Reasons your baby is waking when you put them down
Let's talk about the transition from arms to cot. Why is it that whenever I transfer, my baby always wakes?

Disrupted Sleep Cycles
Babies, like adults, have sleep cycles involving different sleep stages. Babies, in fact, spend a lot more time in lighter-phase sleep. When transferred to the cot, they may experience partial arousal as they transition between sleep cycles, often causing them to wake up fully?
Change in Environment
Babies are sensitive to environmental changes; it's a safety thing. Moving little ones during their sleep can be alarming, too; this will cause them to wake up and search for the familiar they just had?
Lack of Sleep Association
Some babies rely on external sleep associations to fall asleep, such as being held or rocked. When transferred to the cot, they may struggle to recreate these associations or feel they cannot drift back to sleep without the association, leading to wakefulness.
There is another way, though!

Ideas to help the transition from your arms to cot
When you pop your babe into their sleep space, stay close. This might mean leaning into their cot or bassinet so they sense you are near when you first put them in offering a consistent hush and hand on them.
You may also need to pick your babe back up and settle them in your arms, then pop the bub back down again. Perhaps you need to hold them a little longer so they can get into a deeper sleep before you make the move.
I would keep the room where you are trying dark so that if they open their eyes, you are more likely to achieve a resettling rather than a "hello world" at that point.
If they are in the newborn stage, popping them into their Sleeping Bag, Cocoon, etc, before you may the transfer can help them from startling as you move them. If they are older, put your babe into a sleeping bag first.
Their awake times matter. It is best not to let them get too overtired and worked up before you make this transition.

For some, making the move in the first few minutes is better, but for many, waiting 10-15 minutes is best before transferring.
At The Gentle Sleep Specialist, we find that little ones sleep well when they can fall asleep in their sleep space. So, the ability to pop your little one down awake and know they will be able to drift off to sleep and learn how to re-settle when they awaken. As It is when your little ones fall asleep, it will be what they expect when they awaken.
We are always here to help you step by step through this transition.
The Gentle Sleep Specialist x
About the author
Tara Mitchell is a former paediatric nurse of 15 years and is now a leading Sleep Consultant, helping families through the challenges of sleep. Struggling with her own personal experience with a sleepless child, Tara began the Gentle Sleep Specialist to help other parents on their sleep journey.
Website: www.gentlesleep.com.au
Instagram: @thegentlesleepspecialist