diff --git a/.github/workflows/style-check.yml b/.github/workflows/style-check.yml
index 45dc0a1..b0ab073 100644
--- a/.github/workflows/style-check.yml
+++ b/.github/workflows/style-check.yml
@@ -13,10 +13,12 @@ jobs:
           python-version: 3.9
       - name: Install requirements
         run: pip install -r requirements.txt
+      - name: Install test requirements
+        run: pip install -r test-requirements.txt
       - name: Install pylint
         run: pip install pylint
       - name: Run pylint
-        run: pylint -E generate.py
+        run: find . -type f -name "*.py" | xargs pylint -E
   black:
     name: black
     runs-on: ubuntu-latest
@@ -46,4 +48,4 @@ jobs:
       - name: Install isort
         run: pip install isort
       - name: Run isort
-        run: isort --ensure-newline-before-comments --diff generate.py
+        run: isort --ensure-newline-before-comments --diff -v .
diff --git a/.github/workflows/type-check.yml b/.github/workflows/type-check.yml
index bc2e492..e6581f4 100644
--- a/.github/workflows/type-check.yml
+++ b/.github/workflows/type-check.yml
@@ -19,3 +19,20 @@ jobs:
         run: pip install mypy
       - name: Run mypy
         run: mypy .
+  pyre:
+    name: pyre
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@master
+      - name: Set up Python 3.9
+        uses: actions/setup-python@v1
+        with:
+          python-version: 3.9
+      - name: Install requirements
+        run: pip install -r requirements.txt
+      - name: Install test requirements
+        run: pip install -r test-requirements.txt
+      - name: Install pyre
+        run: pip install pyre
+      - name: Run pyre
+        run: pyre check
diff --git a/.pyre_configuration b/.pyre_configuration
index 9573b80..cf73b56 100644
--- a/.pyre_configuration
+++ b/.pyre_configuration
@@ -1,5 +1,7 @@
 {
   "source_directories": [
     "."
-  ]
+  ],
+  "site_package_search_strategy": "all",
+  "strict": true
 }
diff --git a/generate.py b/generate.py
index 91a516a..dafcfc5 100755
--- a/generate.py
+++ b/generate.py
@@ -8,7 +8,7 @@
 import asyncio
 import logging
 from pathlib import Path
-from typing import Any, Coroutine, List
+from typing import Any, Awaitable, Callable, Coroutine, List
 
 # https://github.com/kerrickstaley/genanki
 import genanki  # type: ignore
@@ -34,7 +34,7 @@ def parse_args() -> argparse.Namespace:
         "--start", type=int, help="Start generation from this problem", default=0
     )
     parser.add_argument(
-        "--stop", type=int, help="Stop generation on this problem", default=2 ** 64
+        "--stop", type=int, help="Stop generation on this problem", default=2**64
     )
     parser.add_argument(
         "--page-size",
@@ -64,7 +64,7 @@ class LeetcodeNote(genanki.Note):
     """
 
     @property
-    def guid(self):
+    def guid(self) -> str:
         # Hash by leetcode task handle
         return genanki.guid_for(self.fields[0])
 
@@ -179,7 +179,7 @@ async def generate(
         start, stop, page_size, list_id
     )
 
-    note_generators: List[Coroutine[Any, Any, LeetcodeNote]] = []
+    note_generators: List[Awaitable[LeetcodeNote]] = []
 
     task_handles = await leetcode_data.all_problems_handles()
 
@@ -212,5 +212,5 @@ async def main() -> None:
 
 
 if __name__ == "__main__":
-    loop = asyncio.get_event_loop()
+    loop: asyncio.events.AbstractEventLoop = asyncio.get_event_loop()
     loop.run_until_complete(main())
diff --git a/leetcode_anki/helpers/leetcode.py b/leetcode_anki/helpers/leetcode.py
index af318cb..f4ba87b 100644
--- a/leetcode_anki/helpers/leetcode.py
+++ b/leetcode_anki/helpers/leetcode.py
@@ -1,3 +1,4 @@
+# pylint: disable=missing-module-docstring
 import functools
 import json
 import logging
@@ -5,7 +6,7 @@
 import os
 import time
 from functools import cached_property
-from typing import Callable, Dict, List, Tuple, Type
+from typing import Any, Callable, Dict, List, Tuple, Type, TypeVar
 
