JNCIS-DevOps case studies
JNCIS-DevOps · Put your knowledge to work in context.
The Juniper Networks Certified Specialist DevOps credential - commonly written JNCIS-DevOps - is a specialist-level certification aimed at network engineers, automation engineers and platform teams who build and operate Juniper-based networks through software rather than manual CLI work. The published blueprint splits the exam into five equally weighted domains of 20 percent each: DevOps fundamentals and culture; automation and configuration management; continuous integration and continuous delivery; infrastructure as code and network programmability; and monitoring, observability and operations. The JNCIS-DevOps case studies are 5 cases and about 5,075 words.
1Monthly Release Window, 38% Change Failure Rate, and the DBA Shadow Process
Northwind Retail runs 1,200 stores on a monolithic order platform. Releases are batched into a monthly window: code freeze on the 1st, deployment on the 14th, and every change - including a one-line config tweak - must pass the Change Advisory Board, which meets weekly and spends about 40 minutes per release.
960 words, about 5 min2Always-Changed Ansible Playbooks on 64 Junos Devices
A regional ISP manages 64 Junos devices (48 MX/ACX routers, 16 EX switches) with a repository of 11 Ansible playbooks. Nearly every task uses cli command or cli config with hand-built set commands, because that is what the original author knew.
998 words, about 5 min3A 38-Minute Pipeline, a 24% Flaky Suite, and Coupled Rollback
A payments company deploys a Java service and its Terraform-managed cloud environment from one Jenkins pipeline. A full build takes 38 minutes, of which 22 minutes is an integration suite that fails about 24% of runs for reasons unrelated to the code under test.
1,029 words, about 5 min4Out-of-Band Firewall Rule, Unlocked State, and Two Concurrent Applies
Terraform manages VLAN, prefix, and firewall-policy intent for three data centers through a provider that writes to a network controller's REST API. State lives in an S3 bucket with no lock table.
977 words, about 5 min51,400 Alerts a Week, 3% Actionable, and a Customer-Reported Routing Loop
A managed-services provider monitors 210 customer edge devices with SNMP polling every 5 minutes plus syslog. The on-call rotation receives about 1,400 alerts per week across 12 people.
1,111 words, about 6 min