diff --git a/scarb/src/resolver/algorithm/mod.rs b/scarb/src/resolver/algorithm/mod.rs
new file mode 100644
index 000000000..0156e3ba2
--- /dev/null
+++ b/scarb/src/resolver/algorithm/mod.rs
@@ -0,0 +1,12 @@
+use crate::core::lockfile::Lockfile;
+use crate::core::registry::Registry;
+use crate::core::{Resolve, Summary};
+
+#[tracing::instrument(level = "trace", skip_all)]
+pub async fn resolve(
+    _summaries: &[Summary],
+    _registry: &dyn Registry,
+    _lockfile: Lockfile,
+) -> anyhow::Result<Resolve> {
+    todo!("implement")
+}
diff --git a/scarb/src/resolver/mod.rs b/scarb/src/resolver/mod.rs
index f399b569e..111105890 100644
--- a/scarb/src/resolver/mod.rs
+++ b/scarb/src/resolver/mod.rs
@@ -1,17 +1,13 @@
-use std::collections::HashMap;
-
-use anyhow::{bail, Result};
-use indoc::{formatdoc, indoc};
-use petgraph::graphmap::DiGraphMap;
-use std::collections::HashSet;
+use anyhow::Result;
+use std::env;
 
 use crate::core::lockfile::Lockfile;
 use crate::core::registry::Registry;
-use crate::core::resolver::{DependencyEdge, Resolve};
-use crate::core::{
-    DepKind, DependencyFilter, DependencyVersionReq, ManifestDependency, PackageId, Summary,
-    TargetKind,
-};
+use crate::core::resolver::Resolve;
+use crate::core::Summary;
+
+mod algorithm;
+mod primitive;
 
 /// Builds the list of all packages required to build the first argument.
 ///
@@ -38,163 +34,15 @@ pub async fn resolve(
     registry: &dyn Registry,
     lockfile: Lockfile,
 ) -> Result<Resolve> {
-    // TODO(#2): This is very bad, use PubGrub here.
-    let mut graph = DiGraphMap::<PackageId, DependencyEdge>::new();
-
-    let main_packages = summaries
-        .iter()
-        .map(|sum| sum.package_id)
-        .collect::<HashSet<PackageId>>();
-    let mut packages: HashMap<_, _> = HashMap::from_iter(
-        summaries
-            .iter()
-            .map(|s| (s.package_id.name.clone(), s.package_id)),
-    );
-
-    let mut summaries: HashMap<_, _> = summaries
-        .iter()
-        .map(|s| (s.package_id, s.clone()))
-        .collect();
-
-    let mut queue: Vec<PackageId> = summaries.keys().copied().collect();
-    while !queue.is_empty() {
-        let mut next_queue = Vec::new();
-
-        for package_id in queue {
-            graph.add_node(package_id);
-
-            let summary = summaries[&package_id].clone();
-            let dep_filter =
-                DependencyFilter::propagation(main_packages.contains(&summary.package_id));
-            for dep in summary.filtered_full_dependencies(dep_filter) {
-                let dep = rewrite_dependency_source_id(registry, &package_id, dep).await?;
-
-                let locked_package_id = lockfile.packages_matching(dep.clone());
-                let dep = if let Some(locked_package_id) = locked_package_id {
-                    rewrite_locked_dependency(dep.clone(), locked_package_id?)
-                } else {
-                    dep
-                };
-
-                let results = registry.query(&dep).await?;
-
-                let Some(dep_summary) = results.first() else {
-                    bail!("cannot find package {}", dep.name)
-                };
-
-                let dep_target_kind: Option<TargetKind> = match dep.kind.clone() {
-                    DepKind::Normal => None,
-                    DepKind::Target(target_kind) => Some(target_kind),
-                };
-                let dep = dep_summary.package_id;
-
-                if let Some(existing) = packages.get(dep.name.as_ref()) {
-                    if existing.source_id != dep.source_id {
-                        bail!(
-                            indoc! {"
-                            found dependencies on the same package `{}` coming from incompatible \
-                            sources:
-                            source 1: {}
-                            source 2: {}
-                            "},
-                            dep.name,
-                            existing.source_id,
-                            dep.source_id
-                        );
-                    }
-                }
-
-                let weight = graph
-                    .edge_weight(package_id, dep)
-                    .cloned()
-                    .unwrap_or_default();
-                let weight = weight.extend(dep_target_kind);
-                graph.add_edge(package_id, dep, weight);
-                summaries.insert(dep, dep_summary.clone());
-
-                if packages.contains_key(dep.name.as_ref()) {
-                    continue;
-                }
-
-                packages.insert(dep.name.clone(), dep);
-                next_queue.push(dep);
-            }
-        }
-
-        queue = next_queue;
-    }
-
-    // Detect incompatibilities and bail in case ones are found.
