SaaS Platforms ThatScale to Millions
Enterprise-grade multi-tenant architecture with subscription billing, advanced analytics, and scale-ready infrastructure. Built for startups through unicorns. SOC2 certified.
Enterprise SaaS Built-In
All the infrastructure you need to launch, grow, and scale your SaaS platform
Multi-Tenancy Architecture
Complete data isolation with shared infrastructure. Row-level security, tenant switching, isolated databases or namespace strategies.
Billing & Subscriptions
Stripe, Paddle, usage-based pricing, seat-based models, dunning management, automated invoicing, and revenue recognition.
Enterprise Auth & SSO
OAuth 2.0, SAML, OIDC, MFA, passwordless auth, role-based and attribute-based access control for any org size.
Analytics & Metrics
Real-time dashboards, cohort analysis, funnel tracking, event streaming, and revenue intelligence for your team.
Notification Engine
Email, SMS, push, in-app, webhooks. Templating, scheduling, delivery tracking, A/B testing, and orchestration.
API-First Platform
RESTful and GraphQL APIs, webhooks, SDK generation, rate limiting, API versioning, and developer portal.
5-Phase SaaS Build
Product Architecture
Define your SaaS product architecture, pricing model, tenant strategy, and core feature set before writing a line of code.
1–2 weeksFoundation Build
Auth, multi-tenancy, billing, and user management first. The platform foundation that everything else builds upon.
3–4 weeksFeature Development
Core product features in 2-week agile sprints. Customer feedback loops integrated early to validate product-market fit.
Ongoing sprintsSecurity & Compliance
SOC2 controls implementation, penetration testing, vulnerability scanning, and compliance documentation.
Parallel to devLaunch & Scale
Production deployment, customer onboarding flows, monitoring setup, and infrastructure auto-scaling for growth.
1–2 weeksModern SaaS Stack
SaaS Models We Build
B2B SaaS Platforms
Multi-tenant B2B tools with enterprise SSO, RBAC, advanced reporting, and white-label customization for enterprise buyers.
Enterprise, SMB
Developer Tools & APIs
API-first platforms with developer portals, sandbox environments, usage-based billing, and SDK generation.
DevTools, FinTech API
Vertical SaaS
Industry-specific SaaS for healthcare, legal, construction, or logistics with domain-specific workflows and compliance.
Healthcare, Legal, Construction
Usage-Based Platforms
Metered billing platforms that charge based on API calls, storage, seats, or custom usage metrics with real-time tracking.
API, Cloud, Infrastructure
White-Label SaaS
Re-brandable SaaS platforms sold to channel partners or agencies with isolated tenant customization and custom domains.
Agencies, Channel Sales
Marketplace Platforms
Two-sided marketplace platforms with seller onboarding, commission splits, escrow, reviews, and dispute management.
Marketplace, Gig Economy
Featured Success Story
Series B Enterprise SaaS Company
Multi-Tenant CRM Platform Rebuild
Challenge
Off-the-shelf portal with poor UX causing 35% customer churn. No enterprise SSO, no white-label, no usage analytics. Support team overwhelmed with 200+ tickets/day.
Solution
Rebuilt as a fully multi-tenant SaaS with WorkOS SAML SSO, Stripe subscription billing, real-time usage dashboards, custom theming per tenant, and a native iOS/Android app.
Fixl vs. Typical SaaS Vendors
What Our Clients Say
“Fixl built our entire multi-tenant SaaS platform in 16 weeks. Enterprise SSO, usage-based billing, and a white-label system that our channel partners love. Simply the best.”
“We scaled from $500K to $5M ARR in 18 months after Fixl rebuilt our platform. The API-first architecture they designed opened three new revenue channels we hadn't anticipated.”
“The usage-based billing system they built handles $2M in monthly transactions flawlessly. Zero billing errors in 14 months, and the metering is accurate to the millisecond.”
How We Engage
SaaS MVP Launchpad
Full SaaS foundation in 8–12 weeks: auth, multi-tenancy, billing, and core product.
Dedicated SaaS Team
Full-time product engineers embedded in your startup or scaleup.
Growth Engineering Retainer
Ongoing feature development, A/B testing, and platform scaling support.
SaaS Platform Questions
Ready to Build Your SaaS?
From MVP to enterprise scale — we've helped 50+ SaaS companies reach millions in ARR. Let's build yours next.