diff --git a/crates/build/re_types_builder/src/codegen/rust/serializer.rs b/crates/build/re_types_builder/src/codegen/rust/serializer.rs
index d5208b9bf543..11d3facc4b8c 100644
--- a/crates/build/re_types_builder/src/codegen/rust/serializer.rs
+++ b/crates/build/re_types_builder/src/codegen/rust/serializer.rs
@@ -585,57 +585,59 @@ fn quote_arrow_field_serializer(
         DataType::Utf8 => {
             // NOTE: We need values for all slots, regardless of what the validity says,
             // hence `unwrap_or_default`.
-            let (quoted_transparent_mapping, quoted_transparent_length) =
-                if inner_is_arrow_transparent {
-                    let inner_obj = inner_obj.as_ref().unwrap();
-                    let is_tuple_struct = is_tuple_struct_from_obj(inner_obj);
-                    let quoted_data_dst = format_ident!(
-                        "{}",
-                        if is_tuple_struct {
-                            "data0"
-                        } else {
-                            inner_obj.fields[0].name.as_str()
-                        }
-                    );
-                    let quoted_member_accessor = if is_tuple_struct {
-                        quote!(0)
+            let (quoted_member_accessor, quoted_transparent_length) = if inner_is_arrow_transparent
+            {
+                let inner_obj = inner_obj.as_ref().unwrap();
+                let is_tuple_struct = is_tuple_struct_from_obj(inner_obj);
+                let quoted_data_dst = format_ident!(
+                    "{}",
+                    if is_tuple_struct {
+                        "data0"
                     } else {
-                        quote!(#quoted_data_dst)
-                    };
-
-                    (
-                        quote! {
-                            .flat_map(|datum| {
-                                datum.#quoted_member_accessor.into_arrow2_buffer()
-                            })
-                        },
-                        quote! {
-                            .map(|datum| {
-                                datum.#quoted_member_accessor.len()
-                            })
-                        },
-                    )
+                        inner_obj.fields[0].name.as_str()
+                    }
+                );
+                let quoted_member_accessor = if is_tuple_struct {
+                    quote!(.0)
                 } else {
-                    (
-                        quote! {
-                            .flat_map(|s| s.into_arrow2_buffer())
-                        },
-                        quote! {
-                            .map(|datum| datum.len())
-                        },
-                    )
+                    quote!(.#quoted_data_dst)
                 };
 
+                (
+                    quoted_member_accessor.clone(),
+                    quote! {
+                        .map(|datum| {
+                            datum #quoted_member_accessor.len()
+                        })
+                    },
+                )
+            } else {
+                (
+                    quote! {},
+                    quote! {
+                        .map(|datum| datum.len())
+                    },
+                )
+            };
+
             let inner_data_and_offsets = if elements_are_nullable {
                 quote! {
                     let offsets = arrow::buffer::OffsetBuffer::<i32>::from_lengths(
                         #data_src.iter().map(|opt| opt.as_ref() #quoted_transparent_length .unwrap_or_default())
                     );
 
+                    // Offsets is always non-empty. The last element is the total length of buffer we need.
+                    // We want this capacity in order to allocate exactly as much memory as we need.
+                    #[allow(clippy::unwrap_used)]
+                    let capacity = offsets.last().copied().unwrap() as usize;
+
+                    let mut buffer_builder = arrow::array::builder::BufferBuilder::<u8>::new(capacity);
                     // NOTE: Flattening to remove the guaranteed layer of nullability: we don't care
                     // about it while building the backing buffer since it's all offsets driven.
-                    let inner_data: arrow::buffer::Buffer =
-                        #data_src.into_iter().flatten() #quoted_transparent_mapping.collect();
+                    for data in #data_src.iter().flatten() {
+                        buffer_builder.append_slice(data #quoted_member_accessor.as_bytes());
+                    }
+                    let inner_data: arrow::buffer::Buffer = buffer_builder.finish();
                 }
             } else {
                 quote! {
@@ -643,8 +645,16 @@ fn quote_arrow_field_serializer(
                         #data_src.iter() #quoted_transparent_length
                     );
 
