L2 Support: diagnose, mitigate, and escalate

Objectives and progression

A professional assessment course with six modules on production-support decisions. Interpret Linux, DNS, HTTP, TLS, PostgreSQL, and Kubernetes signals; practice reconciliation before retry, English communication, handover, and improvement. Includes fictional funds and APS scenarios and an internal assessment of 27 decisions in 60 minutes. L2/L3 boundaries and authorizations depend on the organization.

Audience: APS L2/L3, infrastructure, SRE, systems administration teams, and technical managers.

Prerequisites: Application, monitoring, and production-support fundamentals; no bank-specific internal process assumed.

300 estimated study minutes

• Distinguish symptoms, impact, and urgency to organize the response.
• Build a reproducible diagnosis without exposing sensitive data.
• Interpret service, DNS, HTTP, TLS, and resource states.
• Choose controlled actions and demonstrate service recovery.
• Provide actionable context and keep stakeholders informed.
• Maintain continuity and turn incidents into verifiable actions.

Modules

1. Triage based on impact
2. Useful hypotheses and evidence
3. Diagnosis by layer
4. Operational mitigation and validation
5. Escalation and communication in English
6. Handover and improvement

Continue learning

Technical assessments

• Application Production Support
• Incident Management
• Problem Management
• Middleware

References and version

Operational support; PostgreSQL 18, OpenSSL 3.5 and BIND 9.20.29 examples; reviewed 2026-09-30

• Effective troubleshooting · 2026-09-30
• Incident response · 2026-09-30
• Postmortem culture · 2026-09-30
• systemctl manual · 2026-09-30
• journalctl manual · 2026-09-30
• df manual · 2026-09-30
• curl command line manual · 2026-09-30
• openssl s_client · 2026-09-30
• BIND dig manual · 2026-09-30
• Monitoring database activity · 2026-09-30
• Viewing locks · 2026-09-30
• Logging cheat sheet · 2026-09-30
• Pod lifecycle · 2026-09-30
• Debug pods · 2026-09-30
• Timeouts retries and backoff with jitter · 2026-09-30