"Men believe themselves to be free because they are conscious of their actions and ignorant of the causes by which they are determined." (Spinoza, Ethics II, Prop. 35)
Determinism is the fundamental philosophy that underpins my practice.
It provides an answer to guilt, shame, worry, regret and even low self esteem.
Essentially, you (and everyone else) have behaved in exact accordance to your prior conditioning.
Change means that you seek out and expose yourself to corrective experiences. This could be therapy, or exposure to fearful experiences or even daring to be yourself (when you have been conditioned to prioritize the needs of others).
It is these corrective experiences that facilitate (and actually necessitate) personal change.
Prior conditioning leads to the formation of core beliefs and drives. An example of a (negative) core belief is "nobody cares." This core belief will lead to the creation of a subconscious drive to prove the correctness of that core belief.
Let's take an example of a core belief's formation. The father of an 8 year girl leaves the mother and the girl forms the core belief "all men leave." When she grows up and marries, she behaves in a distant, cold and critical manner to her husband. Eventually, he leaves and she can triumphantly say "See, I knew it" (completely unconscious of her inner drive to prove her core belief correct).
Excavating core beliefs and their associated drives is essential to figuring out exactly what needs to be reconditioned.
That is what I do.
"Man's task is to become conscious of the contents that press upward from the unconscious" Carl Jung

I have spent over 20 years in software development. A key part of that involves determining the most efficient algorithm (finding the easiest, most direct means of solving a problem). Since 2007, I have been a practicing therapist. I have used skills and concepts that I learned writing software to refine and systematize my approach to personal change.