 # https://github.com/prius/python-leetcode
 import leetcode.api.default_api  # type: ignore
@@ -48,16 +49,28 @@ def _get_leetcode_api_client() -> leetcode.api.default_api.DefaultApi:
     return api_instance
 
 
-def retry(times: int, exceptions: Tuple[Type[Exception]], delay: float) -> Callable:
-    """
-    Retry Decorator
-    Retries the wrapped function/method `times` times if the exceptions listed
-    in `exceptions` are thrown
-    """
+_T = TypeVar("_T")
+
+
+class _RetryDecorator:
+    _times: int
+    _exceptions: Tuple[Type[Exception]]
+    _delay: float
+
+    def __init__(
+        self, times: int, exceptions: Tuple[Type[Exception]], delay: float
+    ) -> None:
+        self._times = times
+        self._exceptions = exceptions
+        self._delay = delay
+
+    def __call__(self, func: Callable[..., _T]) -> Callable[..., _T]:
+        times: int = self._times
+        exceptions: Tuple[Type[Exception]] = self._exceptions
+        delay: float = self._delay
 
-    def decorator(func):
         @functools.wraps(func)
-        def wrapper(*args, **kwargs):
+        def wrapper(*args: Any, **kwargs: Any) -> _T:
             for attempt in range(times - 1):
                 try:
                     return func(*args, **kwargs)
@@ -72,7 +85,17 @@ def wrapper(*args, **kwargs):
 
         return wrapper
 
-    return decorator
+
+def retry(
+    times: int, exceptions: Tuple[Type[Exception]], delay: float
+) -> _RetryDecorator:
+    """
+    Retry Decorator
+    Retries the wrapped function/method `times` times if the exceptions listed
+    in `exceptions` are thrown
+    """
+
+    return _RetryDecorator(times, exceptions, delay)
 
 
 class LeetcodeData:
@@ -230,7 +253,7 @@ def _get_problems_data(
             leetcode.models.graphql_question_detail.GraphqlQuestionDetail
         ] = []
 
-        logging.info(f"Fetching {stop - start + 1} problems {page_size} per page")
+        logging.info("Fetching %s problems %s per page", stop - start + 1, page_size)
 
         for page in tqdm(
             range(math.ceil((stop - start + 1) / page_size)),
@@ -261,6 +284,8 @@ def _get_problem_data(
         if problem_slug in cache:
             return cache[problem_slug]
 
+        raise ValueError(f"Problem {problem_slug} is not in cache")
+
     async def _get_description(self, problem_slug: str) -> str:
         """
         Problem description
diff --git a/pyproject.toml b/pyproject.toml
index 00a86b1..953fe9f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -3,3 +3,7 @@ asyncio_mode = "strict"
 testpaths = [
     "test",
 ]
+
+[tool.pylint]
+max-line-length = 88
+disable = ["line-too-long"]
diff --git a/test/helpers/test_leetcode.py b/test/helpers/test_leetcode.py
index 832f52f..bd74443 100644
--- a/test/helpers/test_leetcode.py
+++ b/test/helpers/test_leetcode.py
@@ -77,10 +77,14 @@ def dummy_return_question_detail_dict(
 @mock.patch("os.environ", mock.MagicMock(return_value={"LEETCODE_SESSION_ID": "test"}))
 @mock.patch("leetcode.auth", mock.MagicMock())
 class TestLeetcode:
+    # pyre-fixme[56]: Pyre was not able to infer the type of the decorator
+    #  `pytest.mark.asyncio`.
     @pytest.mark.asyncio
     async def test_get_leetcode_api_client(self) -> None:
         assert leetcode_anki.helpers.leetcode._get_leetcode_api_client()
 
