Software solution

Custom SaaS Platform: Launch Your Software Product Faster

Start from a proven multi-tenant foundation with sign-up, billing, roles, admin and APIs already built, and spend your budget on the features that make your product different.

• Explore features

What the custom SaaS platform is

Every software-as-a-service product needs the same foundations before it can do anything useful: tenant isolation, sign-up and login, user roles, subscription billing, an admin console, audit logs, email notifications, an API and a secure, scalable cloud setup. Building those from scratch typically consumes a large part of a first release — and none of it is what customers pay for.

Syntrix's custom SaaS platform is a production-tested foundation that already provides those building blocks. We use it as the starting point for your product, then design and build your domain-specific features on top. You own the resulting product and its roadmap.

Who it is for

• Founders and start-ups launching a new B2B software product.
• Established businesses turning internal tools into products — for example, a specialist workflow you want to sell to peers.
• Software companies modernising a legacy single-tenant product into a multi-tenant cloud service.
• Industry groups and franchises that want to offer a white-labelled platform to members.

What is included in the foundation

Multi-tenancy

Tenant isolation at the data layer, per-tenant configuration and branding, and a choice of shared or dedicated databases for larger customers.

Identity and access

Email and social sign-up, single sign-on for enterprise tenants, multi-factor authentication, roles and permissions, and user invitations.

Subscription billing

Plans, trials, seat and usage-based pricing, invoices and dunning through your chosen payment provider.

Admin and operations

A super-admin console for tenants, plans, feature flags, impersonation for support and system health.

Developer platform

A versioned REST API, webhooks and API keys so your customers can integrate with you.

How we build your product

1. Product discovery — define your first release, users and differentiating features.
2. Foundation setup — your branded instance of the platform in your own cloud account.
3. Feature sprints — domain features built in two-week iterations with regular demos.
4. Launch and scale — monitoring, onboarding flows and a roadmap for the next releases.

Several of our other solutions, including the school management system, are themselves built on this foundation. For a wider view of the process and budgeting, see our SaaS development service and our guide to custom software development cost.

Next step

Request a demo of the foundation — tenant sign-up, billing, admin console and API — and we will outline what your first release would involve.

• At a glance

  • Platforms

  • Integrations

  • Pricing

• Built for

  • Professional Services

    Client portals, CRM, project and time tracking, billing and AI-assisted document workflows for consultancies, agencies, law and accountancy firms.

  • Education

    Software for schools, colleges and training providers: admissions, attendance, fees, timetables, gradebooks and parent communication in one connected platform.

  • Finance

    Secure software for lenders, brokers, accountancy practices and fintech teams: client portals, workflow automation, reporting and integrations with financial systems.

Features

Custom SaaS Platform features

• Multi-tenant architecture

  Secure tenant isolation with shared or dedicated database options.

• Sign-up, SSO and MFA

  Self-service onboarding plus enterprise single sign-on.

• Subscription billing

  Plans, trials, seats, usage pricing and dunning.

• Feature flags

  Enable features per plan or tenant and roll out gradually.

• White-labelling

  Per-tenant branding, domains and email templates.

• Public API and webhooks

  Versioned REST API with keys and event webhooks.

• Observability built in

  Logging, metrics, tracing and alerting from day one.

• Audit logs

  Tenant-visible audit trail of important actions.

Modules

Modular by design — use what you need

Start with the core and switch on modules as you grow. Every module is configurable to your processes.

• Tenant management

  Provisioning, configuration, branding and lifecycle.

• Identity

  Users, roles, invitations, SSO and MFA.

• Billing

  Plans, subscriptions, invoices and payment provider integration.

• Super-admin console

  Tenant oversight, feature flags, support tools and health.

• Notifications

  Email, in-app and webhook notifications with templates.

• Developer API

  REST endpoints, API keys, rate limiting and documentation.

Benefits

The difference it makes

• Faster time to market

  Skip months of foundation work and focus on your product.

• Lower technical risk

  Security, tenancy and billing patterns are already proven.

• Built to scale

  Cloud-native architecture that grows with your customer base.

• You own the product

  Your code, your cloud account and your roadmap.

Who it's for

Designed for your team

• Founders and product leaders

  A faster, lower-risk path to a first release.

• Businesses productising tools

  Turn an internal system into a sellable service.

• Software vendors

  Modernise a legacy product into multi-tenant SaaS.

• Industry networks

  Offer a white-labelled platform to members or franchisees.

Integrations

Connects with your tools

• Payment providers

  Subscription billing and invoicing through your chosen provider.

• Identity providers

  SAML and OpenID Connect for enterprise SSO.

• Email delivery services

  Transactional email with templates and tracking.

• Analytics and product tools

  Product analytics and customer feedback tools.

• AI services

  OpenAI and Anthropic Claude APIs for AI features in your product.

Documentation

Technical information & deployment

Deployment options

Your product is deployed into your own Azure or AWS account using infrastructure-as-code, with separate development, staging and production environments. Containerised services run on managed container platforms or Kubernetes where scale requires it.

Architecture

• ASP.NET Core back end with a modular structure, so domain features stay separate from the foundation.
• PostgreSQL or SQL Server with tenant isolation enforced at the data-access layer.
• React or Next.js front end; optional Flutter or .NET MAUI mobile apps.
• Background jobs, caching and message queues for scalable workloads.

