diff --git a/arctic_training/checkpoint/ds_engine.py b/arctic_training/checkpoint/ds_engine.py
index 6d2f4ba..edd906e 100644
--- a/arctic_training/checkpoint/ds_engine.py
+++ b/arctic_training/checkpoint/ds_engine.py
@@ -39,13 +39,15 @@ def checkpoint_tag(self) -> str:
 
     @property
     def client_state(self) -> Dict[str, Any]:
-        return {
+        state = {
             "end_of_epoch": self.trainer.epoch_idx,
             "torch_random_state": torch.get_rng_state(),
-            "torch_cuda_random_state": torch.cuda.get_rng_state(),
             "np_random_state": np.random.get_state(),
             "python_random_state": random.getstate(),
         }
+        if self.device != torch.device("cpu"):
+            state["torch_cuda_random_state"] = torch.cuda.get_rng_state()
+        return state
 
     def save(self, model) -> None:
         model.save_checkpoint(
@@ -59,9 +61,10 @@ def load(self, model) -> None:
             return
         _, client_states = model.load_checkpoint(self.checkpoint_dir)
 
-        self.trainer.global_step = model.global_step
+        self.trainer.global_step = model.global_steps
         self.trainer.epoch_idx = client_states["end_of_epoch"] + 1
         torch.set_rng_state(client_states["torch_random_state"])
-        torch.cuda.set_rng_state(client_states["torch_cuda_random_state"])
         np.random.set_state(client_states["np_random_state"])
         random.setstate(client_states["python_random_state"])
+        if self.device != torch.device("cpu"):
+            torch.cuda.set_rng_state(client_states["torch_cuda_random_state"])
diff --git a/arctic_training/cli.py b/arctic_training/cli.py
index dad3a04..abd1115 100644
--- a/arctic_training/cli.py
+++ b/arctic_training/cli.py
@@ -46,6 +46,8 @@ def main():
 
 
 def run_script():
+    import deepspeed.comm as dist
+
     from arctic_training.config.trainer import get_config
 
     parser = argparse.ArgumentParser()
@@ -69,3 +71,6 @@ def run_script():
     config = get_config(args.config)
     trainer = config.trainer
     trainer.train()
+    if dist.is_initialized():
+        dist.barrier()
+        dist.destroy_process_group()
diff --git a/arctic_training/config/trainer.py b/arctic_training/config/trainer.py
index b16a522..63e897a 100644
--- a/arctic_training/config/trainer.py
+++ b/arctic_training/config/trainer.py
@@ -281,11 +281,14 @@ def validate_single_checkpoint_resume(self) -> Self:
         return self
 
 
-def get_config(config_file: Path) -> BaseConfig:
-    with open(config_file, "r") as f:
-        config_dict = yaml.safe_load(f)
-
-    config_dir = config_file.parent
+def get_config(config_file_or_dict: Union[Path, Dict]) -> BaseConfig:
+    if isinstance(config_file_or_dict, dict):
+        config_dict = config_file_or_dict
+        config_dir = Path.cwd()
+    else:
+        with open(config_file_or_dict, "r") as f:
+            config_dict = yaml.safe_load(f)
+        config_dir = config_file_or_dict.parent
 
     trainer_type = config_dict.get("type", TRAINER_DEFAULT)
     config_dict["type"] = trainer_type
diff --git a/arctic_training/data/factory.py b/arctic_training/data/factory.py
index 241da41..3662dee 100644
--- a/arctic_training/data/factory.py
+++ b/arctic_training/data/factory.py
@@ -52,7 +52,7 @@ class DataFactory(ABC, CallbackMixin):
     specify the DataFactory to use.
     """
 
