When Ecommerce Systems Aren't Optimised Your Revenue Is Paying the Price
Frontend Optimisation Only Scratches the Surface
Your frontend team has already done everything they can. Images are compressed, scripts are minified, caching is configured. The easy wins are gone. But product pages are still sluggish, inventory counts don't match, and your team is spending hours on manual workarounds. These problems share a common root: the integration layer between your storefront and your backend systems wasn't engineered for the complexity your business runs on today.
Site Speed Is a Backend Problem
Every product page triggers multiple API calls behind the scenes: checking inventory across warehouses, pulling customer-specific pricing from your ERP, fetching personalisation data from your CDP. If those calls are synchronous, unoptimised, or hitting overloaded endpoints, they add hundreds of milliseconds to every page load. A peer-reviewed Deloitte study found that a 0.1-second improvement in site speed produced an 8.4% increase in conversions and a 9.2% increase in average order value.
Inventory That Doesn't Match
A Fluent Commerce survey found that 58% of retailers maintain inventory accuracy below 80%, meaning stock data is wrong one time in five. Only the top 7% update inventory across channels every five minutes or less. In a high-velocity retail environment where the same SKU is sold through a physical store, a website, and a marketplace, an hour of sync lag creates a large window for overselling, cancelled orders, and customers who don't come back.
Manual Workarounds Everywhere
Reconciling data between disconnected systems. Manually routing orders. Updating stock levels by hand. Each workaround introduces delays that show up as customer-facing problems: delayed order confirmations, incorrect availability, and inconsistent pricing across channels. Every hour your team spends on manual processes is an hour not spent on growth.
Personalisation Without Clean Data
A CDP that can't pull real-time transactional data from your POS, browsing behaviour from your storefront, and loyalty status from your CRM is generating recommendations based on fragments. McKinsey estimates that well-integrated personalisation delivers 5–15% revenue increases. Poorly integrated personalisation delivers noise.
The numbers behind the problem.
The connection between integration quality and ecommerce revenue is well-documented. These are the data points that matter most for retailers running complex, multi-system stacks.
A 0.1-second improvement in site speed produced an 8.4% increase in conversion rate and a 9.2% increase in average order value. For retailers who've already optimised the frontend, the remaining speed gains lie in the backend.
Deloitte, "Milliseconds Make Millions"Vodafone improved its LCP score by 31% through backend work and saw 15% better lead-to-visit rate and 8% more sales. Rakuten 24 achieved a 53% increase in revenue per visitor through similar work.
Estimated annual retail sales lost to stockouts globally. 69% of online shoppers will abandon and buy from a competitor if an item is unavailable. Real-time inventory integration reports 35% improvements in stock accuracy.
Aggregated industry research; Fluent Commerce58% of retailers maintain inventory accuracy below 80%. Only 7% send updates every five minutes or less.
Of consumers will abandon a transaction entirely when their preferred payment method isn't available. Adding BNPL options produced up to 14% revenue increase, with two-thirds from net-new sales.
Worldpay; Stripe A/B test (150,000+ sessions)Revenue increase from well-integrated personalisation, plus 10–30% improvement in marketing-spend efficiency. But gains depend entirely on integration quality between the personalisation engine and your data sources.
McKinsey (independent research)Lucky Brand discovered 1.5 million previously unknown customers when they unified 12.7 million records scattered across four data silos.
Fontis Engineers the Connections That Make Your Stack Work
Fontis is a team of ecommerce engineers who specialise in backend integration for mid-market and enterprise retailers. We work in the layer between your storefront and everything else: ERP, WMS, POS, CDP, OMS, PIM, payment providers, and fulfilment systems. We design, build, and maintain the integrations that keep data flowing accurately and fast across your entire commerce stack.
Vendor-Agnostic
We don't take commissions from platform providers, and we don't recommend tools based on partnerships. We use what works for your business, your systems, and your data flows.
Deep Backend Expertise
We're the engineers other agencies call when their solutions fall short. Our team has solved integration problems at every level of complexity, across every kind of commerce stack: composable, headless, monolithic, legacy, and hybrid.
