Addressing Performance Variability in SASE Deployments

When organisations embark on the journey to adopt Secure Access Service Edge (SASE), performance is typically high on the list of expected benefits. The vision is clear: a seamless user experience across regions, consistent security without bottlenecks, and high availability for hybrid and remote users alike.

But as with many transformations, reality can fall short of expectations.

As deployments scale, leaders often encounter performance variability — differences in speed, reliability, or availability that can affect users, regions, or services in inconsistent and unpredictable ways. These challenges are often subtle but disruptive, impacting trust, adoption, and business continuity.

In this post, we explore why performance variability happens in SASE environments, what it means for business and IT leaders, and how to proactively address it without compromising the core principles of the SASE model.

The Performance Promise of SASE

SASE aims to eliminate the old trade-offs between security and performance by combining networking and security in the cloud — ideally delivered close to users, at scale, and with built-in optimisations.

Some of the core benefits include:

  • Reduced backhauling of traffic to data centres
  • Local breakout and routing to SaaS/IaaS
  • Optimised paths using SD-WAN capabilities
  • Edge-delivered security enforcement (e.g. Zero Trust, threat protection)

In theory, this should improve latency, availability, and user experience, especially for remote and globally distributed teams.

But in practice, many organisations encounter inconsistencies — and resolving them is rarely just a technical matter.

Where Performance Variability Comes From

Even the most modern SASE solutions can suffer from performance hiccups. The causes are often a combination of infrastructure, architecture, and operational maturity.

Common causes include:

  • Geographical coverage gaps in Points of Presence (PoPs) or service nodes
  • Overloaded or congested PoPs during regional demand spikes
  • Inefficient routing decisions, especially across different ISPs or SD-WAN paths
  • Inconsistent last-mile connectivity (e.g. home broadband, mobile hotspots)
  • Traffic inspection bottlenecks, particularly under strict security policies (SSL decryption, DLP, malware scanning)
  • Latency-sensitive applications that don’t tolerate proxy or relay architectures
  • Misconfigured identity-based policies that introduce delays or require repeated authentications

Performance variability doesn’t always show up as downtime — it’s often experienced as sluggishness, lag, or unpredictable failures, which are harder to diagnose but just as damaging.

Business Impact: Why Leaders Should Care

From a leadership perspective, performance variability in SASE isn’t just a technical nuisance — it’s a business risk. The consequences ripple across operations and strategy:

1. User Frustration and Lost Productivity

If users experience lag, blocked access, or frequent reauthentication, trust in the platform drops — and workarounds (e.g. shadow IT, personal hotspots) emerge.

2. Inconsistent Service Delivery

Hybrid work, global teams, and cloud-first strategies depend on predictable performance. Variability introduces risk into critical operations, from customer service to financial trading.

3. Failed ROI Realisation

If performance issues persist, the perceived value of the SASE investment declines. Business units may push for exceptions or rollback to legacy infrastructure.

4. Support Burden

Performance complaints often land with IT, even if the root cause is elsewhere (e.g. ISP latency, cloud service issues), increasing operational load and slowing response.

How to Tackle Performance Variability in SASE

Solving for performance is not about reverting to traditional architectures — it’s about designing and operating SASE with resilience, visibility, and user experience in mind.

Here’s how leadership teams can stay ahead of performance issues.

1. Choose SASE Architectures That Prioritise Local Performance

Not all SASE providers are created equal. While we won’t name vendors here, you should assess the following during selection:

  • Number and distribution of PoPs relative to your user base
  • Ability to steer traffic based on performance, not just policy
  • Optimisation capabilities for SaaS/IaaS (e.g. direct peering, smart routing)
  • Support for regional regulatory requirements (e.g. data sovereignty) without degrading performance

Leadership tip: Don’t just ask about global coverage — ask for empirical latency and throughput metrics from the locations that matter most to your business.

2. Invest in Performance Monitoring and Observability

You can’t manage what you can’t see. Leaders should ensure their teams have access to:

  • Real-time metrics on latency, jitter, and packet loss across SASE components
  • End-to-end visibility from user device to application
  • Alerts for degradation before users report issues
  • Historical data for root cause analysis and capacity planning

Leadership tip: Prioritise platforms that provide a “single pane of glass” for performance, security, and user experience — not separate silos.

3. Optimise Last-Mile Connectivity

While SASE controls much of the data path, the last mile — between the user and the first PoP — can be a major source of variability.

Strategies include:

  • Deploying lightweight edge clients or mobile gateways with intelligent failover
  • Working with ISPs to improve peering or routing paths
  • Educating users on optimising their home/remote environments
  • Offering fallback options (e.g. split tunnelling for trusted apps) when appropriate

Leadership tip: Set realistic expectations — not all problems are fixable in the cloud. Some require user-side or ISP-side adjustments.

4. Align Policy Enforcement with Performance Considerations

Excessively aggressive security controls can degrade performance, especially if they’re layered or duplicated. Review policies for:

  • Redundant scanning (e.g. at both device and cloud level)
  • Overuse of full SSL decryption where not needed
  • Blocking of Content Delivery Networks (CDNs) that serve legitimate SaaS content

Leadership tip: Involve both security and performance teams in policy design — compromise may be necessary to balance protection with usability.

5. Design for Resilience and Failover

Even the best PoPs or providers can experience issues. Your architecture should support:

  • Automatic failover between PoPs or links
  • Dynamic path selection based on real-time conditions
  • Cloud-based redundancy that mirrors traditional high availability principles

Leadership tip: Make performance part of your SASE governance model — test failover paths regularly and measure their real-world impact.

Measuring Success: What Good Looks Like

  • Consistent user experience across regions and devices
  • Fewer support tickets related to connectivity or application slowness
  • Predictable application performance — even under load or during maintenance
  • Reduced reliance on exceptions or fallback methods
  • Improved satisfaction and trust in IT services

Conclusion: Performance is a Business Issue, Not Just a Technical One

SASE is meant to simplify and enhance how users connect securely to business resources — but without consistent performance, that promise falls apart.

Performance variability isn’t a reason to abandon SASE. It’s a signal that your architecture, governance, and operational model need tuning. Leaders who take a proactive, outcome-focused approach can deliver a secure, scalable, and performant SASE environment that truly empowers the business.

If your SASE deployment delivers great security but inconsistent performance, you haven’t failed — you’ve found the next step on the journey.