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Architectural Risk Comparison

Escape the Legacy Complexity of SAP Monoliths

A secure, serverless Next.js and Postgres database deployment designed to bypass the licensing tax of SAP S/4HANA — with 100% code ownership at handover.

Lock-in profile: Extreme (ABAP ecosystem, complex upgrade lockouts)

Quick Answer

In short: ERPStack provides a custom, license-free alternative to SAP S/4HANA. You get 100% data and IP ownership, zero seat-based fees, and a dedicated cloud deployment delivered in weeks.

Migration Blueprint Specification

Typical Annual Cost
$100,000 - $1,000,000+ / year (2026 list pricing)
Modularity
Very Low (Complex database dependencies, legacy tables)
Customization Limits
Highly rigid (Requires multi-month custom consulting cycles)
Extraction Pathway
Headless API encapsulation and progressive microservices extraction

The Escape Plan

Phase 14 Weeks

Strangler Fig Pattern Setup

Deploy API gateway to proxy requests between legacy SAP and new microservices.

Phase 23-6 Months

Module Extraction

Extract domains (e.g., HR, Inventory) one by one — phase 2 of the four-phase implementation timeline.

Phase 3Continuous

Data Lake Sync

Real-time replication from SAP HANA to PostgreSQL via Debezium.

Phase 4Final Month

Decommissioning

Turning off the legacy SAP modules permanently after 30 days of clean parallel-run validation.

Head-to-Head Architecture Matchup

7 of 7 capabilities shown

Capability comparison between a custom ERPStack build and SAP S/4HANA
CapabilityCustom ERPStack buildSAP S/4HANA
Deployment SpeedOperationsDays/Weeks (Vercel Edge)Months/Years (On-prem or SAP Cloud)
Developer EcosystemExtensibilityTypeScript / React / Node.jsABAP / Proprietary SAP tools
Real-time AnalyticsData & OwnershipEmbedded with ClickHouse/MaterializeRequires separate SAP BW/4HANA instance
Open Source StandardPlatform✓ Included✗ Not available
Manufacturing & Plant Maintenance (MRP/CMMS)OperationsMRP runs and CMMS maintenance scheduling engineered to your shop-floor requirements, with job costing for construction and project-based operationsPP and PM modules each licensed and configured separately
Business User ExperienceOperationsRole-specific React dashboards sized for the mid-size firm; user management and free read-only seats includedSAP GUI/Fiori access licensed per named user
Software Selection & ReviewsPlatformOne 2-week expert requirements audit replaces months of comparing vendors — the benefits and trade-offs land in a management-ready decision documentRFP cycles across analyst reviews, demo scripts, and integrator options

Legacy Pain Points

  • Multi-million dollar maintenance contracts
  • Complex legacy DB tables with ABAP lock-in
  • Extremely slow feature delivery times

The Custom Code Advantage

  • Modern headless APIs replacing legacy backend complexity
  • Dynamic static generation (Next.js) for high-speed reporting
  • Agile feature delivery weeks instead of months

Uncovering Hidden Constraints

What we don't do

Hidden Cost: Consulting Fees — stacked on the $100,000 - $1,000,000+ / year (2026 list pricing) base license

What we do

SAP requires certified integrators. Minor UI changes can cost $50k+ in consulting hours.

What we don't do

Hidden Cost: HANA Memory Costs — stacked on the $100,000 - $1,000,000+ / year (2026 list pricing) base license

What we do

In-memory databases are incredibly expensive for cold/archival data. A custom build keeps hot data in PostgreSQL and archives cold records to object storage at a fraction of the per-GB cost — typically over 10x cheaper.

What we don't do

Hidden Cost: Service & Support Tiers — stacked on the $100,000 - $1,000,000+ / year (2026 list pricing) base license

What we do

SAP Enterprise Support lists at 22% of license value annually, whether or not you open a ticket. A custom system carries a flat service retainer the business can scale down or cancel after the switch.

What we don't do

Hidden Cost: Software Evaluation Cycles — stacked on the $100,000 - $1,000,000+ / year (2026 list pricing) base license

What we do

Choosing between S/4HANA editions consumes months of vendor research, user reviews, and integrator options before any build starts. Hire one team instead: a fixed 2-week requirements audit produces a management-ready decision document.

Interactive TCO Model

Calculate Your 3-Year IP Savings

Drag the team-size slider to model SaaS licensing spend against a fixed-cost custom build — implementation, hosting, and 3-year TCO update in real time.

50 Users
10 seats500 seats
Proprietary SaaS (3-Year)
$325,000
  • • Base Implementation: $55,000
  • • License Taxation: $270,000
  • • Data Ownership: Rented
Custom Built ERP (3-Year)
$90,550
  • • One-Time Build: $55,000
  • Custom Hosting (3 Yrs): $10,800
  • Maintenance & Support (3 Yrs): $24,750
  • 100% Code & Data Ownership
Your 3-Year Savings
$234,450
Your 3-year overspend if you stay on SaaS
$234,450

Staying on per-seat licensing costs you $6,513 every month at 50 seats — spend that never converts into owned IP.

Discuss Your Custom Build

Why Companies Left SAP S/4HANA

"Reduced deployment times from 6 months to 1 week by migrating HR modules away from SAP to a custom Next.js stack."
A third-party logistics operatorReason: Inflexible UI and massive upgrade consulting costs.

Frequently Asked Questions

Yes. We use an API encapsulation model to intercept legacy requests, allowing you to migrate modules progressively without disrupting active systems — most teams extract their first module within 4 weeks.

Yes, our architectures leverage serverless edge routing and decoupled databases engineered for 99.9%+ availability targets with multi-region failover.

The migration runs four phases: a 4-week strangler-fig gateway setup, module extraction over 3-6 months, continuous data-lake sync via Debezium, and a final decommissioning month. Each extracted module passes a validation checklist — reconciled row counts, parallel-run comparisons, and user-acceptance sign-off — before the legacy SAP module switches off. Progressive extraction keeps active operations running throughout.

A mid-size firm facing a six-figure S/4HANA renewal is the usual candidate: hire one engineering team, run a 2-week requirements audit, and get a fixed quote — the benefits include zero named-user licensing, React dashboards your staff actually adopts, and module-by-module migration with no big-bang risk. Enterprises deeply invested in ABAP customizations may still be better served renewing.

Stop Renting SAP S/4HANA. Build Your Own.

Discuss a progressive migration pathway in a 30-minute architecture call — 100% of the code and IP transfers to you.

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