The verdict in three sentences
Syncing data in real time between an ERP and a web app costs between 10,000 and 30,000 EUR in 2026, with the event-driven architecture as the main cost driver. Real-time avoids stockouts and oversells but requires message queues, conflict handling and pricier infrastructure; batch stays up to 50% cheaper but tolerates a lag. The right question isn't technical but operational: how much does one hour of wrong data cost you?
Batch vs real-time: the calculation that decides
A logistics director selling the same stock across channels can't afford a lag. But for daily reporting, batch is enough. Here are 2026 ranges for Toronto.
| Approach | Initial cost (EUR) | Timeline | Freshness | Infra/yr |
|---|---|---|---|---|
| Scheduled batch (night/hour) | 8,000 - 14,000 | 4-7 wks | 1-24 h lag | 1,000 - 2,500 |
| Near real-time (polling 1-5 min) | 12,000 - 20,000 | 6-9 wks | < 5 min lag | 2,500 - 5,000 |
| Event-driven real-time | 20,000 - 30,000 | 8-12 wks | Instant | 5,000 - 10,000 |
Event-driven (message queues, ERP webhooks) is the only truly real-time mode, but it often doubles infrastructure cost due to the orchestration and resilience required.
The building blocks of a reliable real-time sync
Real-time is only reliable if it handles failures and conflicts. These blocks are not optional in production.
| Block | Role | Indicative cost (EUR) |
|---|---|---|
| Message queue | Absorb spikes, guarantee delivery | 3,000 - 6,000 |
| Conflict handling | Source priority rule | 2,000 - 4,000 |
| Idempotency & retry | Avoid duplicates | 2,000 - 4,000 |
| Dead-letter & alerting | Handle failures | 1,500 - 3,000 |
| Periodic reconciliation | Safety net | 2,000 - 4,000 |
| Real-time monitoring | Detect drift | 1,500 - 3,000 |
Need a professional website?
Kolonell builds websites that attract clients, optimized for the Sénégalese market. Free quote in 2 minutes.
Mini case study
James, logistics director of a distributor in Toronto (multi-warehouse, web + B2B sales) suffered oversells due to stale stock between ERP and web platform. Cost of an oversell: refund, goodwill gesture, brand impact, estimated at 45 EUR per incident, ~40 incidents/month. We scoped an event-driven sync at 26,000 EUR, 10-week timeline. Losses avoided: 40 x 45 x 12 = 21,600 EUR/yr, excluding the customer-trust gain. Payback in 18 months, infra at 8,000 EUR/yr.
FAQ
Batch or real-time: how to decide? Cost out one hour of wrong data (oversell, stockout, dispute). If that cost is high and frequent, real-time is justified; otherwise batch at 8,000-14,000 EUR is enough and half as expensive to run.
Why does real-time double the infra? Because it needs message queues, redundancy, monitoring and continuous failure handling. Budget 5,000 to 10,000 EUR/yr versus 1,000 to 2,500 for batch.
What is event-driven? An architecture where each ERP change emits an event processed immediately by the app, via a message queue. It is the only truly instant, resilient mode.
How do I handle data conflicts? With a priority rule (ERP is authoritative on stock, app on orders) and a periodic reconciliation that catches discrepancies. This logic represents 4,000 to 8,000 EUR.
What is the timeline for a real-time sync? Between 6 and 12 weeks: designing the event architecture, development, then load and resilience testing with your real volumes.
Let's scope your project. Describe the data to sync (stock, orders, prices), the number of channels and the cost of stale data: we quote batch or real-time, from 10,000 to 30,000 EUR. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