-    let mut incompatibilities = Vec::new();
-    for from_package in graph.nodes() {
-        let dep_filter = DependencyFilter::propagation(main_packages.contains(&from_package));
-        for manifest_dependency in summaries[&from_package].filtered_full_dependencies(dep_filter) {
-            let to_package = packages[&manifest_dependency.name];
-            if !manifest_dependency.matches_package_id(to_package) {
-                let message = format!(
-                    "- {from_package} cannot use {to_package}, because {} requires {} {}",
-                    from_package.name, to_package.name, manifest_dependency.version_req
-                );
-                incompatibilities.push(message);
-            }
-        }
-    }
-
-    if !incompatibilities.is_empty() {
-        incompatibilities.sort();
-        let incompatibilities = incompatibilities.join("\n");
-        bail!(formatdoc! {"
-            Version solving failed:
-            {incompatibilities}
-
-            Scarb does not have real version solving algorithm yet.
-            Perhaps in the future this conflict could be resolved, but currently,
-            please upgrade your dependencies to use latest versions of their dependencies.
-        "});
+    let algo_primitive = env::var("SCARB_UNSTABLE_PRIMITIVE_RESOLVER")
+        .ok()
+        .map(|var| var.as_str() == "true")
+        .unwrap_or(true);
+    if algo_primitive {
+        primitive::resolve(summaries, registry, lockfile).await
+    } else {
+        algorithm::resolve(summaries, registry, lockfile).await
     }
-
-    let resolve = Resolve { graph, summaries };
-    resolve.check_checksums(&lockfile)?;
-    Ok(resolve)
-}
-
-fn rewrite_locked_dependency(
-    dependency: ManifestDependency,
-    locked_package_id: PackageId,
-) -> ManifestDependency {
-    ManifestDependency::builder()
-        .kind(dependency.kind.clone())
-        .name(dependency.name.clone())
-        .source_id(locked_package_id.source_id)
-        .version_req(DependencyVersionReq::Locked {
-            exact: locked_package_id.version.clone(),
-            req: dependency.version_req.clone().into(),
-        })
-        .build()
-}
-
-async fn rewrite_dependency_source_id(
-    registry: &dyn Registry,
-    package_id: &PackageId,
-    dependency: &ManifestDependency,
-) -> Result<ManifestDependency> {
-    // Rewrite path dependencies for git sources.
-    if package_id.source_id.is_git() && dependency.source_id.is_path() {
-        let rewritten_dep = ManifestDependency::builder()
-            .kind(dependency.kind.clone())
-            .name(dependency.name.clone())
-            .source_id(package_id.source_id)
-            .version_req(dependency.version_req.clone())
-            .build();
-        // Check if this dependency can be queried from git source.
-        // E.g. packages below other package's manifest will not be accessible.
-        if !registry.query(&rewritten_dep).await?.is_empty() {
-            // If it is, return rewritten dependency.
-            return Ok(rewritten_dep);
-        }
-    };
-
-    Ok(dependency.clone())
 }
 
 #[cfg(test)]
diff --git a/scarb/src/resolver/primitive.rs b/scarb/src/resolver/primitive.rs
new file mode 100644
index 000000000..6e77327ba
--- /dev/null
+++ b/scarb/src/resolver/primitive.rs
@@ -0,0 +1,176 @@
+use crate::core::lockfile::Lockfile;
+use crate::core::registry::Registry;
+use crate::core::resolver::DependencyEdge;
+use crate::core::{
+    DepKind, DependencyFilter, DependencyVersionReq, ManifestDependency, PackageId, Resolve,
+    Summary, TargetKind,
+};
+use anyhow::bail;
+use indoc::{formatdoc, indoc};
+use petgraph::graphmap::DiGraphMap;
+use std::collections::{HashMap, HashSet};
+
+#[tracing::instrument(level = "trace", skip_all)]
+pub async fn resolve(
+    summaries: &[Summary],
+    registry: &dyn Registry,
+    lockfile: Lockfile,
+) -> anyhow::Result<Resolve> {
+    // TODO(#2): This is very bad, use PubGrub here.
