diff --git a/src/session/builder/impl_options.rs b/src/session/builder/impl_options.rs
index aad1873..85ed535 100644
--- a/src/session/builder/impl_options.rs
+++ b/src/session/builder/impl_options.rs
@@ -1,6 +1,4 @@
-#[cfg(not(windows))]
-use std::ffi::CString;
-use std::{path::Path, rc::Rc, sync::Arc};
+use std::{borrow::Cow, path::Path, rc::Rc, sync::Arc};
 
 use super::SessionBuilder;
 use crate::{
@@ -8,7 +6,7 @@ use crate::{
 	execution_providers::{apply_execution_providers, ExecutionProviderDispatch},
 	ortsys,
 	util::path_to_os_char,
-	MemoryInfo, OperatorDomain
+	DynValue, MemoryInfo, OperatorDomain
 };
 
 impl SessionBuilder {
@@ -79,22 +77,16 @@ impl SessionBuilder {
 	/// newly optimized model to the given path (for 'offline' graph optimization).
 	///
 	/// Note that the file will only be created after the model is committed.
-	pub fn with_optimized_model_path<S: AsRef<str>>(self, path: S) -> Result<Self> {
-		#[cfg(windows)]
-		let path = path.as_ref().encode_utf16().chain([0]).collect::<Vec<_>>();
-		#[cfg(not(windows))]
-		let path = CString::new(path.as_ref())?;
+	pub fn with_optimized_model_path<S: AsRef<Path>>(self, path: S) -> Result<Self> {
+		let path = crate::util::path_to_os_char(path);
 		ortsys![unsafe SetOptimizedModelFilePath(self.session_options_ptr.as_ptr(), path.as_ptr())?];
 		Ok(self)
 	}
 
 	/// Enables profiling. Profile information will be writen to `profiling_file` after profiling completes.
 	/// See [`Session::end_profiling`].
-	pub fn with_profiling<S: AsRef<str>>(self, profiling_file: S) -> Result<Self> {
-		#[cfg(windows)]
-		let profiling_file = profiling_file.as_ref().encode_utf16().chain([0]).collect::<Vec<_>>();
-		#[cfg(not(windows))]
-		let profiling_file = CString::new(profiling_file.as_ref())?;
+	pub fn with_profiling<S: AsRef<Path>>(self, profiling_file: S) -> Result<Self> {
+		let profiling_file = crate::util::path_to_os_char(profiling_file);
 		ortsys![unsafe EnableProfiling(self.session_options_ptr.as_ptr(), profiling_file.as_ptr())?];
 		Ok(self)
 	}
@@ -136,6 +128,35 @@ impl SessionBuilder {
 		self.operator_domains.push(domain);
 		Ok(self)
 	}
+
+	/// Enables/disables deterministic computation.
+	///
+	/// The default (non-deterministic) kernels will typically use faster algorithms that may introduce slight variance.
+	/// Enabling deterministic compute will output reproducible results, but may come at a performance penalty.
+	pub fn with_deterministic_compute(self, enable: bool) -> Result<Self> {
+		ortsys![unsafe SetDeterministicCompute(self.session_options_ptr.as_ptr(), enable)?];
+		Ok(self)
+	}
+
+	pub fn with_external_initializer(mut self, name: impl AsRef<str>, value: DynValue) -> Result<Self> {
+		let name = name.as_ref();
+		let value = Rc::new(value);
+		ortsys![unsafe AddExternalInitializers(self.session_options_ptr.as_ptr(), &name.as_ptr().cast::<i8>(), &value.ptr().cast_const(), 1)?];
+		self.external_initializers.push(value);
+		Ok(self)
+	}
+
+	pub fn with_external_initializer_file(mut self, file_name: impl AsRef<Path>, buffer: Cow<'static, [u8]>) -> Result<Self> {
+		// We need to hold onto `buffer` until the session is actually committed. This means `buffer` must outlive 'self (if
+		// SessionBuilder were to have a lifetime). Adding a lifetime to SessionBuilder would be breaking, so right now we
+		// either accept a &'static [u8] or Vec<u8> via Cow<'_, [u8]>, which still allows users to use include_bytes!.
+
+		let file_name = crate::util::path_to_os_char(file_name);
+		let sizes = [buffer.len() as ort_sys::size_t];
+		ortsys![unsafe AddExternalInitializersFromMemory(self.session_options_ptr.as_ptr(), &file_name.as_ptr(), &buffer.as_ptr().cast::<i8>().cast_mut(), sizes.as_ptr(), 1)?];
+		self.external_initializer_buffers.push(buffer);
+		Ok(self)
+	}
 }
 
 /// ONNX Runtime provides various graph optimizations to improve performance. Graph optimizations are essentially
diff --git a/src/session/builder/mod.rs b/src/session/builder/mod.rs
index 2a4e5c1..3f6c051 100644
--- a/src/session/builder/mod.rs
+++ b/src/session/builder/mod.rs
@@ -1,4 +1,5 @@
 use std::{
+	borrow::Cow,
 	ffi::CString,
 	ptr::{self, NonNull},
 	rc::Rc,
@@ -9,7 +10,7 @@ use crate::{
 	error::{assert_non_null_pointer, status_to_result, Result},
 	memory::MemoryInfo,
 	operator::OperatorDomain,
-	ortsys
+	ortsys, DynValue
 };
 
 mod impl_commit;
@@ -36,7 +37,9 @@ pub use self::impl_options::GraphOptimizationLevel;
 pub struct SessionBuilder {
 	pub(crate) session_options_ptr: NonNull<ort_sys::OrtSessionOptions>,
 	memory_info: Option<Rc<MemoryInfo>>,
-	operator_domains: Vec<Arc<OperatorDomain>>
+	operator_domains: Vec<Arc<OperatorDomain>>,
+	external_initializers: Vec<Rc<DynValue>>,
+	external_initializer_buffers: Vec<Cow<'static, [u8]>>
 }
 
 impl Clone for SessionBuilder {
@@ -48,7 +51,9 @@ impl Clone for SessionBuilder {
 		Self {
 			session_options_ptr: unsafe { NonNull::new_unchecked(session_options_ptr) },
 			memory_info: self.memory_info.clone(),
-			operator_domains: self.operator_domains.clone()
+			operator_domains: self.operator_domains.clone(),
+			external_initializers: self.external_initializers.clone(),
+			external_initializer_buffers: self.external_initializer_buffers.clone()
 		}
 	}
 }
@@ -79,7 +84,9 @@ impl SessionBuilder {
 		Ok(Self {
 			session_options_ptr: unsafe { NonNull::new_unchecked(session_options_ptr) },
 			memory_info: None,
-			operator_domains: Vec::new()
+			operator_domains: Vec::new(),
+			external_initializers: Vec::new(),
+			external_initializer_buffers: Vec::new()
 		})
 	}