68 challenges across eight tiers. Tier 8 is a warm-up; tier 1 will take an evening. Nothing is locked — play them in any order.
Star out everything after the sk_live_ prefix, however long the key is, leaving other text untouched.
Insert commas as thousands separators: 1234567 becomes 1,234,567.
Squash every run of the same repeated character down to one of it.
Rewrite a log line "DATE TIME LEVEL MESSAGE" as "[LEVEL] MESSAGE (TIME on DATE)".
Turn "Ada Lovelace" into "Lovelace, Ada".
Rewrite every DD/MM/YYYY date as YYYY-MM-DD, leaving the rest of the text alone.
Collapse every run of whitespace down to a single space.
Remove the thousands separators from a number: 1,234,567.89 becomes 1234567.89.
Turn snake_case into kebab-case: user_first_name becomes user-first-name.