A Big-Four audit firm rebuilt its controls-testing practice on xyner — replacing quarterly sampling with continuous monitoring of 240 client environments and cutting audit cycle costs by 38%.
A Big-4 controls-testing practice was running annual client attestations with armies of staff doing sample-based testing. Practitioners burned out; controls failures were found at year-end; clients were frustrated by the engagement cycle. The practice needed to scale to continuous controls testing without scaling headcount.
Deployed a Controls-Testing Agent on xyner with multi-tenant isolation per client, integration to client systems via secure connectors, and audit-grade evidence capture per control test.
Controls testing shifted from annual sample-based to continuous comprehensive; practitioner satisfaction up materially; engagement margins improved; client findings surface in days, not months; audit-prep time reduced by 75% for participating clients.
A Big-4 audit and advisory firm's controls-testing practice
Continuous controls testing for client engagements across SOC 2, ISO 27001, SOX, GDPR, HIPAA
From contract signature to full rollout.
Multi-tenant by design — each client engagement is fully isolated, with its own data plane scope, its own controls library and its own evidence store. The audit firm's practice manages all engagements from a shared control plane, with per-engagement RBAC and per-client audit boundaries.
Per-engagement specialist; runs control tests against the client's live systems on a defined cadence (daily, weekly, on-event); captures evidence with timestamp and source hash.
Pre-built controls for SOC 2, ISO 27001, SOX, GDPR, HIPAA, plus engagement-specific custom controls. Each control test is defined as a machine-readable specification.
Each client engagement has its own data plane scope; client data is never visible across engagements; the audit firm's practice management never sees client raw data.
Tamper-evident per-engagement evidence store; evidence is indexed by control, framework, period and test execution.
Audit-firm practitioners review aggregated findings, drill into exceptions, and produce client-facing reports — without re-doing the testing work.
Clients see their own posture (read-only) at any time; surprises at audit time become rare.
A 12-week pilot covered three willing client engagements before the practice opened it to the broader client base, with engagement-by-engagement opt-in.
Design and deploy the multi-tenant architecture; complete the firm's security review; establish per-client isolation guarantees.
Build the initial controls library covering the most-used frameworks; complete first peer review of control definitions.
Live with three pilot clients; practitioners review findings; client satisfaction reviewed weekly.
Train the practice; open to additional client engagements opt-in by client.
Add additional frameworks; launch as a premium continuous-controls offering; calibrate practitioner workload allocation.
An audit firm has unique governance constraints — independence, client-data protection, peer review, professional standards. The deployment respects every one of them.
The platform does not perform attestation; practitioners do. The platform produces evidence; practitioners produce opinion. Independence rules respected.
Client data is fully isolated per engagement; cross-engagement data flows are prohibited at the platform level, not just by policy.
Every control test is reproducible; every finding is traceable to the underlying evidence; peer reviewers can re-run any test.
The deployment was reviewed for alignment with relevant professional standards before launch.
The firm's own internal audit function reviews the deployment quarterly with full read access to the platform's audit trail.
Three lessons for other professional-services firms considering platform-based service delivery.
Controls testing was the right starting point because the value of continuous is obvious. Pick service lines where the unit of value naturally compounds with continuous delivery.
Real multi-tenant isolation — not just logical separation — requires architectural rigour. Cutting corners here is the fastest way to lose client trust.
The practitioners had to want this. The pilot included senior practitioners as design partners from week one; the rollout went smoothly because the practitioners owned the change.
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