know (something) backwards and forwards

to be extremely well informed about something.

After 30 years in the fashion business, she knows it backwards and forwards.

He knows New York inside out.

Related vocabulary: know something like the back of your hand

• in the same league as something
• in the scheme of things
• in the shadow of
• in the shadow of someone
• in the shadow of something
• in the short run
• in the short term
• in the soup
• in the strictest confidence
• in the strict sense
• in the teeth of
• in the teeth of something
• in the thick of it
• in the toilet
• in the twinkling of an eye
• in the vicinity of
• in the vicinity of something
• in the wake of
• in the wake of something
• in the way
• in the way of
• in the way of something
• in the wilderness
• in the wind
• in the wings