SaaS Product Development
Sign-up, login and permissions done properly
Login is the front door of your product. We build authentication and permissions that are secure, easy for users and ready for business customers.
The problem
The problem this solves
Authentication looks simple until you list what it must handle: sign-up, email verification, password resets, social login, two-factor codes, sessions on several devices, locked accounts, invitations, and business customers who want to log in with their company account. Each one is a place where a small mistake becomes a security hole.
Permissions are the second half of the problem. As a product grows, "admin or not" turns into owners, managers, editors, viewers and guests, each allowed to do slightly different things. Rules end up scattered through the code, and nobody can say for sure who is able to do what.
We use proven building blocks for the security-critical parts, such as established auth libraries or providers, rather than writing cryptography by hand. Then we design a permission model that is written down in one place, enforced on the server and tested automatically. For products sold to companies, we add single sign-on and user provisioning, which are often required to close larger deals.
We keep the user side friendly as well. Clear error messages, sensible password rules, passwordless options and fast recovery reduce support tickets and help more new users reach the product instead of stalling at the login screen.
What you get
What you get
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Sign-up and login
Email and password, magic links and social login, with email verification and rate limits.
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Two-factor authentication
Authenticator apps, passkeys or email codes, required for admins and optional for users.
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Single sign-on
SAML and OpenID Connect login for business customers using Google Workspace, Microsoft Entra ID or Okta.
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Organizations and invitations
Teams, invitations, ownership transfer and user removal that fit a multi-tenant product.
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Roles and permissions
A clear permission model enforced on the server, with custom roles when customers need them.
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Session management
Device lists, remote sign-out and session limits for sensitive accounts.
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Security logging
Logins, failed attempts and permission changes recorded for audits.
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Admin tools
Support staff can help users safely, for example by resetting access, with every action logged.
How we build it
How we build it
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1
Requirements
We list user types, login methods, customer security demands and compliance needs.
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2
Permission model
Roles and rules written down in one table everyone can read.
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3
Choose the auth approach
Library or hosted provider, compared on cost, control and lock-in.
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4
Build
Flows, permission checks and admin tools built with tests for each role.
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5
Security review
We test for common attacks and check every endpoint enforces permissions.
AI and people
Where AI helps, where people decide
AI makes the repetitive parts faster. The decisions that shape your product stay with experienced people.
Where AI speeds things up
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Generating permission tests for every endpoint and role.
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Reviewing code for endpoints that forget to check permissions.
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Drafting login, reset and invitation emails.
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Building the admin screens for users and roles.
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Documenting the permission model for your team and customers.
Where people decide
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Which auth provider or library to trust.
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The permission model and its edge cases.
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Password, session and two-factor policies.
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How support staff may access customer accounts.
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Whether the system passes security review.
Is this right for you?
When this is the right choice
A good fit when
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You are building a product where users log in.
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Business customers ask for single sign-on or audit logs.
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Permissions have grown messy and hard to reason about.
Consider something else when
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Your site has no logged-in area at all.
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An existing product already covers your team's internal login needs.
Timeline and cost
What affects the timeline and cost
Standard login, roles and two-factor authentication usually take one to a few weeks within a larger build. Single sign-on, custom roles per customer and migration of existing users add time.
We do not publish fixed prices because scope drives cost. How we estimate.
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Login methods
Each method, such as social login, magic links or passkeys, adds flows to build and test.
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Enterprise single sign-on
SAML and provisioning add setup and testing with each identity provider.
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Permission complexity
Custom roles and record-level rules take longer than a few fixed roles.
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Provider choice
Hosted auth providers save build time but add monthly fees.
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User migration
Moving existing users without forcing password resets needs careful work.
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Compliance
Health, finance or government customers may require extra controls and logs.
Keep exploring
Related services, solutions and reading
Related services
View all related services- SaaS Product Development MVPs, subscription platforms, admin panels and multi-tenant products, planned to grow past the first launch.
- API development Well-documented APIs that let your product talk to apps, partners and AI tools reliably.
- Multi-tenant architecture One product serving many customer accounts, with each account's data kept separate and secure.