-                    let inner_data: arrow::buffer::Buffer =
-                        #data_src.into_iter() #quoted_transparent_mapping.collect();
+                    // Offsets is always non-empty. The last element is the total length of buffer we need.
+                    // We want this capacity in order to allocate exactly as much memory as we need.
+                    #[allow(clippy::unwrap_used)]
+                    let capacity = offsets.last().copied().unwrap() as usize;
+
+                    let mut buffer_builder = arrow::array::builder::BufferBuilder::<u8>::new(capacity);
+                    for data in &#data_src {
+                        buffer_builder.append_slice(data #quoted_member_accessor.as_bytes());
+                    }
+                    let inner_data: arrow::buffer::Buffer = buffer_builder.finish();
                 }
             };
 
diff --git a/crates/store/re_types/src/blueprint/datatypes/component_column_selector.rs b/crates/store/re_types/src/blueprint/datatypes/component_column_selector.rs
index 2dde6fbb57c1..15257961b4dd 100644
--- a/crates/store/re_types/src/blueprint/datatypes/component_column_selector.rs
+++ b/crates/store/re_types/src/blueprint/datatypes/component_column_selector.rs
@@ -104,11 +104,15 @@ impl ::re_types_core::Loggable for ComponentColumnSelector {
                                     opt.as_ref().map(|datum| datum.0.len()).unwrap_or_default()
                                 }),
                             );
-                            let inner_data: arrow::buffer::Buffer = entity_path
-                                .into_iter()
-                                .flatten()
-                                .flat_map(|datum| datum.0.into_arrow2_buffer())
-                                .collect();
+                            #[allow(clippy::unwrap_used)]
+                            let capacity = offsets.last().copied().unwrap() as usize;
+                            let mut buffer_builder =
+                                arrow::array::builder::BufferBuilder::<u8>::new(capacity);
+                            for data in entity_path.iter().flatten() {
+                                buffer_builder.append_slice(data.0.as_bytes());
+                            }
+                            let inner_data: arrow::buffer::Buffer = buffer_builder.finish();
+
                             #[allow(unsafe_code, clippy::undocumented_unsafe_blocks)]
                             as_array_ref(unsafe {
                                 StringArray::new_unchecked(
@@ -137,11 +141,14 @@ impl ::re_types_core::Loggable for ComponentColumnSelector {
                                     opt.as_ref().map(|datum| datum.0.len()).unwrap_or_default()
                                 }),
                             );
-                            let inner_data: arrow::buffer::Buffer = component
-                                .into_iter()
-                                .flatten()
-                                .flat_map(|datum| datum.0.into_arrow2_buffer())
-                                .collect();
+                            #[allow(clippy::unwrap_used)]
+                            let capacity = offsets.last().copied().unwrap() as usize;
+                            let mut buffer_builder =
+                                arrow::array::builder::BufferBuilder::<u8>::new(capacity);
+                            for data in component.iter().flatten() {
+                                buffer_builder.append_slice(data.0.as_bytes());
+                            }
+                            let inner_data: arrow::buffer::Buffer = buffer_builder.finish();
 
