[u8]) -> Result<StdResult
     let debug_id = || {
         serde_json::from_slice(id.value().as_bytes()).unwrap_or_else(|_| Value::from(id.debug()))
     };
-    match serde_json::from_slice(bytes).map_err(InternalError::SerdeJson)? {
+    match serde_json::from_slice(bytes).map_err(InternalError::SerdeJson).unwrap() {
         Value::Object(mut object) => match (object.remove("lat"), object.remove("lng")) {
             (Some(lat), Some(lng)) => {
                 match (extract_finite_float_from_value(lat), extract_finite_float_from_value(lng)) {
diff --git a/crates/milli/src/update/index_documents/extract/extract_docid_word_positions.rs b/crates/milli/src/update/index_documents/extract/extract_docid_word_positions.rs
index 606ae6b54..9a63e5299 100644
--- a/crates/milli/src/update/index_documents/extract/extract_docid_word_positions.rs
+++ b/crates/milli/src/update/index_documents/extract/extract_docid_word_positions.rs
@@ -206,7 +206,7 @@ fn tokens_from_document<'a>(
             if let Some(field_bytes) = KvReaderDelAdd::from_slice(field_bytes).get(del_add) {
                 // parse json.
                 let value =
-                    serde_json::from_slice(field_bytes).map_err(InternalError::SerdeJson)?;
+                    serde_json::from_slice(field_bytes).map_err(InternalError::SerdeJson).unwrap();
 
                 // prepare writing destination.
                 buffers.obkv_positions_buffer.clear();
diff --git a/crates/milli/src/update/new/document.rs b/crates/milli/src/update/new/document.rs
index 930b0c078..2cce03d87 100644
--- a/crates/milli/src/update/new/document.rs
+++ b/crates/milli/src/update/new/document.rs
@@ -86,7 +86,7 @@ impl<'t, Mapper: FieldIdMapper> Document<'t> for DocumentFromDb<'t, Mapper> {
 
             let res = (|| {
                 let value =
-                    serde_json::from_slice(value).map_err(crate::InternalError::SerdeJson)?;
+                    serde_json::from_slice(value).map_err(crate::InternalError::SerdeJson).unwrap();
 
                 Ok((name, value))
             })();
@@ -139,7 +139,7 @@ impl<'t, Mapper: FieldIdMapper> DocumentFromDb<'t, Mapper> {
             return Ok(None);
         };
         let Some(value) = self.content.get(fid) else { return Ok(None) };
-        Ok(Some(serde_json::from_slice(value).map_err(InternalError::SerdeJson)?))
+        Ok(Some(serde_json::from_slice(value).map_err(InternalError::SerdeJson).unwrap()))
     }
 }
 
diff --git a/crates/milli/src/update/new/extract/faceted/facet_document.rs b/crates/milli/src/update/new/extract/faceted/facet_document.rs
index eff529120..35475e7cc 100644
--- a/crates/milli/src/update/new/extract/faceted/facet_document.rs
+++ b/crates/milli/src/update/new/extract/faceted/facet_document.rs
@@ -27,7 +27,7 @@ pub fn extract_document_facets<'doc>(
         let selection = perm_json_p::select_field(field_name, Some(attributes_to_extract), &[]);
         if selection != perm_json_p::Selection::Skip {
             // parse json.
-            match serde_json::value::to_value(value).map_err(InternalError::SerdeJson)? {
+            match serde_json::value::to_value(value).map_err(InternalError::SerdeJson).unwrap() {
                 Value::Object(object) => {
                     perm_json_p::seek_leaf_values_in_object(
                         &object,
diff --git a/crates/milli/src/update/new/extract/geo/mod.rs b/crates/milli/src/update/new/extract/geo/mod.rs
index a3820609d..438d64d31 100644
--- a/crates/milli/src/update/new/extract/geo/mod.rs
+++ b/crates/milli/src/update/new/extract/geo/mod.rs
@@ -256,15 +256,16 @@ pub fn extract_geo_coordinates(
     external_id: &str,
     raw_value: &RawValue,
 ) -> Result<Option<[f64; 2]>> {
-    let mut geo = match serde_json::from_str(raw_value.get()).map_err(InternalError::SerdeJson)? {
-        Value::Null => return Ok(None),
-        Value::Object(map) => map,
-        value => {
-            return Err(
-                GeoError::NotAnObject { document_id: Value::from(external_id), value }.into()
-            )
-        }
-    };
+    let mut geo =
+        match serde_json::from_str(raw_value.get()).map_err(InternalError::SerdeJson).unwrap() {
+            Value::Null => return Ok(None),
+            Value::Object(map) => map,
+            value => {
+                return Err(
+                    GeoError::NotAnObject { document_id: Value::from(external_id), value }.into()
+                )
+            }
+        };
 
