System design for distributed services (APIs, service boundaries, data ownership)
Cloud fundamentals (deploying, scaling, networking basics)
Reliability engineering mindset (monitoring, incident response, root-cause analysis)
Strong coding skills in a backend language (e.g., Java/Kotlin, Go, C#, Python, Node.js)
Databases and data modeling (SQL and at least one NoSQL pattern)
Messaging and async processing (queues/streams, eventual consistency)
Security basics (auth, permissions, secrets handling, secure APIs)
Test strategy (unit/integration/contract tests) and CI/CD practices
Leadership: mentorship, feedback, decision-making, and prioritization
Cross-team communication and stakeholder management