                             #[allow(unsafe_code, clippy::undocumented_unsafe_blocks)]
                             as_array_ref(unsafe {
diff --git a/crates/store/re_types/src/blueprint/datatypes/selected_columns.rs b/crates/store/re_types/src/blueprint/datatypes/selected_columns.rs
index 43d8bec361a1..db84346e598b 100644
--- a/crates/store/re_types/src/blueprint/datatypes/selected_columns.rs
+++ b/crates/store/re_types/src/blueprint/datatypes/selected_columns.rs
@@ -135,10 +135,15 @@ impl ::re_types_core::Loggable for SelectedColumns {
                                     let offsets = arrow::buffer::OffsetBuffer::<i32>::from_lengths(
                                         time_columns_inner_data.iter().map(|datum| datum.0.len()),
                                     );
-                                    let inner_data: arrow::buffer::Buffer = time_columns_inner_data
-                                        .into_iter()
-                                        .flat_map(|datum| datum.0.into_arrow2_buffer())
-                                        .collect();
+                                    #[allow(clippy::unwrap_used)]
+                                    let capacity = offsets.last().copied().unwrap() as usize;
+                                    let mut buffer_builder =
+                                        arrow::array::builder::BufferBuilder::<u8>::new(capacity);
+                                    for data in &time_columns_inner_data {
+                                        buffer_builder.append_slice(data.0.as_bytes());
+                                    }
+                                    let inner_data: arrow::buffer::Buffer = buffer_builder.finish();
+
                                     #[allow(unsafe_code, clippy::undocumented_unsafe_blocks)]
                                     as_array_ref(unsafe {
                                         StringArray::new_unchecked(
diff --git a/crates/store/re_types/src/blueprint/datatypes/utf8list.rs b/crates/store/re_types/src/blueprint/datatypes/utf8list.rs
index 0e2bf517c123..c8a00d1be0d3 100644
--- a/crates/store/re_types/src/blueprint/datatypes/utf8list.rs
+++ b/crates/store/re_types/src/blueprint/datatypes/utf8list.rs
@@ -75,10 +75,15 @@ impl ::re_types_core::Loggable for Utf8List {
                         let offsets = arrow::buffer::OffsetBuffer::<i32>::from_lengths(
                             data0_inner_data.iter().map(|datum| datum.len()),
                         );
-                        let inner_data: arrow::buffer::Buffer = data0_inner_data
-                            .into_iter()
-                            .flat_map(|s| s.into_arrow2_buffer())
-                            .collect();
+
+                        #[allow(clippy::unwrap_used)]
+                        let capacity = offsets.last().copied().unwrap() as usize;
+                        let mut buffer_builder =
+                            arrow::array::builder::BufferBuilder::<u8>::new(capacity);
+                        for data in &data0_inner_data {
+                            buffer_builder.append_slice(data.as_bytes());
+                        }
+                        let inner_data: arrow::buffer::Buffer = buffer_builder.finish();
 