     let [lat, lng] = match (geo.remove("lat"), geo.remove("lng")) {
         (Some(lat), Some(lng)) => {
diff --git a/crates/milli/src/update/new/extract/searchable/tokenize_document.rs b/crates/milli/src/update/new/extract/searchable/tokenize_document.rs
index 1c1605b66..e8c858c9a 100644
--- a/crates/milli/src/update/new/extract/searchable/tokenize_document.rs
+++ b/crates/milli/src/update/new/extract/searchable/tokenize_document.rs
@@ -94,7 +94,7 @@ impl<'a> DocumentTokenizer<'a> {
             };
 
             // parse json.
-            match serde_json::to_value(value).map_err(InternalError::SerdeJson)? {
+            match serde_json::to_value(value).map_err(InternalError::SerdeJson).unwrap() {
                 Value::Object(object) => seek_leaf_values_in_object(
                     &object,
                     None,
diff --git a/crates/milli/src/update/new/indexer/document_operation.rs b/crates/milli/src/update/new/indexer/document_operation.rs
index 5ccac4297..13894c407 100644
--- a/crates/milli/src/update/new/indexer/document_operation.rs
+++ b/crates/milli/src/update/new/indexer/document_operation.rs
@@ -158,7 +158,7 @@ fn extract_addition_payload_changes<'r, 'pl: 'r>(
 
     let mut previous_offset = 0;
     let mut iter = Deserializer::from_slice(payload).into_iter::<&RawValue>();
-    while let Some(doc) = iter.next().transpose().map_err(InternalError::SerdeJson)? {
+    while let Some(doc) = iter.next().transpose().map_err(InternalError::SerdeJson).unwrap() {
         *bytes = previous_offset as u64;
 
         // Only guess the primary key if it is the first document
diff --git a/crates/milli/src/update/new/indexer/partial_dump.rs b/crates/milli/src/update/new/indexer/partial_dump.rs
index 6e4abd898..7fdcdae75 100644
--- a/crates/milli/src/update/new/indexer/partial_dump.rs
+++ b/crates/milli/src/update/new/indexer/partial_dump.rs
@@ -78,7 +78,8 @@ where
         let external_document_id = external_document_id.to_de();
 
         let document = RawMap::from_raw_value_and_hasher(document, FxBuildHasher, doc_alloc)
-            .map_err(InternalError::SerdeJson)?;
+            .map_err(InternalError::SerdeJson)
+            .unwrap();
 
         let insertion = Insertion::create(docid, external_document_id, Versions::single(document));
         Ok(Some(DocumentChange::Insertion(insertion)))
diff --git a/crates/milli/src/update/new/indexer/update_by_function.rs b/crates/milli/src/update/new/indexer/update_by_function.rs
index 3001648e6..3423bde5e 100644
--- a/crates/milli/src/update/new/indexer/update_by_function.rs
+++ b/crates/milli/src/update/new/indexer/update_by_function.rs
@@ -58,9 +58,9 @@ impl UpdateByFunction {
 
         let ast = engine.compile(code).map_err(UserError::DocumentEditionCompilationError)?;
         let context = match context {
-            Some(context) => {
-                Some(serde_json::from_value(context.into()).map_err(InternalError::SerdeJson)?)
-            }
+            Some(context) => Some(
+                serde_json::from_value(context.into()).map_err(InternalError::SerdeJson).unwrap(),
+            ),
             None => None,
         };
 
@@ -137,9 +137,11 @@ impl<'index> DocumentChanges<'index> for UpdateByFunctionChanges<'index> {
                 Some(new_rhai_document) => {
                     let mut buffer = bumpalo::collections::Vec::new_in(doc_alloc);
                     serde_json::to_writer(&mut buffer, &new_rhai_document)
-                        .map_err(InternalError::SerdeJson)?;
+                        .map_err(InternalError::SerdeJson)
+                        .unwrap();
                     let raw_new_doc = serde_json::from_slice(buffer.into_bump_slice())
-                        .map_err(InternalError::SerdeJson)?;
+                        .map_err(InternalError::SerdeJson)
+                        .unwrap();
 
