Technical deep-dives on the bugs that slip past every code review. Async races, Django N+1 queries, type hint traps — and how automated review catches them before production.
Testing the mock not the code, assertion-free tests, expected values that mirror the implementation, probing private details, and parametrize that skips real edge cases — 5 anti-patterns that keep CI green while catching zero real bugs.
mypy says green. Production says otherwise. Optional without None checks, TypedDict at runtime, covariant generics, decorator signature loss, and mutable defaults — the 5 Python typing mistakes that pass the linter and break in prod.
select_related vs prefetch_related, list comprehension N+1, template-level lazy loads, aggregation shortcuts, and DRF serializer queries — the 5 Django N+1 patterns that kill performance silently.
Async/await races, Django ORM N+1 queries, silent exception swallowing — the 5 Python PR bugs that slip past every code review, and how automated review catches them.
5 async, Django, and type hint bugs that ship to production — and the one-line fix for each. No signup required to read, email to download.