ShelCron

DevOps & Cloud

High Availability

Redundancy patterns that keep critical services available through common failures.

High availability engineering for systems that cannot rely on a single host or single point of failure. We design redundancy for compute, data, and traffic layers with explicit failure domains—and we validate failover paths instead of assuming they work.

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Who it’s for

  • Teams running revenue-critical or telephony-critical systems
  • Platform leads reducing single-host risk
  • Companies preparing for stricter uptime expectations

Problems we address

  • Critical services still run as single instances
  • Failover exists on paper but has never been rehearsed
  • Data layer HA was deferred until after an outage

Expected outcomes

  • Redundant service topologies with clear failure domains
  • Health checks and automated or rehearsed failover
  • Data replication patterns matched to consistency needs

Capabilities

Concrete engineering capabilities included in a typical engagement for this service.

HA topology design for apps and data

Multi-AZ or multi-node patterns

Failover testing and game days

Load balancer health check tuning

Documentation of degraded-mode behavior

Technology

Representative technologies used for this service. Final stack depends on your estate.

  • Load balancers
  • Kubernetes
  • Postgres replication
  • Keepalived
  • AWS ALB/NLB
  • DNS failover

Architecture

Delivery pipeline

Source control through CI into containerized deploy and cloud runtime.

GitCIDockerKubernetesCloud

Deliverables

  • HA design for scoped systems
  • Implemented redundancy as agreed
  • Failover test results
  • Operator runbooks for failover and failback

Out of scope

  • Contractual uptime credits from cloud vendors

Timeline

Typical timeline

3–10 weeks

Timeline depends on scope, access, and dependencies—not a delivery guarantee.

Process

A clear delivery path from discovery through handover and optional support.

  1. 01

    Discovery

    Goals, constraints, success criteria, and current-state review.

  2. 02

    Architecture

    Target design, interfaces, risks, and delivery sequence.

  3. 03

    Implementation

    Incremental build with visible progress and documented decisions.

  4. 04

    Testing

    Functional checks, failure paths, and acceptance criteria validation.

  5. 05

    Deployment

    Controlled release to staging and production with rollback paths.

  6. 06

    Handover

    Runbooks, access notes, and operator/admin walkthrough.

  7. 07

    Support

    Optional hypercare window or retainer continuity after go-live.

Custom engagement

Pricing depends on architecture, traffic profile, and integration depth. Share your requirements for a scoped quote.

FAQ

We design toward your availability goals and remove known single points of failure. Published SLA percentages also depend on your cloud provider and operational response.

Depends on data consistency, cost, and traffic shape. We recommend the simplest pattern that meets the availability need.

Ready to build?

Tell us about your environment, constraints, and target outcomes. We’ll recommend a package or a scoped quote.