                     // Note: This condition is not perfect. Sometimes it detect changes
                     //       like with floating points numbers and consider updating
@@ -166,7 +168,8 @@ impl<'index> DocumentChanges<'index> for UpdateByFunctionChanges<'index> {
                                 FxBuildHasher,
                                 doc_alloc,
                             )
-                            .map_err(InternalError::SerdeJson)?;
+                            .map_err(InternalError::SerdeJson)
+                            .unwrap();
 
                             Ok(Some(DocumentChange::Update(Update::create(
                                 docid,
@@ -200,7 +203,7 @@ fn obkv_to_rhaimap(obkv: &KvReaderFieldId, fields_ids_map: &FieldsIdsMap) -> Res
                 field_id: id,
                 process: "all_obkv_to_rhaimap",
             })?;
-            let value = serde_json::from_slice(value).map_err(InternalError::SerdeJson)?;
+            let value = serde_json::from_slice(value).map_err(InternalError::SerdeJson).unwrap();
             Ok((name.into(), value))
         })
         .collect();
diff --git a/crates/milli/src/update/new/vector_document.rs b/crates/milli/src/update/new/vector_document.rs
index 8d14a749d..e49cffa57 100644
--- a/crates/milli/src/update/new/vector_document.rs
+++ b/crates/milli/src/update/new/vector_document.rs
@@ -105,7 +105,8 @@ impl<'t> VectorDocumentFromDb<'t> {
         let vectors_field = match vectors {
             Some(vectors) => Some(
                 RawMap::from_raw_value_and_hasher(vectors, FxBuildHasher, doc_alloc)
-                    .map_err(InternalError::SerdeJson)?,
+                    .map_err(InternalError::SerdeJson)
+                    .unwrap(),
             ),
             None => None,
         };
diff --git a/crates/milli/src/vector/ollama.rs b/crates/milli/src/vector/ollama.rs
index 7ee775cbf..a0698c5d0 100644
--- a/crates/milli/src/vector/ollama.rs
+++ b/crates/milli/src/vector/ollama.rs
@@ -5,7 +5,7 @@ use rayon::slice::ParallelSlice as _;
 
 use super::error::{EmbedError, EmbedErrorKind, NewEmbedderError, NewEmbedderErrorKind};
 use super::rest::{Embedder as RestEmbedder, EmbedderOptions as RestEmbedderOptions};
-use super::DistributionShift;
+use super::{DistributionShift, REQUEST_PARALLELISM};
 use crate::error::FaultSource;
 use crate::vector::Embedding;
 use crate::ThreadPoolNoAbort;
@@ -113,20 +113,30 @@ impl Embedder {
         texts: &[&str],
         threads: &ThreadPoolNoAbort,
     ) -> Result<Vec<Vec<f32>>, EmbedError> {
-        threads
-            .install(move || {
-                let embeddings: Result<Vec<Vec<Embedding>>, _> = texts
-                    .par_chunks(self.prompt_count_in_chunk_hint())
-                    .map(move |chunk| self.embed(chunk, None))
-                    .collect();
+        if threads.active_operations() >= REQUEST_PARALLELISM {
+            let embeddings: Result<Vec<Vec<Embedding>>, _> = texts
+                .chunks(self.prompt_count_in_chunk_hint())
+                .map(move |chunk| self.embed(chunk, None))
+                .collect();
 
-                let embeddings = embeddings?;
-                Ok(embeddings.into_iter().flatten().collect())
-            })
-            .map_err(|error| EmbedError {
-                kind: EmbedErrorKind::PanicInThreadPool(error),
-                fault: FaultSource::Bug,
-            })?
+            let embeddings = embeddings?;
+            Ok(embeddings.into_iter().flatten().collect())
+        } else {
+            threads
+                .install(move || {
+                    let embeddings: Result<Vec<Vec<Embedding>>, _> = texts
+                        .par_chunks(self.prompt_count_in_chunk_hint())
+                        .map(move |chunk| self.embed(chunk, None))
+                        .collect();
+
+                    let embeddings = embeddings?;
+                    Ok(embeddings.into_iter().flatten().collect())
+                })
+                .map_err(|error| EmbedError {
+                    kind: EmbedErrorKind::PanicInThreadPool(error),
+                    fault: FaultSource::Bug,
+                })?
+        }
     }
 