+    # pyre-fixme[56]: Pyre was not able to infer the type of the decorator
+    #  `pytest.mark.asyncio`.
     @pytest.mark.asyncio
     async def test_retry(self) -> None:
         decorator = leetcode_anki.helpers.leetcode.retry(
@@ -134,6 +138,8 @@ def setup(self) -> None:
             0, 10000
         )
 
+    # pyre-fixme[56]: Pyre was not able to infer the type of the decorator
+    #  `pytest.mark.asyncio`.
     @pytest.mark.asyncio
     @mock.patch(
         "leetcode_anki.helpers.leetcode.LeetcodeData._get_problems_data",
@@ -142,6 +148,8 @@ def setup(self) -> None:
     async def test_init(self) -> None:
         self._leetcode_data._cache["test"] = QUESTION_DETAIL
 
+    # pyre-fixme[56]: Pyre was not able to infer the type of the decorator
+    #  `pytest.mark.asyncio`.
     @pytest.mark.asyncio
     @mock.patch(
         "leetcode_anki.helpers.leetcode.LeetcodeData._get_problems_data",
@@ -151,6 +159,8 @@ async def test_get_description(self) -> None:
         self._leetcode_data._cache["test"] = QUESTION_DETAIL
         assert (await self._leetcode_data.description("test")) == "test content"
 
+    # pyre-fixme[56]: Pyre was not able to infer the type of the decorator
+    #  `pytest.mark.asyncio`.
     @pytest.mark.asyncio
     @mock.patch(
         "leetcode_anki.helpers.leetcode.LeetcodeData._get_problems_data",
@@ -162,6 +172,8 @@ async def test_submissions(self) -> None:
         assert (await self._leetcode_data.submissions_total("test")) == 1
         assert (await self._leetcode_data.submissions_accepted("test")) == 1
 
+    # pyre-fixme[56]: Pyre was not able to infer the type of the decorator
+    #  `pytest.mark.asyncio`.
     @pytest.mark.asyncio
     @mock.patch(
         "leetcode_anki.helpers.leetcode.LeetcodeData._get_problems_data",
@@ -173,6 +185,8 @@ async def test_difficulty_easy(self) -> None:
         QUESTION_DETAIL.difficulty = "Easy"
         assert "Easy" in (await self._leetcode_data.difficulty("test"))
 
+    # pyre-fixme[56]: Pyre was not able to infer the type of the decorator
+    #  `pytest.mark.asyncio`.
     @pytest.mark.asyncio
     @mock.patch(
         "leetcode_anki.helpers.leetcode.LeetcodeData._get_problems_data",
@@ -184,6 +198,8 @@ async def test_difficulty_medium(self) -> None:
         QUESTION_DETAIL.difficulty = "Medium"
         assert "Medium" in (await self._leetcode_data.difficulty("test"))
 
+    # pyre-fixme[56]: Pyre was not able to infer the type of the decorator
+    #  `pytest.mark.asyncio`.
     @pytest.mark.asyncio
     @mock.patch(
         "leetcode_anki.helpers.leetcode.LeetcodeData._get_problems_data",
@@ -195,6 +211,8 @@ async def test_difficulty_hard(self) -> None:
         QUESTION_DETAIL.difficulty = "Hard"
         assert "Hard" in (await self._leetcode_data.difficulty("test"))
 
+    # pyre-fixme[56]: Pyre was not able to infer the type of the decorator
+    #  `pytest.mark.asyncio`.
     @pytest.mark.asyncio
     @mock.patch(
         "leetcode_anki.helpers.leetcode.LeetcodeData._get_problems_data",
@@ -205,6 +223,8 @@ async def test_paid(self) -> None:
 
         assert (await self._leetcode_data.paid("test")) is False
 
+    # pyre-fixme[56]: Pyre was not able to infer the type of the decorator
+    #  `pytest.mark.asyncio`.
     @pytest.mark.asyncio
     @mock.patch(
         "leetcode_anki.helpers.leetcode.LeetcodeData._get_problems_data",
@@ -215,6 +235,8 @@ async def test_problem_id(self) -> None:
 
         assert (await self._leetcode_data.problem_id("test")) == "1"
 