                         #[allow(unsafe_code, clippy::undocumented_unsafe_blocks)]
                         as_array_ref(unsafe {
diff --git a/crates/store/re_types/src/datatypes/annotation_info.rs b/crates/store/re_types/src/datatypes/annotation_info.rs
index fc5903aecce8..72959487214b 100644
--- a/crates/store/re_types/src/datatypes/annotation_info.rs
+++ b/crates/store/re_types/src/datatypes/annotation_info.rs
@@ -118,11 +118,15 @@ impl ::re_types_core::Loggable for AnnotationInfo {
                                     opt.as_ref().map(|datum| datum.0.len()).unwrap_or_default()
                                 }),
                             );
-                            let inner_data: arrow::buffer::Buffer = label
-                                .into_iter()
-                                .flatten()
-                                .flat_map(|datum| datum.0.into_arrow2_buffer())
-                                .collect();
+                            #[allow(clippy::unwrap_used)]
+                            let capacity = offsets.last().copied().unwrap() as usize;
+                            let mut buffer_builder =
+                                arrow::array::builder::BufferBuilder::<u8>::new(capacity);
+                            for data in label.iter().flatten() {
+                                buffer_builder.append_slice(data.0.as_bytes());
+                            }
+                            let inner_data: arrow::buffer::Buffer = buffer_builder.finish();
+
                             #[allow(unsafe_code, clippy::undocumented_unsafe_blocks)]
                             as_array_ref(unsafe {
                                 StringArray::new_unchecked(offsets, inner_data, label_validity)
diff --git a/crates/store/re_types/src/datatypes/tensor_data.rs b/crates/store/re_types/src/datatypes/tensor_data.rs
index 315248747bee..0c28d9ff6285 100644
--- a/crates/store/re_types/src/datatypes/tensor_data.rs
+++ b/crates/store/re_types/src/datatypes/tensor_data.rs
@@ -193,10 +193,14 @@ impl ::re_types_core::Loggable for TensorData {
                                     let offsets = arrow::buffer::OffsetBuffer::<i32>::from_lengths(
                                         names_inner_data.iter().map(|datum| datum.len()),
                                     );
-                                    let inner_data: arrow::buffer::Buffer = names_inner_data
-                                        .into_iter()
-                                        .flat_map(|s| s.into_arrow2_buffer())
-                                        .collect();
+                                    #[allow(clippy::unwrap_used)]
+                                    let capacity = offsets.last().copied().unwrap() as usize;
+                                    let mut buffer_builder =
+                                        arrow::array::builder::BufferBuilder::<u8>::new(capacity);
+                                    for data in &names_inner_data {
+                                        buffer_builder.append_slice(data.as_bytes());
+                                    }
+                                    let inner_data: arrow::buffer::Buffer = buffer_builder.finish();
                                     #[allow(unsafe_code, clippy::undocumented_unsafe_blocks)]
                                     as_array_ref(unsafe {
                                         StringArray::new_unchecked(
diff --git a/crates/store/re_types/src/datatypes/utf8pair.rs b/crates/store/re_types/src/datatypes/utf8pair.rs
index 928fb06e5fe6..38d450665af0 100644
--- a/crates/store/re_types/src/datatypes/utf8pair.rs
+++ b/crates/store/re_types/src/datatypes/utf8pair.rs
@@ -88,11 +88,15 @@ impl ::re_types_core::Loggable for Utf8Pair {
                                     opt.as_ref().map(|datum| datum.0.len()).unwrap_or_default()
                                 }),
                             );
-                            let inner_data: arrow::buffer::Buffer = first
-                                .into_iter()
-                                .flatten()
-                                .flat_map(|datum| datum.0.into_arrow2_buffer())
-                                .collect();
+                            #[allow(clippy::unwrap_used)]
+                            let capacity = offsets.last().copied().unwrap() as usize;
+                            let mut buffer_builder =
+                                arrow::array::builder::BufferBuilder::<u8>::new(capacity);
+                            for data in first.iter().flatten() {
+                                buffer_builder.append_slice(data.0.as_bytes());
+                            }
+                            let inner_data: arrow::buffer::Buffer = buffer_builder.finish();
+
                             #[allow(unsafe_code, clippy::undocumented_unsafe_blocks)]
                             as_array_ref(unsafe {
                                 StringArray::new_unchecked(offsets, inner_data, first_validity)
@@ -117,11 +121,16 @@ impl ::re_types_core::Loggable for Utf8Pair {
                                     opt.as_ref().map(|datum| datum.0.len()).unwrap_or_default()
                                 }),
                             );
-                            let inner_data: arrow::buffer::Buffer = second
-                                .into_iter()
-                                .flatten()
-                                .flat_map(|datum| datum.0.into_arrow2_buffer())
-                                .collect();
+
+                            #[allow(clippy::unwrap_used)]
+                            let capacity = offsets.last().copied().unwrap() as usize;
+                            let mut buffer_builder =
+                                arrow::array::builder::BufferBuilder::<u8>::new(capacity);
+                            for data in second.iter().flatten() {
+                                buffer_builder.append_slice(data.0.as_bytes());
+                            }
+                            let inner_data: arrow::buffer::Buffer = buffer_builder.finish();
+
                             #[allow(unsafe_code, clippy::undocumented_unsafe_blocks)]
                             as_array_ref(unsafe {
                                 StringArray::new_unchecked(offsets, inner_data, second_validity)
diff --git a/crates/store/re_types/src/testing/components/affix_fuzzer10.rs b/crates/store/re_types/src/testing/components/affix_fuzzer10.rs
index 204f429d70fd..bbca1295e226 100644
--- a/crates/store/re_types/src/testing/components/affix_fuzzer10.rs
+++ b/crates/store/re_types/src/testing/components/affix_fuzzer10.rs
@@ -67,11 +67,14 @@ impl ::re_types_core::Loggable for AffixFuzzer10 {
                         .iter()
                         .map(|opt| opt.as_ref().map(|datum| datum.len()).unwrap_or_default()),
                 );
-                let inner_data: arrow::buffer::Buffer = data0
-                    .into_iter()
-                    .flatten()
-                    .flat_map(|s| s.into_arrow2_buffer())
-                    .collect();
+
+                #[allow(clippy::unwrap_used)]
+                let capacity = offsets.last().copied().unwrap() as usize;
+                let mut buffer_builder = arrow::array::builder::BufferBuilder::<u8>::new(capacity);
+                for data in data0.iter().flatten() {
+                    buffer_builder.append_slice(data.as_bytes());
+                }
+                let inner_data: arrow::buffer::Buffer = buffer_builder.finish();
 