-    config_type: Type[DataConfig]
+    config_type: Type[DataConfig] = DataConfig
     """
     The type of the DataConfig object that this DataFactory uses. Any
     DataFactory-specific options should be specified in this class.
diff --git a/arctic_training/trainer/trainer.py b/arctic_training/trainer/trainer.py
index cd6e4a2..e1bfc4d 100644
--- a/arctic_training/trainer/trainer.py
+++ b/arctic_training/trainer/trainer.py
@@ -159,6 +159,10 @@ def __init__(self, config: "TrainerConfig") -> None:
             engine(self) for engine in self.config.checkpoint_engines
         ]
 
+        for engine in self.checkpoint_engines:
+            if engine.config.auto_resume:
+                engine.load(self.model)
+
     def _set_seeds(self, seed: int) -> None:
         logger.info(f"Setting random seeds to {seed}")
         torch.manual_seed(seed)
@@ -241,10 +245,8 @@ def step(self, batch: Dict[str, torch.Tensor]) -> None:
             self.config.exit_iteration > 0
             and self.config.exit_iteration == self.global_step
         ):
-            logger.info(f"Hit exit iteration of {self.global_step}, forcing exit")
-            torch.distributed.barrier()
-            torch.distributed.destroy_process_group()
-            exit()
+            self.early_stop = True
+            logger.info(f"Hit exit iteration of {self.global_step}, ending training")
 
