Lessons learned debugging ML models:

1/ It pays to be paranoid. Bugs can take so long to find that it’s best to be really careful as you go. Add breakpoints to sanity check numpy tensors while you're coding; add visualizations just before your forward pass (it must be right before! otherwise errors will slip in).
2/ It's not enough to be paranoid about code. The majority of issues are actually with the dataset. If you're lucky, the issue is so flagrant that you know something must be wrong after model training or evaluation. But most of the time you won't even notice.
3/ The antidote is obsessive data paranoia. Without this, data issues will silently take away a few percentage points of model accuracy.
4/ You can unit test ML models, but it's different from unit testing code. To prevent bugs from re-occurring, you have to curate scenarios of interest, then turn them into many small test sets ("unit tests") instead of one large one.
5/ Each unit test should have an evaluation metric of interest, a pass/fail threshold, and be defined for a curated subset of data.
6/ Without model unit tests, you will see aggregate metrics improving in your evaluation but introduce critical regressions when you actually ship the model. Unit tests are a requirement to durably fix bugs in ML-powered products.
7/ Bugs are fixed faster when iteration times are faster. Impose a hard ceiling on model training time, even if you could squeeze more gain by training a bit longer. In the long run, experiment velocity >> performance of one model.

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🌿𝑻𝒉𝒆 𝒔𝒕𝒐𝒓𝒚 𝒐𝒇 𝒂 𝑺𝒕𝒂𝒓 : 𝑫𝒉𝒓𝒖𝒗𝒂 & 𝑽𝒊𝒔𝒉𝒏𝒖

Once upon a time there was a Raja named Uttānapāda born of Svayambhuva Manu,1st man on earth.He had 2 beautiful wives - Suniti & Suruchi & two sons were born of them Dhruva & Uttama respectively.
#talesofkrishna https://t.co/E85MTPkF9W


Now Suniti was the daughter of a tribal chief while Suruchi was the daughter of a rich king. Hence Suruchi was always favored the most by Raja while Suniti was ignored. But while Suniti was gentle & kind hearted by nature Suruchi was venomous inside.
#KrishnaLeela


The story is of a time when ideally the eldest son of the king becomes the heir to the throne. Hence the sinhasan of the Raja belonged to Dhruva.This is why Suruchi who was the 2nd wife nourished poison in her heart for Dhruva as she knew her son will never get the throne.


One day when Dhruva was just 5 years old he went on to sit on his father's lap. Suruchi, the jealous queen, got enraged and shoved him away from Raja as she never wanted Raja to shower Dhruva with his fatherly affection.


Dhruva protested questioning his step mother "why can't i sit on my own father's lap?" A furious Suruchi berated him saying "only God can allow him that privilege. Go ask him"