                 #[allow(unsafe_code, clippy::undocumented_unsafe_blocks)]
                 as_array_ref(unsafe {
diff --git a/crates/store/re_types/src/testing/components/affix_fuzzer12.rs b/crates/store/re_types/src/testing/components/affix_fuzzer12.rs
index fbc078b5beb8..b4676ed1aaf7 100644
--- a/crates/store/re_types/src/testing/components/affix_fuzzer12.rs
+++ b/crates/store/re_types/src/testing/components/affix_fuzzer12.rs
@@ -80,10 +80,15 @@ impl ::re_types_core::Loggable for AffixFuzzer12 {
                         let offsets = arrow::buffer::OffsetBuffer::<i32>::from_lengths(
                             data0_inner_data.iter().map(|datum| datum.len()),
                         );
-                        let inner_data: arrow::buffer::Buffer = data0_inner_data
-                            .into_iter()
-                            .flat_map(|s| s.into_arrow2_buffer())
-                            .collect();
+
+                        #[allow(clippy::unwrap_used)]
+                        let capacity = offsets.last().copied().unwrap() as usize;
+                        let mut buffer_builder =
+                            arrow::array::builder::BufferBuilder::<u8>::new(capacity);
+                        for data in &data0_inner_data {
+                            buffer_builder.append_slice(data.as_bytes());
+                        }
+                        let inner_data: arrow::buffer::Buffer = buffer_builder.finish();
 
                         #[allow(unsafe_code, clippy::undocumented_unsafe_blocks)]
                         as_array_ref(unsafe {
diff --git a/crates/store/re_types/src/testing/components/affix_fuzzer13.rs b/crates/store/re_types/src/testing/components/affix_fuzzer13.rs
index 9342d264d038..8937fe3bb284 100644
--- a/crates/store/re_types/src/testing/components/affix_fuzzer13.rs
+++ b/crates/store/re_types/src/testing/components/affix_fuzzer13.rs
@@ -80,10 +80,15 @@ impl ::re_types_core::Loggable for AffixFuzzer13 {
                         let offsets = arrow::buffer::OffsetBuffer::<i32>::from_lengths(
                             data0_inner_data.iter().map(|datum| datum.len()),
                         );
-                        let inner_data: arrow::buffer::Buffer = data0_inner_data
-                            .into_iter()
-                            .flat_map(|s| s.into_arrow2_buffer())
-                            .collect();
+
+                        #[allow(clippy::unwrap_used)]
+                        let capacity = offsets.last().copied().unwrap() as usize;
+                        let mut buffer_builder =
+                            arrow::array::builder::BufferBuilder::<u8>::new(capacity);
+                        for data in &data0_inner_data {
+                            buffer_builder.append_slice(data.as_bytes());
+                        }
+                        let inner_data: arrow::buffer::Buffer = buffer_builder.finish();
 
                         #[allow(unsafe_code, clippy::undocumented_unsafe_blocks)]
                         as_array_ref(unsafe {
diff --git a/crates/store/re_types/src/testing/components/affix_fuzzer9.rs b/crates/store/re_types/src/testing/components/affix_fuzzer9.rs
index 59e32c0d2904..68c5ec93327a 100644
--- a/crates/store/re_types/src/testing/components/affix_fuzzer9.rs
+++ b/crates/store/re_types/src/testing/components/affix_fuzzer9.rs
@@ -67,11 +67,14 @@ impl ::re_types_core::Loggable for AffixFuzzer9 {
                         .iter()
                         .map(|opt| opt.as_ref().map(|datum| datum.len()).unwrap_or_default()),
                 );
-                let inner_data: arrow::buffer::Buffer = data0
-                    .into_iter()
-                    .flatten()
-                    .flat_map(|s| s.into_arrow2_buffer())
-                    .collect();
+
+                #[allow(clippy::unwrap_used)]
+                let capacity = offsets.last().copied().unwrap() as usize;
+                let mut buffer_builder = arrow::array::builder::BufferBuilder::<u8>::new(capacity);
+                for data in data0.iter().flatten() {
+                    buffer_builder.append_slice(data.as_bytes());
+                }
+                let inner_data: arrow::buffer::Buffer = buffer_builder.finish();
 