     pub fn chunk_count_hint(&self) -> usize {
diff --git a/crates/milli/src/vector/openai.rs b/crates/milli/src/vector/openai.rs
index 7262bfef8..b1af381b1 100644
--- a/crates/milli/src/vector/openai.rs
+++ b/crates/milli/src/vector/openai.rs
@@ -6,7 +6,7 @@ use rayon::slice::ParallelSlice as _;
 
 use super::error::{EmbedError, NewEmbedderError};
 use super::rest::{Embedder as RestEmbedder, EmbedderOptions as RestEmbedderOptions};
-use super::DistributionShift;
+use super::{DistributionShift, REQUEST_PARALLELISM};
 use crate::error::FaultSource;
 use crate::vector::error::EmbedErrorKind;
 use crate::vector::Embedding;
@@ -270,20 +270,29 @@ impl Embedder {
         texts: &[&str],
         threads: &ThreadPoolNoAbort,
     ) -> Result<Vec<Vec<f32>>, EmbedError> {
-        threads
-            .install(move || {
-                let embeddings: Result<Vec<Vec<Embedding>>, _> = texts
-                    .par_chunks(self.prompt_count_in_chunk_hint())
-                    .map(move |chunk| self.embed(chunk, None))
-                    .collect();
+        if threads.active_operations() >= REQUEST_PARALLELISM {
+            let embeddings: Result<Vec<Vec<Embedding>>, _> = texts
+                .chunks(self.prompt_count_in_chunk_hint())
+                .map(move |chunk| self.embed(chunk, None))
+                .collect();
+            let embeddings = embeddings?;
+            Ok(embeddings.into_iter().flatten().collect())
+        } else {
+            threads
+                .install(move || {
+                    let embeddings: Result<Vec<Vec<Embedding>>, _> = texts
+                        .par_chunks(self.prompt_count_in_chunk_hint())
+                        .map(move |chunk| self.embed(chunk, None))
+                        .collect();
 
-                let embeddings = embeddings?;
-                Ok(embeddings.into_iter().flatten().collect())
-            })
-            .map_err(|error| EmbedError {
-                kind: EmbedErrorKind::PanicInThreadPool(error),
-                fault: FaultSource::Bug,
-            })?
+                    let embeddings = embeddings?;
+                    Ok(embeddings.into_iter().flatten().collect())
+                })
+                .map_err(|error| EmbedError {
+                    kind: EmbedErrorKind::PanicInThreadPool(error),
+                    fault: FaultSource::Bug,
+                })?
+        }
     }
 
     pub fn chunk_count_hint(&self) -> usize {
diff --git a/crates/milli/src/vector/rest.rs b/crates/milli/src/vector/rest.rs
index 98be311d4..736dc3b2f 100644
--- a/crates/milli/src/vector/rest.rs
+++ b/crates/milli/src/vector/rest.rs
@@ -203,20 +203,30 @@ impl Embedder {
         texts: &[&str],
         threads: &ThreadPoolNoAbort,
     ) -> Result<Vec<Embedding>, EmbedError> {
-        threads
-            .install(move || {
-                let embeddings: Result<Vec<Vec<Embedding>>, _> = texts
-                    .par_chunks(self.prompt_count_in_chunk_hint())
-                    .map(move |chunk| self.embed_ref(chunk, None))
-                    .collect();
+        if threads.active_operations() >= REQUEST_PARALLELISM {
+            let embeddings: Result<Vec<Vec<Embedding>>, _> = texts
+                .chunks(self.prompt_count_in_chunk_hint())
+                .map(move |chunk| self.embed_ref(chunk, None))
+                .collect();
 
-                let embeddings = embeddings?;
-                Ok(embeddings.into_iter().flatten().collect())
-            })
-            .map_err(|error| EmbedError {
-                kind: EmbedErrorKind::PanicInThreadPool(error),
-                fault: FaultSource::Bug,
-            })?
+            let embeddings = embeddings?;
+            Ok(embeddings.into_iter().flatten().collect())
+        } else {
+            threads
+                .install(move || {
+                    let embeddings: Result<Vec<Vec<Embedding>>, _> = texts
+                        .par_chunks(self.prompt_count_in_chunk_hint())
+                        .map(move |chunk| self.embed_ref(chunk, None))
+                        .collect();
+
+                    let embeddings = embeddings?;
+                    Ok(embeddings.into_iter().flatten().collect())
+                })
+                .map_err(|error| EmbedError {
+                    kind: EmbedErrorKind::PanicInThreadPool(error),
+                    fault: FaultSource::Bug,
+                })?
+        }
     }
 
     pub fn chunk_count_hint(&self) -> usize {