+    let mut graph = DiGraphMap::<PackageId, DependencyEdge>::new();
+
+    let main_packages = summaries
+        .iter()
+        .map(|sum| sum.package_id)
+        .collect::<HashSet<PackageId>>();
+    let mut packages: HashMap<_, _> = HashMap::from_iter(
+        summaries
+            .iter()
+            .map(|s| (s.package_id.name.clone(), s.package_id)),
+    );
+
+    let mut summaries: HashMap<_, _> = summaries
+        .iter()
+        .map(|s| (s.package_id, s.clone()))
+        .collect();
+
+    let mut queue: Vec<PackageId> = summaries.keys().copied().collect();
+    while !queue.is_empty() {
+        let mut next_queue = Vec::new();
+
+        for package_id in queue {
+            graph.add_node(package_id);
+
+            let summary = summaries[&package_id].clone();
+            let dep_filter =
+                DependencyFilter::propagation(main_packages.contains(&summary.package_id));
+            for dep in summary.filtered_full_dependencies(dep_filter) {
+                let dep = rewrite_dependency_source_id(registry, &package_id, dep).await?;
+
+                let locked_package_id = lockfile.packages_matching(dep.clone());
+                let dep = if let Some(locked_package_id) = locked_package_id {
+                    rewrite_locked_dependency(dep.clone(), locked_package_id?)
+                } else {
+                    dep
+                };
+
+                let results = registry.query(&dep).await?;
+
+                let Some(dep_summary) = results.first() else {
+                    bail!("cannot find package {}", dep.name)
+                };
+
+                let dep_target_kind: Option<TargetKind> = match dep.kind.clone() {
+                    DepKind::Normal => None,
+                    DepKind::Target(target_kind) => Some(target_kind),
+                };
+                let dep = dep_summary.package_id;
+
+                if let Some(existing) = packages.get(dep.name.as_ref()) {
+                    if existing.source_id != dep.source_id {
+                        bail!(
+                            indoc! {"
+                            found dependencies on the same package `{}` coming from incompatible \
+                            sources:
+                            source 1: {}
+                            source 2: {}
+                            "},
+                            dep.name,
+                            existing.source_id,
+                            dep.source_id
+                        );
+                    }
+                }
+
+                let weight = graph
+                    .edge_weight(package_id, dep)
+                    .cloned()
+                    .unwrap_or_default();
+                let weight = weight.extend(dep_target_kind);
+                graph.add_edge(package_id, dep, weight);
+                summaries.insert(dep, dep_summary.clone());
+
+                if packages.contains_key(dep.name.as_ref()) {
+                    continue;
+                }
+
+                packages.insert(dep.name.clone(), dep);
+                next_queue.push(dep);
+            }
+        }
+
+        queue = next_queue;
+    }
+
+    // Detect incompatibilities and bail in case ones are found.
+    let mut incompatibilities = Vec::new();
+    for from_package in graph.nodes() {
+        let dep_filter = DependencyFilter::propagation(main_packages.contains(&from_package));
+        for manifest_dependency in summaries[&from_package].filtered_full_dependencies(dep_filter) {
+            let to_package = packages[&manifest_dependency.name];
+            if !manifest_dependency.matches_package_id(to_package) {
+                let message = format!(
+                    "- {from_package} cannot use {to_package}, because {} requires {} {}",
+                    from_package.name, to_package.name, manifest_dependency.version_req
+                );
+                incompatibilities.push(message);
+            }
+        }
+    }
+
+    if !incompatibilities.is_empty() {
+        incompatibilities.sort();
+        let incompatibilities = incompatibilities.join("\n");
+        bail!(formatdoc! {"
+            Version solving failed:
+            {incompatibilities}
+
+            Scarb does not have real version solving algorithm yet.
+            Perhaps in the future this conflict could be resolved, but currently,
+            please upgrade your dependencies to use latest versions of their dependencies.
+        "});
+    }
+
+    let resolve = Resolve { graph, summaries };
+    resolve.check_checksums(&lockfile)?;
+    Ok(resolve)
+}
+
+fn rewrite_locked_dependency(
+    dependency: ManifestDependency,
+    locked_package_id: PackageId,
+) -> ManifestDependency {
+    ManifestDependency::builder()
+        .kind(dependency.kind.clone())
+        .name(dependency.name.clone())
+        .source_id(locked_package_id.source_id)
+        .version_req(DependencyVersionReq::Locked {
+            exact: locked_package_id.version.clone(),
+            req: dependency.version_req.clone().into(),
+        })
+        .build()
+}
+
+async fn rewrite_dependency_source_id(
+    registry: &dyn Registry,
+    package_id: &PackageId,
+    dependency: &ManifestDependency,
+) -> anyhow::Result<ManifestDependency> {
+    // Rewrite path dependencies for git sources.
+    if package_id.source_id.is_git() && dependency.source_id.is_path() {
+        let rewritten_dep = ManifestDependency::builder()
+            .kind(dependency.kind.clone())
+            .name(dependency.name.clone())
+            .source_id(package_id.source_id)
+            .version_req(dependency.version_req.clone())
+            .build();
+        // Check if this dependency can be queried from git source.
+        // E.g. packages below other package's manifest will not be accessible.
+        if !registry.query(&rewritten_dep).await?.is_empty() {
+            // If it is, return rewritten dependency.
+            return Ok(rewritten_dep);
+        }
+    };
+
+    Ok(dependency.clone())
+}