                 #[allow(unsafe_code, clippy::undocumented_unsafe_blocks)]
                 as_array_ref(unsafe {
diff --git a/crates/store/re_types/src/testing/datatypes/affix_fuzzer1.rs b/crates/store/re_types/src/testing/datatypes/affix_fuzzer1.rs
index ea42e58924af..13e6f4f041ae 100644
--- a/crates/store/re_types/src/testing/datatypes/affix_fuzzer1.rs
+++ b/crates/store/re_types/src/testing/datatypes/affix_fuzzer1.rs
@@ -188,11 +188,16 @@ impl ::re_types_core::Loggable for AffixFuzzer1 {
                                     opt.as_ref().map(|datum| datum.len()).unwrap_or_default()
                                 }),
                             );
-                            let inner_data: arrow::buffer::Buffer = single_string_required
-                                .into_iter()
-                                .flatten()
-                                .flat_map(|s| s.into_arrow2_buffer())
-                                .collect();
+
+                            #[allow(clippy::unwrap_used)]
+                            let capacity = offsets.last().copied().unwrap() as usize;
+                            let mut buffer_builder =
+                                arrow::array::builder::BufferBuilder::<u8>::new(capacity);
+                            for data in single_string_required.iter().flatten() {
+                                buffer_builder.append_slice(data.as_bytes());
+                            }
+                            let inner_data: arrow::buffer::Buffer = buffer_builder.finish();
+
                             #[allow(unsafe_code, clippy::undocumented_unsafe_blocks)]
                             as_array_ref(unsafe {
                                 StringArray::new_unchecked(
@@ -224,11 +229,16 @@ impl ::re_types_core::Loggable for AffixFuzzer1 {
                                     opt.as_ref().map(|datum| datum.len()).unwrap_or_default()
                                 }),
                             );
-                            let inner_data: arrow::buffer::Buffer = single_string_optional
-                                .into_iter()
-                                .flatten()
-                                .flat_map(|s| s.into_arrow2_buffer())
-                                .collect();
+
+                            #[allow(clippy::unwrap_used)]
+                            let capacity = offsets.last().copied().unwrap() as usize;
+                            let mut buffer_builder =
+                                arrow::array::builder::BufferBuilder::<u8>::new(capacity);
+                            for data in single_string_optional.iter().flatten() {
+                                buffer_builder.append_slice(data.as_bytes());
+                            }
+                            let inner_data: arrow::buffer::Buffer = buffer_builder.finish();
+
                             #[allow(unsafe_code, clippy::undocumented_unsafe_blocks)]
                             as_array_ref(unsafe {
                                 StringArray::new_unchecked(
@@ -319,11 +329,15 @@ impl ::re_types_core::Loggable for AffixFuzzer1 {
                                             .iter()
                                             .map(|datum| datum.len()),
                                     );
-                                    let inner_data: arrow::buffer::Buffer =
-                                        many_strings_required_inner_data
-                                            .into_iter()
-                                            .flat_map(|s| s.into_arrow2_buffer())
-                                            .collect();
+                                    #[allow(clippy::unwrap_used)]
+                                    let capacity = offsets.last().copied().unwrap() as usize;
+                                    let mut buffer_builder =
+                                        arrow::array::builder::BufferBuilder::<u8>::new(capacity);
+                                    for data in &many_strings_required_inner_data {
+                                        buffer_builder.append_slice(data.as_bytes());
+                                    }
+                                    let inner_data: arrow::buffer::Buffer = buffer_builder.finish();
+
                                     #[allow(unsafe_code, clippy::undocumented_unsafe_blocks)]
