diff --git a/backend/reconcile/src/diffs/lcs.rs b/backend/reconcile/src/diffs/lcs.rs
deleted file mode 100644
index 511fdd43..00000000
--- a/backend/reconcile/src/diffs/lcs.rs
+++ /dev/null
@@ -1,165 +0,0 @@
-//! LCS diff algorithm.
-//!
-//! * time: `O((NM)D log (M)D)`
-//! * space `O(MN)`
-use std::collections::BTreeMap;
-use std::ops::{Index, Range};
-
-use crate::tokenizer::token::Token;
-
-use super::raw_operation::RawOperation;
-use super::utils::{common_prefix_len, common_suffix_len};
-
-/// LCS diff algorithm.
-/// Copied from https://github.com/mitsuhiko/similar/blob/7e15c44de11a1cd61e1149189929e189ef977fd8/src/algorithms/lcs.rs
-pub fn diff(old: &[Token], new: &[Token]) -> Vec<RawOperation> {
-    let common_prefix_len = common_prefix_len(old, 0..old.len(), new, 0..new.len());
-    let common_suffix_len = common_suffix_len(
-        old,
-        common_prefix_len..old.len(),
-        new,
-        common_prefix_len..new.len(),
-    );
-
-    let maybe_table = make_table(
-        old,
-        common_prefix_len..(old.len() - common_suffix_len),
-        new,
-        common_prefix_len..(new.len() - common_suffix_len),
-    );
-    let mut old_idx = 0;
-    let mut new_idx = 0;
-    let new_len = new.len() - common_prefix_len - common_suffix_len;
-    let old_len = old.len() - common_prefix_len - common_suffix_len;
-
-    let mut result: Vec<RawOperation> = Vec::new();
-    if common_prefix_len > 0 {
-        result.push(RawOperation::Equal(old[0..common_prefix_len].to_vec()));
-    }
-
-    if let Some(table) = maybe_table {
-        while new_idx < new_len && old_idx < old_len {
-            let old_orig_idx = common_prefix_len + old_idx;
-            let new_orig_idx = common_prefix_len + new_idx;
-
-            if new[new_orig_idx] == old[old_orig_idx] {
-                result.push(RawOperation::Equal(vec![old[old_orig_idx].clone()]));
-                old_idx += 1;
-                new_idx += 1;
-            } else if table.get(&(new_idx, old_idx + 1)).unwrap_or(&0)
-                >= table.get(&(new_idx + 1, old_idx)).unwrap_or(&0)
-            {
-                result.push(RawOperation::Delete(vec![old[old_orig_idx].clone()]));
-                old_idx += 1;
-            } else {
-                result.push(RawOperation::Insert(vec![new[new_orig_idx].clone()]));
-                new_idx += 1;
-            }
-        }
-    } else {
-        let old_orig_idx = common_prefix_len + old_idx;
-        let new_orig_idx = common_prefix_len + new_idx;
-
-        result.push(RawOperation::Delete(
-            old[old_orig_idx..old_orig_idx + old_len].to_vec(),
-        ));
-        result.push(RawOperation::Insert(
-            new[new_orig_idx..new_orig_idx + new_len].to_vec(),
-        ));
-    }
-
-    if old_idx < old_len {
-        result.push(RawOperation::Delete(
-            old[common_prefix_len + old_idx..common_prefix_len + old_len].to_vec(),
-        ));
-        old_idx += old_len - old_idx;
-    }
-
-    if new_idx < new_len {
-        result.push(RawOperation::Insert(
-            new[common_prefix_len + new_idx..common_prefix_len + new_len].to_vec(),
-        ));
-    }
-
-    if common_suffix_len > 0 {
-        result.push(RawOperation::Equal(
-            old[old_len + common_prefix_len..old_len + common_prefix_len + common_suffix_len]
-                .to_vec(),
-        ));
-    }
-
-    result
-}
-
-fn make_table<Old, New>(
-    old: &Old,
-    old_range: Range<usize>,
-    new: &New,
-    new_range: Range<usize>,
-) -> Option<BTreeMap<(usize, usize), u32>>
-where
-    Old: Index<usize> + ?Sized,
-    New: Index<usize> + ?Sized,
-    New::Output: PartialEq<Old::Output>,
-{
-    let old_len = old_range.len();
-    let new_len = new_range.len();
-    let mut table = BTreeMap::new();
-
-    for i in (0..new_len).rev() {
-        for j in (0..old_len).rev() {
-            let val = if new[i] == old[j] {
-                table.get(&(i + 1, j + 1)).unwrap_or(&0) + 1
-            } else {
-                *table
-                    .get(&(i + 1, j))
-                    .unwrap_or(&0)
-                    .max(table.get(&(i, j + 1)).unwrap_or(&0))
-            };
-            if val > 0 {
-                table.insert((i, j), val);
-            }
-        }
-    }
-
-    Some(table)
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use pretty_assertions::assert_eq;
-    use std::collections::BTreeMap;
-
-    #[test]
-    fn test_table() {
-        let table = make_table(&vec![2, 3], 0..2, &vec![0, 1, 2], 0..3).unwrap();
-        let expected = {
-            let mut m = BTreeMap::new();
-            m.insert((1, 0), 1);
-            m.insert((0, 0), 1);
-            m.insert((2, 0), 1);
-            m
-        };
-        assert_eq!(table, expected);
-    }
-
-    #[test]
-    fn test_empty_examples() {
-        assert_eq!(diff(&[], &[]), vec![]);
-        assert_eq!(
-            diff(&[Token::new("a".to_string(), "a".to_string())], &[]),
-            vec![RawOperation::Delete(vec![Token::new(
-                "a".to_string(),
-                "a".to_string()
-            )])]
-        );
-        assert_eq!(
-            diff(&[], &[Token::new("a".to_string(), "a".to_string())]),
-            vec![RawOperation::Insert(vec![Token::new(
-                "a".to_string(),
-                "a".to_string()
-            )])]
-        );
-    }
-}
diff --git a/backend/reconcile/src/diffs/mod.rs b/backend/reconcile/src/diffs/mod.rs
index 79534923..64b0536b 100644
--- a/backend/reconcile/src/diffs/mod.rs
+++ b/backend/reconcile/src/diffs/mod.rs
@@ -1,4 +1,3 @@
-pub mod lcs;
 pub mod myers;
 pub mod raw_operation;
 mod utils;