Security

• Automated tests for tenant isolation, OWASP-aligned secure coding practices and dependency scanning in CI.
• Encryption in transit and at rest, secrets in a managed vault, and least-privilege cloud roles.
• Audit logging and support-access controls that tenants can see.

Ownership and hand-over

You own the source code for your product. The foundation is licensed to you perpetually for that product, and full documentation, CI/CD pipelines and runbooks are handed over. We can continue as your development partner or support your in-house team.

Onboarding

Discovery, foundation setup in your cloud account and the first feature sprint typically start within the first few weeks of engagement.

• Technology stack

  • ASP.NET Core

    ASP.NET Core is our default framework for secure web applications and REST APIs: fast, cross-platform and well suited to complex business logic and integrations.

  • Next.js

    Next.js lets us build fast, search-friendly React websites and web apps with server rendering, ideal for marketing sites, storefronts and SaaS products that need SEO.

  • PostgreSQL

    PostgreSQL is our open-source database of choice for SaaS platforms and cost-sensitive systems, with strong reliability, JSON support and vector search for AI features.

  • Docker & Kubernetes

    Containers with Docker and orchestration with Kubernetes for consistent environments, repeatable deployments and scalable hosting across Azure, AWS or private infrastructure.

  • Amazon Web Services

    We build and operate applications on Amazon Web Services, using managed containers, databases, serverless functions and storage with sound security and cost practices.

Case studies

Custom SaaS Platform in action

• AI Support Assistant for a B2B SaaS Company

  How a B2B SaaS company deployed a grounded AI support assistant that resolves 42% of conversations on its own and hands the rest to agents with full context.

• School Group Digital Transformation

  How a five-school trust replaced six disconnected tools with one school management platform and parent app, cutting admin time on attendance and fees by around 40%.

Portfolio

Related projects

• Smart Education ERP

  A unified education management platform for schools, colleges, universities, and multi-campus institutions, covering admissions, attendance, timetabling, fee management, examinations, academic records, and parent and student portals in one integrated system.

• AI Sales Assistant for B2B Teams

  An LLM-powered sales assistant that qualifies inbound leads, drafts tailored follow-ups and summarises accounts from CRM data for a B2B industrial supplier.

• Fleet Logistics Tracking App

  A driver app and dispatch dashboard for a regional delivery company, with live vehicle tracking, digital proof of delivery and optimised route sequencing.

What our clients say

• The assistant resolves the repetitive how-do-I questions and hands everything else to us with a proper summary. Our agents spend their time on the tricky tickets now, and customers get answers at 2am without us adding a night shift.

• We used to lose half a day's takings every time a store's broadband went down. Since the new tills went in, outages barely register, and head office can change a price at lunchtime and see it on every shelf-edge promotion by the afternoon.

• Parents now have one app instead of four, and our office teams have stopped spending Monday mornings chasing absence calls. The migration was the part we worried about most, and the trial runs meant there were no surprises on go-live day.

Services

Services to tailor and extend it

• SaaS Development

  SaaS development for start-ups and established companies: multi-tenant architecture, subscription billing, onboarding and admin tooling, built to scale securely on Azure or AWS.

• Cloud Application Development

  Cloud application development and migration on Azure and AWS: cloud-native architecture, containers, serverless, infrastructure as code and cost optimisation for reliable, scalable software.

• Web Application Development

  Custom web application development for portals, dashboards and line-of-business systems, built with ASP.NET Core, React and Angular and designed to scale with your business.

FAQ

Frequently asked questions

• Who owns the product we build on your platform?

  You do. You own the source code for your product and it runs in your own cloud account. The underlying foundation is licensed to you perpetually for that product, and all documentation and pipelines are handed over.

• How much faster is it than building from scratch?

  It removes the need to build tenancy, identity, billing, admin and API infrastructure, which often takes a large share of a first release. The exact saving depends on your product, but it lets most of the budget go on features your customers pay for.

• Can we add AI features to our SaaS product?

  Yes. The platform includes patterns for calling OpenAI and Anthropic Claude APIs securely, with per-tenant usage tracking so AI costs can be reflected in your pricing. Our AI web application development guide explains the options.

• Can you convert our existing single-tenant product?

  Often, yes. We assess your current codebase and either migrate it onto the foundation module by module or rebuild key parts. The approach depends on code quality, data model and how many customers are already live.

Guides

Helpful reading

• How Much Does Custom Software Development Cost?

  What drives custom software development cost: scope, integrations, team, compliance and support, with indicative ranges by project type and tips for controlling your budget.

• AI Web Application Development: A Practical Guide

  A practical guide to AI web application development: use cases, architecture, retrieval-augmented generation, choosing LLMs, security, evaluation, costs and delivery steps.

• ERP vs CRM: What's the Difference and Which Do You Need?

  ERP vs CRM explained: what each system does, how they differ, where they overlap, when you need one or both, and how to integrate them without duplicating data.

See the foundation in action

Request a demo of sign-up, billing, admin and API, and we will outline your first release.

Request a demo of sign-up, billing, admin and API, and we will outline your first release.

Contact

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