                                     as_array_ref(unsafe {
                                         StringArray::new_unchecked(
@@ -375,11 +389,15 @@ impl ::re_types_core::Loggable for AffixFuzzer1 {
                                             .iter()
                                             .map(|datum| datum.len()),
                                     );
-                                    let inner_data: arrow::buffer::Buffer =
-                                        many_strings_optional_inner_data
-                                            .into_iter()
-                                            .flat_map(|s| s.into_arrow2_buffer())
-                                            .collect();
+                                    #[allow(clippy::unwrap_used)]
+                                    let capacity = offsets.last().copied().unwrap() as usize;
+                                    let mut buffer_builder =
+                                        arrow::array::builder::BufferBuilder::<u8>::new(capacity);
+                                    for data in &many_strings_optional_inner_data {
+                                        buffer_builder.append_slice(data.as_bytes());
+                                    }
+                                    let inner_data: arrow::buffer::Buffer = buffer_builder.finish();
+
                                     #[allow(unsafe_code, clippy::undocumented_unsafe_blocks)]
                                     as_array_ref(unsafe {
                                         StringArray::new_unchecked(
diff --git a/crates/store/re_types/src/testing/datatypes/affix_fuzzer20.rs b/crates/store/re_types/src/testing/datatypes/affix_fuzzer20.rs
index e7b0af03f603..dd0c35d1ab74 100644
--- a/crates/store/re_types/src/testing/datatypes/affix_fuzzer20.rs
+++ b/crates/store/re_types/src/testing/datatypes/affix_fuzzer20.rs
@@ -121,11 +121,15 @@ impl ::re_types_core::Loggable for AffixFuzzer20 {
                                     opt.as_ref().map(|datum| datum.0.len()).unwrap_or_default()
                                 }),
                             );
-                            let inner_data: arrow::buffer::Buffer = s
-                                .into_iter()
-                                .flatten()
-                                .flat_map(|datum| datum.0.into_arrow2_buffer())
-                                .collect();
+                            #[allow(clippy::unwrap_used)]
+                            let capacity = offsets.last().copied().unwrap() as usize;
+                            let mut buffer_builder =
+                                arrow::array::builder::BufferBuilder::<u8>::new(capacity);
+                            for data in s.iter().flatten() {
+                                buffer_builder.append_slice(data.0.as_bytes());
+                            }
+                            let inner_data: arrow::buffer::Buffer = buffer_builder.finish();
+
                             #[allow(unsafe_code, clippy::undocumented_unsafe_blocks)]
                             as_array_ref(unsafe {
                                 StringArray::new_unchecked(offsets, inner_data, s_validity)
diff --git a/crates/store/re_types/src/testing/datatypes/string_component.rs b/crates/store/re_types/src/testing/datatypes/string_component.rs
index fc7b9f1cdb06..33519adf8643 100644
--- a/crates/store/re_types/src/testing/datatypes/string_component.rs
+++ b/crates/store/re_types/src/testing/datatypes/string_component.rs
@@ -61,11 +61,14 @@ impl ::re_types_core::Loggable for StringComponent {
                         .iter()
                         .map(|opt| opt.as_ref().map(|datum| datum.len()).unwrap_or_default()),
                 );
-                let inner_data: arrow::buffer::Buffer = data0
-                    .into_iter()
-                    .flatten()
-                    .flat_map(|s| s.into_arrow2_buffer())
-                    .collect();
+
+                #[allow(clippy::unwrap_used)]
+                let capacity = offsets.last().copied().unwrap() as usize;
+                let mut buffer_builder = arrow::array::builder::BufferBuilder::<u8>::new(capacity);
+                for data in data0.iter().flatten() {
+                    buffer_builder.append_slice(data.as_bytes());
+                }
+                let inner_data: arrow::buffer::Buffer = buffer_builder.finish();
 