     @callback_wrapper("epoch")
     def epoch(self) -> None:
diff --git a/tests/checkpoint/test_ds_engine.py b/tests/checkpoint/test_ds_engine.py
new file mode 100644
index 0000000..2d5c03b
--- /dev/null
+++ b/tests/checkpoint/test_ds_engine.py
@@ -0,0 +1,52 @@
+import pytest
+from utils import models_are_equal
+
+from arctic_training.config.trainer import get_config
+
+
+@pytest.mark.cpu
+def test_ds_engine(tmp_path):
+    config_dict = {
+        "type": "sft",
+        "exit_iteration": 2,
+        "model": {
+            "type": "random-weight-hf",
+            "name_or_path": "HuggingFaceTB/SmolLM-135M-Instruct",
+            "attn_implementation": "eager",
+            "dtype": "float32",
+        },
+        "data": {
+            "type": "noop",
+            "sources": [],
+        },
+        "optimizer": {
+            "type": "cpu-adam",
+        },
+        "scheduler": {
+            "type": "noop",
+        },
+        "checkpoint": {
+            "type": "deepspeed",
+            "auto_resume": True,
+            "output_dir": str(tmp_path / "checkpoints"),
+            "save_end_of_training": True,
+        },
+    }
+
+    config = get_config(config_dict)
+    trainer = config.trainer
+
+    # Force checkpoint to be saved despite no training happening
+    trainer.training_finished = True
+    trainer.checkpoint()
+
+    # Store original model for comparison later
+    original_model = trainer.model
+
+    config_dict["seed"] = 0  # Make sure newly initialized model is different
+    config = get_config(config_dict)
+    trainer = config.trainer
+
+    loaded_model = trainer.model
+    assert models_are_equal(original_model, loaded_model), "Models are not equal"
+    # TODO: Add assertion on optimizer state
diff --git a/tests/checkpoint/test_hf_engine.py b/tests/checkpoint/test_hf_engine.py
new file mode 100644
index 0000000..af50cb6
--- /dev/null
+++ b/tests/checkpoint/test_hf_engine.py
@@ -0,0 +1,51 @@
+import pytest
+from utils import models_are_equal
+
+from arctic_training.config.trainer import get_config
+
+
+@pytest.mark.cpu
+def test_hf_engine(tmp_path):
+    config_dict = {
+        "type": "sft",
+        "model": {
+            "type": "random-weight-hf",
+            "name_or_path": "HuggingFaceTB/SmolLM-135M-Instruct",
+            "attn_implementation": "eager",
+            "dtype": "float32",
+        },
+        "data": {
+            "type": "noop",
+            "sources": [],
+        },
+        "optimizer": {
+            "type": "cpu-adam",
+        },
+        "scheduler": {
+            "type": "noop",
+        },
+        "checkpoint": {
+            "type": "huggingface",
+            "output_dir": str(tmp_path / "checkpoints"),
+            "save_end_of_training": True,
+        },
+    }
+
+    config = get_config(config_dict)
+    trainer = config.trainer
+
+    # Force checkpoint to be saved despite no training happening
+    trainer.training_finished = True
+    trainer.checkpoint()
+
+    # Store original model for comparison later
+    original_model = trainer.model
+
+    config_dict["model"]["name_or_path"] = str(
+        trainer.checkpoint_engines[0].checkpoint_dir
+    )
+    config = get_config(config_dict)
+    trainer = config.trainer
+
+    loaded_model = trainer.model
+    assert models_are_equal(original_model, loaded_model), "Models are not equal"
diff --git a/tests/checkpoint/utils.py b/tests/checkpoint/utils.py
new file mode 100644
index 0000000..8dc1a3e
--- /dev/null
+++ b/tests/checkpoint/utils.py
@@ -0,0 +1,9 @@
+import torch
+
+
+def models_are_equal(model_a: torch.nn.Module, model_b: torch.nn.Module) -> bool:
+    for param_a, param_b in zip(model_a.parameters(), model_b.parameters()):
+        if not param_a.data.eq(param_b.data).all():
+            return False
+
+    return True
diff --git a/tests/conftest.py b/tests/conftest.py
index 3e86bce..d8453a8 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -12,3 +12,68 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
+import os
+
+import pytest
+
+
+def pytest_configure(config):
+    # TODO: Make it so that cpu and gpu tests can be run with a single command.
+    # This requires some work with tearing down/setting up dist environments
+    # that have not been worked out yet.
+    if not config.option.markexpr:
+        config.option.markexpr = "cpu"
+    if "gpu" in config.option.markexpr and "cpu" in config.option.markexpr:
+        pytest.fail("Cannot run tests with both 'gpu' and 'cpu' marks")
+    if "cpu" in config.option.markexpr:
+        _setup_cpu_dist()
+    if "gpu" in config.option.markexpr:
+        _setup_gpu_dist()
+
+
+def _setup_cpu_dist():
+    os.environ["DS_ACCELERATOR"] = "cpu"
+    os.environ["LOCAL_RANK"] = "0"
+    os.environ["RANK"] = "0"
+    os.environ["MASTER_ADDR"] = "127.0.0.1"
+    os.environ["MASTER_PORT"] = "29500"
+    os.environ["WORLD_SIZE"] = "1"
+    os.environ["LOCAL_SIZE"] = "1"
+
+    from deepspeed.comm import init_distributed
+
+    init_distributed(auto_mpi_discovery=False)
+
+
+def _setup_gpu_dist():
+    os.environ["DS_ACCELERATOR"] = "cuda"
+    os.environ["LOCAL_RANK"] = "0"
+    os.environ["RANK"] = "0"
+    os.environ["MASTER_ADDR"] = "127.0.0.1"
+    os.environ["MASTER_PORT"] = "29500"
+    os.environ["WORLD_SIZE"] = "1"
+    os.environ["LOCAL_SIZE"] = "1"
+
+    from deepspeed.comm import init_distributed
+
+    init_distributed(auto_mpi_discovery=False)
+
+
+# Eventually when we can run cpu + gpu tests, we will want to order the tests to
+# avoid thrashing back and forth between the distirbuted environments.
+"""
+@pytest.hookimpl(trylast=True)
+def pytest_collection_modifyitems(config, items):
+    t scpu_tests = [item for item in items if "cpu" in item.keywords]
+    gpu_tests = [item for item in items if "gpu" in item.keywords]
+
+    # Reorder tests: all 'cpu' tests first, then 'gpu' tests
+    items[:] = cpu_tests + gpu_tests
+"""
+
+
+# Load helper functions automatically for all tests
+@pytest.fixture(scope="session", autouse=True)
+def helpers_code_path() -> None:
+    from . import test_helpers  # noqa: F401
diff --git a/tests/trainer/trainer_test_helpers.py b/tests/test_helpers.py
similarity index 69%
rename from tests/trainer/trainer_test_helpers.py
rename to tests/test_helpers.py
index eb9677f..f76f34d 100644
--- a/tests/trainer/trainer_test_helpers.py
+++ b/tests/test_helpers.py
@@ -5,9 +5,12 @@
 from transformers import PreTrainedModel
 
