Deployment Strategies
Rolling, blue-green, canary and shadow, and the traffic and state each one assumes.
4 to work through
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advanced
A deployment reaches seven of eight servers. The eighth runs old code that a reused flag activates. Losses accumulate for 45 minutes. What are the findings?
2 min answer -
advanced Multiple choice
A food-delivery platform in the mould of Zomato rolls out a pricing change in nine steps over 90 minutes with a 10-minute bake between steps. Error rate, latency and saturation stay flat the whole time. The defect is a wrong rounding rule that under-charges some orders, and it surfaces the next morning when finance reconciliation runs. Which change makes this class of rollout safe?
3 min answer -
advanced
A platform must deploy a service holding millions of long-lived connections. Which deployment strategy applies, and what capability makes it work?
1 min answer -
advanced
Your organisation releases every two weeks on a train. Teams complain about lead time. Is the train the problem?
2 min answer
4 terms in this topic
Blue-Green Deployment
Two complete production environments where traffic is switched from the old to the new in one step, and back just as fast.
conceptLeading Health Signal
A rollout gate input whose latency is shorter than the damage it indicates - the property that decides whether any bake time can catch a defect, as d…
patternRelease Train
A fixed-cadence release where whatever is ready by the departure time ships, and whatever is not waits for the next one.
conceptRolling Update Surge
The extra capacity a rolling deployment temporarily adds, and the unavailability it is permitted, which together decide whether the rollout is safe u…
Neighbouring topics
Delivery & Release Engineering
General material on getting a change from commit to production safely and often.
Pipeline Architecture
Stages, fan-out, caching, and the difference between a pipeline and a long script.
Build Reproducibility
Pinned inputs and hermetic builds, so one commit cannot produce two different artifacts.
Artifact Management
Immutable versioned outputs, promotion between repositories, and retention policy.
Environment Strategy
How many environments earn their cost, what each proves, and what none of them prove.
Branching Models
GitFlow, trunk and release branches as delivery constraints rather than Git preferences.
Continuous Integration Discipline
Integrating to the mainline daily, and the test speed and review culture that requires.
Progressive Delivery
Separating deploy from release, and exposing a change to users in controlled increments.
Rollback & Forward Fix
When reversing is genuinely possible, and designing so that it usually is.
Database Migration Under CD
Expand-contract, backwards-compatible schema change, and migrations that cannot roll back.
GitOps
Declared desired state in version control, with a reconciler closing the gap continuously.
IaC Modules & Drift
Reusable infrastructure modules, state ownership, and detecting what changed out of band.
Policy as Code
Encoding standards as automated admission and plan-time checks instead of review comments.
Pipeline Secrets
Short-lived credentials, workload identity, and why the CI system is a prime target.
Supply-Chain Provenance
SBOMs, signed artifacts, attestation, and knowing what actually went into a build.
Deployment Gates
Automated verification between stages, and the difference between a gate and a delay.
Flow Metrics
Work in progress, flow time and flow efficiency — where a change waits rather than moves.
Change Management vs CD
Reconciling CAB-era controls with continuous delivery without pretending either away.
Multi-Region Rollout
Ordering regions, bake time, and stopping a bad change before it becomes global.