+    # pyre-fixme[56]: Pyre was not able to infer the type of the decorator
+    #  `pytest.mark.asyncio`.
     @pytest.mark.asyncio
     @mock.patch(
         "leetcode_anki.helpers.leetcode.LeetcodeData._get_problems_data",
@@ -225,6 +247,8 @@ async def test_likes(self) -> None:
 
         assert (await self._leetcode_data.likes("test")) == 1
 
+    # pyre-fixme[56]: Pyre was not able to infer the type of the decorator
+    #  `pytest.mark.asyncio`.
     @pytest.mark.asyncio
     @mock.patch(
         "leetcode_anki.helpers.leetcode.LeetcodeData._get_problems_data",
@@ -235,6 +259,8 @@ async def test_dislikes(self) -> None:
 
         assert (await self._leetcode_data.dislikes("test")) == 1
 
+    # pyre-fixme[56]: Pyre was not able to infer the type of the decorator
+    #  `pytest.mark.asyncio`.
     @pytest.mark.asyncio
     @mock.patch(
         "leetcode_anki.helpers.leetcode.LeetcodeData._get_problems_data",
@@ -248,6 +274,8 @@ async def test_tags(self) -> None:
             "difficulty-hard-tag",
         ]
 
+    # pyre-fixme[56]: Pyre was not able to infer the type of the decorator
+    #  `pytest.mark.asyncio`.
     @pytest.mark.asyncio
     @mock.patch(
         "leetcode_anki.helpers.leetcode.LeetcodeData._get_problems_data",
@@ -258,6 +286,8 @@ async def test_freq_bar(self) -> None:
 
         assert (await self._leetcode_data.freq_bar("test")) == 1.1
 
+    # pyre-fixme[56]: Pyre was not able to infer the type of the decorator
+    #  `pytest.mark.asyncio`.
     @pytest.mark.asyncio
     @mock.patch(
         "leetcode_anki.helpers.leetcode.LeetcodeData._get_problems_data",
@@ -267,6 +297,8 @@ async def test_get_problem_data(self) -> None:
         assert self._leetcode_data._cache["test"] == QUESTION_DETAIL
 
     @mock.patch("time.sleep", mock.Mock())
+    # pyre-fixme[56]: Pyre was not able to infer the type of the decorator
+    #  `pytest.mark.asyncio`.
     @pytest.mark.asyncio
     async def test_get_problems_data_page(self) -> None:
         data = leetcode.models.graphql_data.GraphqlData(
@@ -281,14 +313,20 @@ async def test_get_problems_data_page(self) -> None:
             QUESTION_DETAIL
         ]
 
+    # pyre-fixme[56]: Pyre was not able to infer the type of the decorator
+    #  `pytest.mark.asyncio`.
     @pytest.mark.asyncio
     @mock.patch(
         "leetcode_anki.helpers.leetcode.LeetcodeData._get_problems_count",
         mock.Mock(return_value=234),
     )
     @mock.patch("leetcode_anki.helpers.leetcode.LeetcodeData._get_problems_data_page")
-    async def test_get_problems_data(self, mock_get_problems_data_page) -> None:
-        question_list = [QUESTION_DETAIL] * 234
+    async def test_get_problems_data(
+        self, mock_get_problems_data_page: mock.Mock
+    ) -> None:
+        question_list: List[
+            leetcode.models.graphql_question_detail.GraphqlQuestionDetail
+        ] = [QUESTION_DETAIL] * 234
 
         def dummy(
             offset: int, page_size: int, page: int