                 #[allow(unsafe_code, clippy::undocumented_unsafe_blocks)]
                 as_array_ref(unsafe {
diff --git a/crates/store/re_types_core/src/arrow_string.rs b/crates/store/re_types_core/src/arrow_string.rs
index 492981a1ea3f..d4db7b085247 100644
--- a/crates/store/re_types_core/src/arrow_string.rs
+++ b/crates/store/re_types_core/src/arrow_string.rs
@@ -62,14 +62,15 @@ impl ArrowString {
         std::str::from_utf8(self.0.as_ref()).unwrap_or("INVALID UTF-8")
     }
 
+    /// The raw UTF8 bytes.
     #[inline]
-    pub fn into_arrow_buffer(self) -> arrow::buffer::Buffer {
-        self.0
+    pub fn as_bytes(&self) -> &[u8] {
+        self.0.as_slice()
     }
 
     #[inline]
-    pub fn into_arrow2_buffer(self) -> arrow2::buffer::Buffer<u8> {
-        self.0.into()
+    pub fn into_arrow_buffer(self) -> arrow::buffer::Buffer {
+        self.0
     }
 }
 
diff --git a/crates/store/re_types_core/src/datatypes/entity_path.rs b/crates/store/re_types_core/src/datatypes/entity_path.rs
index 6d0dcb557526..82500a6eb71f 100644
--- a/crates/store/re_types_core/src/datatypes/entity_path.rs
+++ b/crates/store/re_types_core/src/datatypes/entity_path.rs
@@ -62,11 +62,14 @@ impl crate::Loggable for EntityPath {
                         .iter()
                         .map(|opt| opt.as_ref().map(|datum| datum.len()).unwrap_or_default()),
                 );
-                let inner_data: arrow::buffer::Buffer = data0
-                    .into_iter()
-                    .flatten()
-                    .flat_map(|s| s.into_arrow2_buffer())
-                    .collect();
+
+                #[allow(clippy::unwrap_used)]
+                let capacity = offsets.last().copied().unwrap() as usize;
+                let mut buffer_builder = arrow::array::builder::BufferBuilder::<u8>::new(capacity);
+                for data in data0.iter().flatten() {
+                    buffer_builder.append_slice(data.as_bytes());
+                }
+                let inner_data: arrow::buffer::Buffer = buffer_builder.finish();
 
                 #[allow(unsafe_code, clippy::undocumented_unsafe_blocks)]
                 as_array_ref(unsafe {
diff --git a/crates/store/re_types_core/src/datatypes/utf8.rs b/crates/store/re_types_core/src/datatypes/utf8.rs
index 8b5a927b46fb..a55595ac30e0 100644
--- a/crates/store/re_types_core/src/datatypes/utf8.rs
+++ b/crates/store/re_types_core/src/datatypes/utf8.rs
@@ -62,11 +62,14 @@ impl crate::Loggable for Utf8 {
                         .iter()
                         .map(|opt| opt.as_ref().map(|datum| datum.len()).unwrap_or_default()),
                 );
-                let inner_data: arrow::buffer::Buffer = data0
-                    .into_iter()
-                    .flatten()
-                    .flat_map(|s| s.into_arrow2_buffer())
-                    .collect();
+
+                #[allow(clippy::unwrap_used)]
+                let capacity = offsets.last().copied().unwrap() as usize;
+                let mut buffer_builder = arrow::array::builder::BufferBuilder::<u8>::new(capacity);
+                for data in data0.iter().flatten() {
+                    buffer_builder.append_slice(data.as_bytes());
+                }
+                let inner_data: arrow::buffer::Buffer = buffer_builder.finish();
 
                 #[allow(unsafe_code, clippy::undocumented_unsafe_blocks)]
                 as_array_ref(unsafe {
diff --git a/crates/store/re_types_core/src/datatypes/visible_time_range.rs b/crates/store/re_types_core/src/datatypes/visible_time_range.rs
index c9855edf005e..d666d25e3a63 100644
--- a/crates/store/re_types_core/src/datatypes/visible_time_range.rs
+++ b/crates/store/re_types_core/src/datatypes/visible_time_range.rs
@@ -104,11 +104,15 @@ impl crate::Loggable for VisibleTimeRange {
                                     opt.as_ref().map(|datum| datum.0.len()).unwrap_or_default()
                                 }),
                             );
-                            let inner_data: arrow::buffer::Buffer = timeline
-                                .into_iter()
-                                .flatten()
-                                .flat_map(|datum| datum.0.into_arrow2_buffer())
-                                .collect();
+                            #[allow(clippy::unwrap_used)]
+                            let capacity = offsets.last().copied().unwrap() as usize;
+                            let mut buffer_builder =
+                                arrow::array::builder::BufferBuilder::<u8>::new(capacity);
+                            for data in timeline.iter().flatten() {
+                                buffer_builder.append_slice(data.0.as_bytes());
+                            }
+                            let inner_data: arrow::buffer::Buffer = buffer_builder.finish();
+
                             #[allow(unsafe_code, clippy::undocumented_unsafe_blocks)]
                             as_array_ref(unsafe {
                                 StringArray::new_unchecked(offsets, inner_data, timeline_validity)