diff --git a/conda_build/config.py b/conda_build/config.py
index 5d4ba590d3..99c6853def 100644
--- a/conda_build/config.py
+++ b/conda_build/config.py
@@ -8,6 +8,7 @@
 import copy
 import math
 import os
+import pickle
 import re
 import shutil
 import time
@@ -822,9 +823,16 @@ def clean_pkgs(self):
 
     def copy(self):
         new = copy.copy(self)
-        new.variant = copy.deepcopy(self.variant)
+        # Use picke.loads(pickle.dumps(...) as a faster deepcopy alternative, if possible.
+        try:
+            new.variant = pickle.loads(pickle.dumps(self.variant, -1))
+        except:
+            new.variant = copy.deepcopy(self.variant)
         if hasattr(self, "variants"):
-            new.variants = copy.deepcopy(self.variants)
+            try:
+                new.variants = pickle.loads(pickle.dumps(self.variants, -1))
+            except:
+                new.variants = copy.deepcopy(self.variants)
         return new
 
     # context management - automatic cleanup if self.dirty or self.keep_old_work is not True
diff --git a/conda_build/metadata.py b/conda_build/metadata.py
index 633b6de8fc..a5bcd938a0 100644
--- a/conda_build/metadata.py
+++ b/conda_build/metadata.py
@@ -109,6 +109,31 @@ def remove_constructor(cls, tag):
 # used to avoid recomputing/rescanning recipe contents for used variables
 used_vars_cache = {}
 
+# Placeholders singletons for os/os.environ used to memoize select_lines().
+_selector_placeholder_os = object()
+_selector_placeholder_os_environ = object()
+
+
+@lru_cache(maxsize=200)
+def re_findall(pattern, text, flags=0):
+    if isinstance(pattern, re.Pattern):
+        return pattern.findall(text, flags)
+    return re.findall(pattern, text, flags)
+
+
+@lru_cache(maxsize=200)
+def re_match(pattern, text, flags=0):
+    if isinstance(pattern, re.Pattern):
+        return pattern.match(text, flags)
+    return re.match(pattern, text, flags)
+
+
+@lru_cache(maxsize=200)
+def re_search(pattern, text, flags=0):
+    if isinstance(pattern, re.Pattern):
+        return pattern.search(text, flags)
+    return re.search(pattern, text, flags)
+
 
 def get_selectors(config: Config) -> dict[str, bool]:
     """Aggregates selectors for use in recipe templating.
@@ -241,7 +266,7 @@ def ns_cfg(config: Config) -> dict[str, bool]:
 # "NameError: name 'var' is not defined", where var is the variable that is not defined. This gets
 #    returned
 def parseNameNotFound(error):
-    m = re.search("'(.+?)'", str(error))
+    m = re_search("'(.+?)'", str(error))
     if len(m.groups()) == 1:
         return m.group(1)
     else:
@@ -268,6 +293,58 @@ def eval_selector(selector_string, namespace, variants_in_place):
 
 
 def select_lines(data, namespace, variants_in_place):
+    # Try to turn namespace into a hashable representation for memoization.
+    try:
+        namespace_copy = namespace.copy()
+        if namespace_copy.get("os") is os:
+            namespace_copy["os"] = _selector_placeholder_os
+        if namespace_copy.get("environ") is os.environ:
+            namespace_copy["environ"] = _selector_placeholder_os_environ
+        if "pin_run_as_build" in namespace_copy:
+            # This raises TypeError if pin_run_as_build is not a dict of dicts.
+            try:
+                namespace_copy["pin_run_as_build"] = tuple(
+                    (key, tuple((k, v) for k, v in value.items()))
+                    for key, value in namespace_copy["pin_run_as_build"].items()
+                )
+            except (AttributeError, TypeError, ValueError):
+                # AttributeError: no .items method
+                # TypeError: .items() not iterable of iterables
+                # ValueError: .items() not iterable of only (k, v) tuples
+                raise TypeError
+        for k, v in namespace_copy.items():
+            # Convert list/sets/tuple to tuples (of tuples if it contains
+            # list/set elements). Copy any other type verbatim and rather fall
+            # back to the non-memoized version to avoid wrong/lossy conversions.
+            if isinstance(v, (list, set, tuple)):
+                namespace_copy[k] = tuple(
+                    tuple(e) if isinstance(e, (list, set)) else e for e in v
+                )
+        namespace_tuple = tuple(namespace_copy.items())
+        # Raise TypeError if anything in namespace_tuple is not hashable.
+        hash(namespace_tuple)
+    except TypeError:
+        return _select_lines(data, namespace, variants_in_place)
+    return _select_lines_memoized(data, namespace_tuple, variants_in_place)
+
+
+@lru_cache(maxsize=200)
+def _select_lines_memoized(data, namespace_tuple, variants_in_place):
+    # Convert namespace_tuple to dict and undo the os/environ/pin_run_as_build
+    # replacements done in select_lines.
+    namespace = dict(namespace_tuple)
+    if namespace.get("os") is _selector_placeholder_os:
+        namespace["os"] = os
+    if namespace.get("environ") is _selector_placeholder_os_environ:
+        namespace["environ"] = os.environ
+    if "pin_run_as_build" in namespace:
+        namespace["pin_run_as_build"] = {
+            key: dict(value) for key, value in namespace["pin_run_as_build"]
+        }
+    return _select_lines(data, namespace, variants_in_place)
+
+
+def _select_lines(data, namespace, variants_in_place):
     lines = []
 