No Lock-In
We build on open standards, not proprietary frameworks that tie your systems to us or any other single vendor. The goal is technology that serves your business long-term rather than solutions that hold it hostage.
Specialist Depth, Project-Based
Hiring and retaining senior integration engineers full-time is expensive and difficult. Working with Fontis gives you access to deep, specialised expertise for the projects that need it, without the recruitment, onboarding, and ongoing overhead of permanent headcount.
Discovery Call
A 30-minute pre-engagement conversation where we learn about your commerce stack, your pain points, and what you're trying to achieve. No sales pitch. We ask questions, listen, and tell you honestly whether we think we can help.
Integration Audit
We review your current integration architecture: how your systems are connected, where data is flowing (and where it isn't), and where performance, accuracy, or efficiency is being lost. You get a clear picture of what's working, what's costing you, and where the highest-impact improvements sit.
Engineered Solution
We design and build the integrations your business needs. Custom, clean, and built for your specific systems, data flows, and business logic. We handle the build, the testing, and the production rollout. We provide ongoing support because integrations aren't a build-and-forget deliverable.
Concerns We Hear Often
Straight answers to the concerns that come up most when retailers consider working with a specialist integration agency.
Our integrations work fine.
"Fine" often means "we've adapted to it." Manual reconciliation becomes routine. Inventory drift gets corrected at end of day. Slower-than-expected page loads get accepted as normal. These workarounds become invisible over time ... until an audit makes the cost visible. If your team is spending hours on manual processes, if stock counts drift between channels, or if load times lag behind what your frontend work suggests they should, there's recoverable performance in the integration layer. An audit shows you what's there and what it's worth addressing. No commitment required beyond a 30-minute conversation.
This sounds expensive.
The cost of the status quo is already showing up, in your conversion rate, your operational overhead, and the time your team spends on workarounds that have become routine. The question isn't whether integration work is expensive; it's whether the problems it solves cost you more than fixing them does. Not all integration work is a wholesale rebuild. Some of the highest-impact fixes are targeted and surgical. The discovery call and audit tell you what you actually have and what scope of work the problem warrants before you commit to anything.
We don't want to disrupt what's running.
We take continuity seriously. Every engagement begins with a thorough assessment of your current integration architecture before we recommend any changes. The right path forward depends on what that assessment reveals. Some improvements are targeted and surgical, others require more significant architectural work. Either way, we scope changes carefully, communicate clearly about what's involved, and plan production rollouts to minimise disruption.
We already have a development agency.
Many of our clients have existing development relationships. Backend integration sits in a different layer than frontend builds, platform configuration, and UX work - it's the middleware, API orchestration, and data mapping that connects your systems together. Fontis brings specialist depth at that layer. How we engage depends on what your business actually needs.
Can't We Just Use Pre-Built Connectors?
For simple scenarios pre-built iPaaS connectors can work well. But when your stack involves legacy systems, complex fulfilment logic, multi-channel inventory, or non-standard data flows, those connectors hit their limits. If your retail operations are complex, your integrations need to be engineered for that complexity.
Multi-System Complexity
When inventory data needs to flow between an ERP, WMS, POS, ecommerce platform, and marketplace channels with business-specific logic like allocation rules, regional stock buffers, or channel-specific pricing, pre-built connectors rarely handle the full picture.
Legacy System Integration
When the backend uses EDI, flat files, or proprietary APIs that off-the-shelf connectors don't support, custom integration is the only path that works reliably in production.
Peak Performance Requirements
Pre-built connectors may throttle or fail during sale event traffic spikes. Custom integrations can be optimised for specific throughput requirements and tested under load before peak trading.
Business-Specific Order Routing
Ship-from-store, click-and-collect with real-time availability checks, or customer-tier pricing all require custom middleware logic that no pre-built connector provides out of the box.
Your Integrations Should Work as Hard as Your Team Does
Get Started Your Integrations Should Work as Hard as Your Team Does
If slow page loads, inventory discrepancies, checkout friction, or disconnected customer data are holding your conversion rate back, we can help you find where the drag is and build the systems that remove it. 30 minutes. No commitment.