25 Interview Questions You should know when giving Senior PHP Developer Interview ?
1 ) What is opcache ?
2) What is PHP FPM ?
3) How PHP works Internally ?
4) What is life cycle of HTTP request ?
5) What is Singleton Design pattern ?
6 ) How Indexing Works in mysql in Detail ?
7 ) What is BTREE in index ?
8 ) What is Docker ?
9 ) What is difference between Inner and Left join ?
10 ) What is Memcache ?
11) There is page in your website running slow. How would you detect the problem and solve it?
12 ) What is multi column index ?
13 ) What are SOLID Principle in detail with Example ?
14 ) How to improve your legacy Software ?
15 ) What is EXPLAIN keyword use for in mysql ?
16 ) Write a query to find 3rd Largest Salary ?
17) How to fetch values from TestTable1 that are not in TestTable2 without using NOT keyword ?
SELECT * FROM TestTable1left join TestTable2 on TestTable1.order_num = TestTable2.order_numwhere TestTable2.order_num is null
18) What is the command used to fetch the first 5 characters of a string?
SUBSTRING(column_name , 1 ,5 )
19) What is namespace in PHP ?
20 ) Why we use traits ?
21 ) What is JIT ?
22 ) What are new features of PHP 7 and PHP 8 ?
23 ) How can we prevent SQL-injection in PHP?
24 ) Difference between UNION VS UNION ALL ?
25 ) Are objects in PHP 5 passed by value or reference ?