     for i, line in enumerate(data.splitlines()):
@@ -280,8 +357,7 @@ def select_lines(data, namespace, variants_in_place):
         if line.lstrip().startswith("#"):
             # Don't bother with comment only lines
             continue
-        m = sel_pat.match(line)
-        if m:
+        if "[" in line and "]" in line and (m := re_match(sel_pat, line)):
             cond = m.group(3)
             try:
                 if eval_selector(cond, namespace, variants_in_place):
@@ -888,8 +964,8 @@ def get_output_dicts_from_metadata(metadata, outputs=None):
             outputs.append(OrderedDict(name=metadata.name()))
     for out in outputs:
         if (
-            "package:" in metadata.get_recipe_text()
-            and out.get("name") == metadata.name()
+            out.get("name") == metadata.name()
+            and "package:" in metadata.get_recipe_text()
         ):
             combine_top_level_metadata_with_output(metadata, out)
     return outputs
@@ -1014,9 +1090,10 @@ def get_updated_output_dict_from_reparsed_metadata(original_dict, new_outputs):
     return output_d
 
 
+@lru_cache(maxsize=200)
 def _filter_recipe_text(text, extract_pattern=None):
     if extract_pattern:
-        match = re.search(extract_pattern, text, flags=re.MULTILINE | re.DOTALL)
+        match = re_search(extract_pattern, text, flags=re.MULTILINE | re.DOTALL)
         text = (
             "\n".join({string for string in match.groups() if string}) if match else ""
         )
@@ -1622,7 +1699,7 @@ def get_hash_contents(self):
             dependencies = [
                 req
                 for req in dependencies
-                if not exclude_pattern.match(req) or " " in self.config.variant[req]
+                if not re_match(exclude_pattern, req) or " " in self.config.variant[req]
             ]
 
         # retrieve values - this dictionary is what makes up the hash.
@@ -1666,12 +1743,11 @@ def build_id(self):
             raise RuntimeError(
                 f"Couldn't extract raw recipe text for {self.name()} output"
             )
-        raw_recipe_text = self.extract_package_and_build_text()
-        raw_manual_build_string = re.search(r"\s*string:", raw_recipe_text)
+        raw_manual_build_string = re_search(r"\s*string:", raw_recipe_text)
         # user setting their own build string.  Don't modify it.
         if manual_build_string and not (
             raw_manual_build_string
-            and re.findall(r"h\{\{\s*PKG_HASH\s*\}\}", raw_manual_build_string.string)
+            and re_findall(r"h\{\{\s*PKG_HASH\s*\}\}", raw_manual_build_string.string)
         ):
             check_bad_chrs(manual_build_string, "build/string")
             out = manual_build_string
@@ -1680,7 +1756,7 @@ def build_id(self):
             out = build_string_from_metadata(self)
             if self.config.filename_hashing and self.final:
                 hash_ = self.hash_dependencies()
-                if not re.findall("h[0-9a-f]{%s}" % self.config.hash_length, out):
+                if not re_findall("h[0-9a-f]{%s}" % self.config.hash_length, out):
                     ret = out.rsplit("_", 1)
                     try:
                         int(ret[0])
@@ -2038,7 +2114,7 @@ def uses_jinja(self):
             return False
         with open(self.meta_path, "rb") as f:
             meta_text = UnicodeDammit(f.read()).unicode_markup
-            matches = re.findall(r"{{.*}}", meta_text)
+            matches = re_findall(r"{{.*}}", meta_text)
         return len(matches) > 0
 
