This interview is for the role of Automation Engineer, but the rounds were quite similar to those of Dev-ops engineer and Embedded Software Engineer.

I applied for an off-campus drive in March 2021. The process involved a technical aptitude test on hackerearth platform. The test had around 39 mcqs on major topics of DSA,OS,CN and Microcontrollers/Microprocessors and one coding question on arrays and subarrays of medium-difficult level. Almost a week later I received a mail for technical round the next day. So there was hardly any timme to brush up the concepts.  Espressif has a really detailed recruitment process. They had 3 technical interviews and 1 HR interview.

The first interview:
This interview was mostly on the projects. Since the company works on embedded systems, they expect us to have knowledge mainly on the scripting languages- Python and C. So java, JavaScript and all don't matter. After a detailed discussion on projects, I was asked puzzles- the 8 identical balls, 1 heavy among them question(you will find it on gfg). After telling the solution, he asked me that how would a 6th grade student using science concepts could identify. (I told him that he could use buoyancy). He was impressed by the reply and asked another puzzle. the 2 ropes question, find 45min (you will find this as well on gfg) and a king and 1000 wines question. Moving on he asked few coding questions, to left shift an array by any index and to invert the cases of a text file. Moving on he asked a few questions on data structures and finished the interview.  Few linux commands. And a code to find the number of ways to reach the top of 25stairs by taking1,2 or three steps at a time.

The second technical interview:
This interview started directly with coding questions: To insert a node in between the linked list, sort the same.(I couldn't sort the list but I told him the pseudocode but he insisted for the code and waits till you write it). Moving on some other python related questions,  to print all the elements of an array in 1 line code(use list comprehension). Difference between arrays and list in python. WHat are tuples. How can you read a file and print all the lines of a file.(use readlines()). What is readlines. Then a few questions on RTOS..Semaphores, mutex, memory management and data structures- malloc/calloc, heap-stack, hashing, sorting and few embedded related questions(not important though). 
I was eliminated after this round.

My interview experience was amazing. The interviewers make the candidate really comfortable. I asked both of them for feedback of the interview and they were really kind to tell my mistakes and I also asked them what exactly do they expect from an automation engineer because I really searched the entire web for some help but there was no review anywhere. So basically automation engineer has to write a few codes on testing, automate any process, remote accessing and stuff.
My suggestion is that apply to this company only if you are interested in the role. The money is good but the work will be enjoyble only if embedded engineering interests you, otherwise it will be frustrating and you will end up leaving the job within a couple of months.
Anyway all the best!! Hope you crack it. :)