- Mobile App Development iOS, Android and cross-platform apps with the backend and APIs they need, taken all the way to the app stores.
- AI Product Development AI agents, knowledge assistants, copilots and document automation built into the way your team already works.
- MVP development A first version with just enough features to put in front of real users and learn what to build next.
Solutions
View all solutions- Onboarding automation Every new hire gets the right accounts, documents, training and check-ins on time, tracked in one place.
- Compliance tracking Track filing deadlines, licenses and obligations in one place, with reminders and AI summaries of relevant rule changes.
- Internal help desk assistant An assistant in Slack or Teams that answers policy and how-to questions from your handbooks and opens tickets when needed.
- Feedback analysis Read every review, survey and ticket, group them by theme and sentiment, and show what customers keep asking for.
- Payroll automation Turn pay rules, attendance and leave into tested software so the monthly run becomes a review and payslips go out in one batch.
Industries
View all industries- SaaS and startups MVPs, subscription billing, AI features, multi-tenant platforms and scaling support for founders and product teams.
- Healthcare Patient booking, intake forms, internal knowledge assistants and admin automation for clinics and care providers.
- Finance and accounting Client portals, document collection, invoice and receipt processing, and reporting for accounting firms and finance teams.
Case studies
View all case studies- Facility management platform Every request, inspection and cost for every building now lives in one place, with a clear owner and status.
- Payroll system for an IT services company Payroll is calculated from recorded inputs, reviewed once and sent as payslips in a single batch, with every change logged.
- Tax filing service platform Clients upload documents and see where their case stands, and staff work from one queue with deadlines and reminders.
Guides and articles
View all guides and articles- AI development security checklist A practical checklist for keeping code, data and credentials safe when a team builds with AI tools.
- How to keep customer data safe when using AI Practical steps to protect customer data when you use AI services, from data terms to access and logging.
- MCP security best practices How to choose, configure and monitor MCP servers so AI assistants get the access they need and nothing more.
- How to build a customer portal Plan and build a portal where customers see status, share documents and help themselves, safely.
- Multi-tenant SaaS architecture explained How SaaS products serve many customers from one system, the main design options and how to choose.
MCP servers
View all mcp servers- Developer tools Servers for code hosting, version control, files, containers, error tracking and documentation lookup.
- AWS The AWS API MCP server from AWS Labs lets AI run AWS CLI commands, suggest commands and plan changes, with read-only and consent modes.
- Azure Microsoft's Azure MCP server lets AI work with many Azure services, from storage and Key Vault to SQL, monitoring and AKS, with a read-only mode.
- Cloudflare Cloudflare's Code Mode MCP server lets AI search Cloudflare docs and the API and execute API calls, within the scopes you grant.
- Coolify Coolify's official MCP server lets AI see self-hosted infrastructure, find unhealthy resources, review deployments and deploy with the right token.
- Google Cloud Google's gcloud MCP servers let AI run gcloud commands, read logs, metrics, alerts and traces, and work with Cloud Storage.
Glossary terms
View all glossary terms- User authentication User authentication is how an application confirms who a user is, through passwords, sign-in links, single sign-on or other methods, before giving access.
- Multi-tenant Multi-tenant describes software where one application and database serve many customers, called tenants, while keeping each customer's data separate.
- API An API, or application programming interface, is a defined way for one piece of software to request data or actions from another.
- Database A database is an organized store of data that software can search, update and keep consistent, such as customers, orders or bookings.
- SaaS SaaS, or software as a service, is software delivered over the internet on a subscription, rather than installed and owned by each customer.
FAQ
Questions about user management and authentication
Have a question that is not here? Ask us directly.
Use proven components either way. Hosted providers such as Auth0 or Clerk are quick and feature-rich but cost more as you grow. Open-source libraries give more control at lower running cost. We compare both for your case.
Single sign-on lets business customers log in with their company account, such as Google Workspace or Microsoft. Many larger customers require it, so it matters if you sell to companies.
Permissions are checked on the server for every request, defined in one place and covered by automated tests for each role. Hidden buttons in the interface are never the only protection.
Usually yes, often without forcing everyone to reset their password. We plan the migration carefully and test it on a copy first. See how we handle security.