     @property
@@ -2053,7 +2129,7 @@ def uses_vcs_in_meta(self) -> Literal["git", "svn", "mercurial"] | None:
             with open(self.meta_path, "rb") as f:
                 meta_text = UnicodeDammit(f.read()).unicode_markup
                 for _vcs in vcs_types:
-                    matches = re.findall(rf"{_vcs.upper()}_[^\.\s\'\"]+", meta_text)
+                    matches = re_findall(rf"{_vcs.upper()}_[^\.\s\'\"]+", meta_text)
                     if len(matches) > 0 and _vcs != self.get_value("package/name"):
                         if _vcs == "hg":
                             _vcs = "mercurial"
@@ -2076,7 +2152,7 @@ def uses_vcs_in_build(self) -> Literal["git", "svn", "mercurial"] | None:
                         #   1. the vcs command, optionally with an exe extension
                         #   2. a subcommand - for example, "clone"
                         #   3. a target url or other argument
-                        matches = re.findall(
+                        matches = re_findall(
                             rf"{vcs}(?:\.exe)?(?:\s+\w+\s+[\w\/\.:@]+)",
                             build_script,
                             flags=re.IGNORECASE,
@@ -2146,7 +2222,7 @@ def extract_single_output_text(
         # first, need to figure out which index in our list of outputs the name matches.
         #    We have to do this on rendered data, because templates can be used in output names
         recipe_text = self.extract_outputs_text(apply_selectors=apply_selectors)
-        output_matches = output_re.findall(recipe_text)
+        output_matches = re_findall(output_re, recipe_text)
         outputs = self.meta.get("outputs") or (
             self.parent_outputs if hasattr(self, "parent_outputs") else None
         )
@@ -2187,15 +2263,15 @@ def numpy_xx(self) -> bool:
         """This is legacy syntax that we need to support for a while.  numpy x.x means
         "pin run as build" for numpy.  It was special-cased to only numpy."""
         text = self.extract_requirements_text()
-        return bool(numpy_xx_re.search(text))
+        return bool(re_search(numpy_xx_re, text))
 
     @property
     def uses_numpy_pin_compatible_without_xx(self) -> tuple[bool, bool]:
         text = self.extract_requirements_text()
-        compatible_search = numpy_compatible_re.search(text)
+        compatible_search = re_search(numpy_compatible_re, text)
         max_pin_search = None
         if compatible_search:
-            max_pin_search = numpy_compatible_x_re.search(text)
+            max_pin_search = re_search(numpy_compatible_x_re, text)
         # compatible_search matches simply use of pin_compatible('numpy')
         # max_pin_search quantifies the actual number of x's in the max_pin field.  The max_pin
         #     field can be absent, which is equivalent to a single 'x'
@@ -2212,7 +2288,8 @@ def uses_subpackage(self):
             if "name" in out:
                 name_re = re.compile(r"^{}(\s|\Z|$)".format(out["name"]))
                 in_reqs = any(
-                    name_re.match(req) for req in self.get_depends_top_and_out("run")
+                    re_match(name_re, req)
+                    for req in self.get_depends_top_and_out("run")
                 )
                 if in_reqs:
                     break
@@ -2220,13 +2297,13 @@ def uses_subpackage(self):
         if not in_reqs and self.meta_path:
             data = self.extract_requirements_text(force_top_level=True)
             if data:
-                subpackage_pin = re.search(r"{{\s*pin_subpackage\(.*\)\s*}}", data)
+                subpackage_pin = re_search(r"{{\s*pin_subpackage\(.*\)\s*}}", data)
         return in_reqs or bool(subpackage_pin)
 
     @property
     def uses_new_style_compiler_activation(self):
         text = self.extract_requirements_text()
-        return bool(re.search(r"\{\{\s*compiler\(.*\)\s*\}\}", text))
+        return bool(re_search(r"\{\{\s*compiler\(.*\)\s*\}\}", text))
 
