diff --git a/.jules/bolt.md b/.jules/bolt.md
index b140c4a7c..ea7f6386b 100644
--- a/.jules/bolt.md
+++ b/.jules/bolt.md
@@ -5,3 +5,7 @@
 ## 2024-05-19 - Caching YAML Load for Framework Registry
 **Learning:** `yaml.safe_load` on `frameworks.yml` within `load_framework_registry()` was taking ~2-3 ms per call and it was repeatedly called for every framework entry via `get_framework_config()`. This was a micro-bottleneck, especially when dealing with lists or multiple frameworks.
 **Action:** Applied the `@lru_cache` and `deepcopy` pattern successfully again to `load_framework_registry()` and `get_framework_config()` to avoid caching a mutable dictionary directly and avoid repeated YAML I/O parsing.
+
+## 2024-05-20 - Faster pandas iteration
+**Learning:** Iterating over pandas DataFrames with `.iterrows()` is a significant performance bottleneck due to series object creation overhead.
+**Action:** Replace `.iterrows()` with `.itertuples(index=False, name=None)` for standard tuple returns or `.to_dict("records")` when dictionary/dynamic property access is needed.
diff --git a/ml_peg/calcs/bulk_crystal/elasticity/calc_elasticity.py b/ml_peg/calcs/bulk_crystal/elasticity/calc_elasticity.py
index d57dac3e0..57f7939f2 100644
--- a/ml_peg/calcs/bulk_crystal/elasticity/calc_elasticity.py
+++ b/ml_peg/calcs/bulk_crystal/elasticity/calc_elasticity.py
@@ -301,7 +301,8 @@ def run_elasticity_benchmark(
         else {}
     )
     atoms_list = []
-    for _, row in results.iterrows():
+    # ⚡ Bolt: Use to_dict('records') over iterrows for faster iteration.
+    for row in results.to_dict("records"):
         struct = row.get("final_structure")
         if not isinstance(struct, Structure):
             struct = mock_ref_map.get(row[benchmark.index_name])
diff --git a/ml_peg/calcs/conformers/MPCONF196/calc_MPCONF196.py b/ml_peg/calcs/conformers/MPCONF196/calc_MPCONF196.py
index a033fabf2..1f732cae0 100644
--- a/ml_peg/calcs/conformers/MPCONF196/calc_MPCONF196.py
+++ b/ml_peg/calcs/conformers/MPCONF196/calc_MPCONF196.py
@@ -86,9 +86,10 @@ def get_ref_energies(data_path: Path) -> dict[str, float]:
     )
     ref_energies = {}
 
-    for row in df.iterrows():
-        label = row[1][0]
-        ref_energies[label] = float(row[1][2]) * KCAL_TO_EV
+    # ⚡ Bolt: Use itertuples over iterrows for faster iteration.
+    for row in df.itertuples(index=False, name=None):
+        label = row[0]
+        ref_energies[label] = float(row[2]) * KCAL_TO_EV
 
     return ref_energies
 
diff --git a/ml_peg/calcs/conformers/solvMPCONF196/calc_solvMPCONF196.py b/ml_peg/calcs/conformers/solvMPCONF196/calc_solvMPCONF196.py
index be51974af..bc473a412 100644
--- a/ml_peg/calcs/conformers/solvMPCONF196/calc_solvMPCONF196.py
+++ b/ml_peg/calcs/conformers/solvMPCONF196/calc_solvMPCONF196.py
@@ -84,9 +84,10 @@ def get_ref_energies(data_path: Path) -> dict[str, float]:
     )
     ref_energies = {}
 
-    for row in df.iterrows():
-        label = row[1][0]
-        e_ref = float(row[1][1]) * units.Hartree
+    # ⚡ Bolt: Use itertuples over iterrows for faster iteration.
+    for row in df.itertuples(index=False, name=None):
+        label = row[0]
+        e_ref = float(row[1]) * units.Hartree
         ref_energies[label] = e_ref
 
     return ref_energies
diff --git a/ml_peg/calcs/utils/gscdb138.py b/ml_peg/calcs/utils/gscdb138.py
index 0fc26c1e0..0a307c444 100644
--- a/ml_peg/calcs/utils/gscdb138.py
+++ b/ml_peg/calcs/utils/gscdb138.py
@@ -106,11 +106,14 @@ def run_gscdb138(
         df_refs["Reference"] *= units.Hartree
 
         # Calculate relative energy for each entry.
-        for _, row in tqdm(df_refs.iterrows(), dataset, total=df_refs.shape[0]):
+        # ⚡ Bolt: Use itertuples over iterrows for faster iteration.
+        for row in tqdm(
+            df_refs.itertuples(index=False), dataset, total=df_refs.shape[0]
+        ):
             atoms_list = []
-            identifier = row["Reaction"]
-            reactions = row["Stoichiometry"].split(",")  # Parse stoichiometry string.
-            e_rel_ref = row["Reference"]
+            identifier = row.Reaction
+            reactions = row.Stoichiometry.split(",")  # Parse stoichiometry string.
+            e_rel_ref = row.Reference
             num_species = len(reactions) // 2  # Each species has coefficient and name.
 
             e_rel_model = 0