 from arctic_training import register
+from arctic_training.data.factory import DataFactory
 from arctic_training.data.source import DataSource
 from arctic_training.model.hf_factory import HFModelFactory
-from arctic_training.optimizer import FusedAdamOptimizerFactory
+from arctic_training.optimizer.adam_factory import FusedAdamOptimizerFactory
+from arctic_training.optimizer.factory import OptimizerFactory
+from arctic_training.scheduler.factory import SchedulerFactory
 
 
 @register
@@ -52,3 +55,33 @@ def create_optimizer(self, model, optimizer_config):
             lr=optimizer_config.learning_rate,
             betas=optimizer_config.betas,
         )
+
+
+@register
+class NoOpOptimizerFactory(OptimizerFactory):
+    name = "noop"
+
+    def create_optimizer(self, model, optimizer_config):
+        return None
+
+
+@register
+class NoOpDataFactory(DataFactory):
+    name = "noop"
+
+    def __call__(self):
+        return None, None
+
+    def tokenize_fn(self):
+        pass
+
+    def collate_fn(self):
+        pass
+
+
+@register
+class NoOpSchedulerFactory(SchedulerFactory):
+    name = "noop"
+
+    def create_scheduler(self, optimizer):
+        return None
diff --git a/tests/trainer/test_sft_trainer.py b/tests/trainer/test_sft_trainer.py
index 0f6adde..f613105 100644
--- a/tests/trainer/test_sft_trainer.py
+++ b/tests/trainer/test_sft_trainer.py
@@ -1,16 +1,13 @@
-import os
-import subprocess
-from pathlib import Path
-
 import pytest
 import yaml
 
+from arctic_training.config.trainer import get_config
+
 
 @pytest.mark.gpu
 def test_sft_trainer(tmp_path):
     config_dict = {
         "type": "sft",
-        "code": str(Path(__file__).parent / "trainer_test_helpers.py"),
         "exit_iteration": 2,
         "micro_batch_size": 1,
         "model": {
@@ -27,20 +24,16 @@ def test_sft_trainer(tmp_path):
     with open(config_path, "w") as f:
         f.write(yaml.dump(config_dict))
 
-    result = subprocess.run(
-        f"arctic_training {config_path}", shell=True, text=True, capture_output=True
-    )
-
-    if result.returncode != 0:
-        print(result.stderr)
-        pytest.fail("Training failed")
+    config = get_config(config_path)
+    trainer = config.trainer
+    trainer.train()
+    assert trainer.global_step > 0, "Training did not run"
 
 
 @pytest.mark.cpu
 def test_sft_trainer_cpu(tmp_path):
     config_dict = {
         "type": "sft",
-        "code": str(Path(__file__).parent / "trainer_test_helpers.py"),
         "exit_iteration": 2,
         "micro_batch_size": 1,
         "model": {
@@ -66,17 +59,7 @@ def test_sft_trainer_cpu(tmp_path):
     with open(config_path, "w") as f:
         f.write(yaml.dump(config_dict))
 
-    env = os.environ.copy()
-    env["DS_ACCELERATOR"] = "cpu"
-
-    result = subprocess.run(
-        f"arctic_training {config_path}",
-        shell=True,
-        text=True,
-        capture_output=True,
-        env=env,
-    )
-
-    if result.returncode != 0:
-        print(result.stderr)
-        pytest.fail("Training failed")
+    config = get_config(config_path)
+    trainer = config.trainer
+    trainer.train()
+    assert trainer.global_step > 0, "Training did not run"