Debugs efficiently and proposes solutions

Communicates design decisions clearly

Ability to own modules

Everything in Level 1 +

Solves unfamiliar problems independently

Challenges product assumptions with data

Capable of clearly documenting code

Everything in Level 2 +

Can manage large teams

Drives architectural consistency

Facilitates cross-team discussions

Everything in Level 3 +

Fractional CTO

Know how of compliance standards (SOC-2, ISO-27001 etc.)

Penetration testing