I was contacted by the recruiter, and two rounds of technical phone screenings were provided. In both rounds, I solved all the problems within the given time.

However, two days after the second phone screening, I received a rejection letter stating that the position had been filled by another candidate with a "stronger match".

The recruiter was professional and astute, but also sounded indifferent towards me, appearing focused solely on completing her job efficiently. The technical interviewers during both screenings were smart and kind.

However, the overall experience was unpleasant for me, as I never understood what I did wrong. Everything seemed to be going smoothly until I received a "punch in the face".

How do you implement a spell correction system?