# SaaS & Custom Software Guides: Architecture, ERP, Migration | Alher Tech

> Senior-level guides on choosing custom vs SaaS, building custom ERPs, multi-tenant architecture, and migrating legacy systems. The Alher Tech playbook for shipping enterprise software in 2026.

- Canonical page: https://alhertech.com/en/saas-guides/
- Site: Alher Tech (custom software, AI agents and SEO engineering, https://alhertech.com/)
- Contact: https://alhertech.com/en/contact/

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Senior-level guides on custom vs SaaS, ERPs, multi-tenant architecture and legacy migration, written for CTOs and engineering leads.

- [Custom Software vs SaaS: How to Choose for Your Business in 2026](https://alhertech.com/en/saas-guides/custom-software-vs-saas/)
Buying SaaS is faster. Building custom is cheaper at scale and gives you the moat. The decision framework we use with clients: TCO over 5 years, integration cost, switching cost, and the build-vs-buy decision matrix.

- [Custom ERP Development: When to Build, How Much It Costs and What to Avoid](https://alhertech.com/en/saas-guides/custom-erp-development/)
Most custom ERP projects fail. The ones that succeed start narrow, replace SAP/Oracle module by module, and use modern stack. The 2026 playbook for building ERPs that actually ship and deliver value in 6-12 months.

- [Multi-Tenant SaaS Architecture: Database Strategies, Scale and the Real Trade-Offs](https://alhertech.com/en/saas-guides/multi-tenant-saas-architecture/)
Choosing your multi-tenancy strategy on day one shapes the next 5 years. Shared DB, schema-per-tenant, DB-per-tenant: when each wins, performance numbers, isolation guarantees, and how to migrate later if you guessed wrong.

- [Legacy System Migration: Strangler Pattern, Risk Management and the 18-Month Plan](https://alhertech.com/en/saas-guides/legacy-system-migration/)
Big-bang rewrites kill companies. Strangler-pattern migrations win. The detailed 18-month playbook for replacing legacy COBOL/Java/Oracle systems without downtime, with reversible steps and continuous business value delivery.

- [Building a SaaS MVP in 8-12 Weeks: The 2026 Stack and Process](https://alhertech.com/en/saas-guides/saas-mvp-development/)
SaaS MVPs in 2026 ship in 8-12 weeks if scoped right and 6-9 months if not. The stack that wins (Next.js + Supabase or Spring Boot + Postgres + Stripe), the process that ships, and the product mistakes that turn a 10-week MVP into a 12-month build.

- [SaaS Pricing & Billing: Stripe Implementation, Plans, Metering and Annual Discounts](https://alhertech.com/en/saas-guides/saas-pricing-billing-implementation/)
SaaS billing is where pricing strategy meets engineering reality. Per-seat, usage-based, hybrid, freemium, annual discount, dunning, proration. The 2026 reference implementation on Stripe Billing, including the metering pipeline, webhook handlers and the pricing changes you can ship without migrating customers.

- [API-First SaaS Architecture: Why It Matters in 2026 and How to Build It](https://alhertech.com/en/saas-guides/api-first-saas-architecture/)
API-first architecture isn't a slogan. It's an operational discipline. SaaS that ships API-first wins integration deals, ships customer-specific features without forking, and makes AI agents possible. The architecture, the contract discipline and the OpenAPI/SDK pipeline.