Blog | Kapil Dagur

4 posts2 topics66 min of reading

Notes on backend engineering, Python tooling and the systems I work with.

```
{
  "name": "My Python App",
  "image": "mcr.microsoft.com/devcontainers/python:3.12",
  "forwardPorts": [8000],
  "postCreateCommand": "pip install --user -r requirements.txt"
}
```
01 LatestTooling · 20 min Dev Containers: your entire dev environment in a single JSON file How devcontainer.json packages tools, runtimes and editor settings so every developer works in the same environment. 15 Apr 2026
```
def greet(name: str) -> str:
    return "Hello, " + name

greet(42)  # error: Argument 1 has
           # incompatible type "int"
```
02 Python · 21 min mypy: make Python's type hints actually do something Static type checking in Python, from the first annotation to strict mode. 15 Mar 2026
```
@pytest.fixture
def sample_user():
    return {"name": "Alice"}

def test_name(sample_user):
    assert sample_user["name"] == "Alice"
```
03 Python · 15 min pytest: the Python testing framework that makes you want to write tests Fixtures, parametrize, mocking and plugins, with what changed in pytest 9.0. 7 Mar 2026
```
$ uv init my-app
$ uv add fastapi uvicorn
$ uv run uvicorn main:app --reload
```
04 Python · 10 min Meet uv: one tool for Python packages, versions and projects How uv replaces pip, pyenv, virtualenv, pipx and Poetry with a single fast binary. 24 Feb 2026