     def validate_features(self):
         if any(
@@ -2287,7 +2364,7 @@ def variant_in_source(self):
             # We use this variant in the top-level recipe.
             # constrain the stored variants to only this version in the output
             #     variant mapping
-            if re.search(
+            if re_search(
                 r"\s*\{\{\s*%s\s*(?:.*?)?\}\}" % key, self.extract_source_text()
             ):
                 return True
@@ -2371,15 +2448,19 @@ def get_output_metadata(self, output):
                 )
                 if build_reqs:
                     build_reqs = [
-                        req for req in build_reqs if not subpackage_pattern.match(req)
+                        req
+                        for req in build_reqs
+                        if not re_match(subpackage_pattern, req)
                     ]
                 if host_reqs:
                     host_reqs = [
-                        req for req in host_reqs if not subpackage_pattern.match(req)
+                        req
+                        for req in host_reqs
+                        if not re_match(subpackage_pattern, req)
                     ]
                 if run_reqs:
                     run_reqs = [
-                        req for req in run_reqs if not subpackage_pattern.match(req)
+                        req for req in run_reqs if not re_match(subpackage_pattern, req)
                     ]
 
             requirements = {}
@@ -2642,12 +2723,13 @@ def get_loop_vars(self):
         return variants.get_vars(_variants, loop_only=True)
 
     def get_used_loop_vars(self, force_top_level=False, force_global=False):
+        loop_vars = set(self.get_loop_vars())
         return {
             var
             for var in self.get_used_vars(
                 force_top_level=force_top_level, force_global=force_global
             )
-            if var in self.get_loop_vars()
+            if var in loop_vars
         }
 
     def get_rendered_recipe_text(
@@ -2813,7 +2895,7 @@ def _get_used_vars_meta_yaml_helper(
             reqs_re = re.compile(
                 r"requirements:.+?(?=^\w|\Z|^\s+-\s(?=name|type))", flags=re.M | re.S
             )
-            reqs_text = reqs_re.search(recipe_text)
+            reqs_text = re_search(reqs_re, recipe_text)
             reqs_text = reqs_text.group() if reqs_text else ""
 
         return reqs_text, recipe_text
diff --git a/conda_build/variants.py b/conda_build/variants.py
index 2ece5f4bd6..1627dcc5df 100644
--- a/conda_build/variants.py
+++ b/conda_build/variants.py
@@ -707,16 +707,14 @@ def get_package_variants(recipedir_or_metadata, config=None, variants=None):
 def get_vars(variants, loop_only=False):
     """For purposes of naming/identifying, provide a way of identifying which variables contribute
     to the matrix dimensionality"""
+    first_variant, *other_variants = variants
     special_keys = {"pin_run_as_build", "zip_keys", "ignore_version"}
-    special_keys.update(set(ensure_list(variants[0].get("extend_keys"))))
+    special_keys.update(set(ensure_list(first_variant.get("extend_keys"))))
     loop_vars = [
         k
-        for k in variants[0]
+        for k, v in first_variant.items()
         if k not in special_keys
-        and (
-            not loop_only
-            or any(variant[k] != variants[0][k] for variant in variants[1:])
-        )
+        and (not loop_only or any(variant[k] != v for variant in other_variants))
     ]
     return loop_vars
 
@@ -773,7 +771,9 @@ def find_used_variables_in_shell_script(variant, file_path):
         text = f.read()
     used_variables = set()
     for v in variant:
-        variant_regex = r"(^[^$]*?\$\{?\s*%s\s*[\s|\}])" % v
+        if v not in text:
+            continue
+        variant_regex = rf"(^[^$]*?\$\{{?\s*{re.escape(v)}\s*[\s|\}}])"
         if re.search(variant_regex, text, flags=re.MULTILINE | re.DOTALL):
             used_variables.add(v)
     return used_variables
@@ -784,7 +784,9 @@ def find_used_variables_in_batch_script(variant, file_path):
         text = f.read()
     used_variables = set()
     for v in variant:
-        variant_regex = r"\%" + v + r"\%"
+        if v not in text:
+            continue
+        variant_regex = rf"\%{re.escape(v)}\%"
         if re.search(variant_regex, text, flags=re.MULTILINE | re.DOTALL):
             used_variables.add(v)
     return used_variables
diff --git a/news/5225-render-misc-speedups b/news/5225-render-misc-speedups
new file mode 100644
index 0000000000..c6f84eab00
--- /dev/null
+++ b/news/5225-render-misc-speedups
@@ -0,0 +1,19 @@
+### Enhancements
+
+* Miscellaneous recipe rendering speed ups. (#5224 via #5225)
+
+### Bug fixes
+
+* <news item>
+
+### Deprecations
+
+* <news item>
+
+### Docs
+
+* <news item>
+
+### Other
+
+* <news item>