I will build your b2b saas platform with nextjs, postgresql, and go

C
csalguero441
C
csalguero441
Carlos Salguero
build your b2b saas platform with nextjs, postgresql, and go
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build your b2b saas platform with nextjs, postgresql, and go
Full Screen
build your b2b saas platform with nextjs, postgresql, and gobuild your b2b saas platform with nextjs, postgresql, and go

About this gig

Most SaaS products don't fail because of the idea. They fail because the first version was built for speed, not scale -- months layer you're paying to rewrite everything.


I build the version that survives real users.


As a full-stack architect with Fortune 500 experience, I bring technical depth and product judgement to every engagement. You get someone thinking about long-term architecture, not just the next ticket.


Why Choose Me

  • Architecture First: data model, auth, and tenant isolation locked before code is written
  • 95% Test Coverage: every module ships with a full test suite -- no black boxes
  • You own everything: code, infra, docs -- zero lock-in


What You Get

  • Next.js + TypeScript
  • Next.js, NestJS, or Go backend
  • PostgreSQL with row-level security
  • JWT, OAuth2, or SSO auth
  • Multi-tenant architecture
  • Stripe billing and subscriptions
  • Swagger/OpenAPI docs
  • Vercel, Railway, or AWS deployment


What I Build

  • B2B SaaS MVPs and applications.
  • Multi-tenant PropTech, FinTech, HealthTech systems
  • CRMs, dashboards, and subscription billing
  • AI-augmented backends with RAG and semantic search


Not a Fit: WordPress, Shopify themes, mobile-only apps, or undefined scope.

  • Website type

    • Saas

  • Programming language

    • JavaScript
    • TypeScript
    • React
    • Tailwind CSS
    • Angular

  • Website features

    • Payment
    • Inventory
    • Analytics
    • Booking
    • Calendar
    • Dashboard
    • Reviews
    • Landing page
    • User Authentication
    • Admin Panel

Gig milestonesNEW

Choose to pay for your project per milestone by only paying when it’s time to start a new one or decide on a 1-time payment.

    Basic Package.
    These are the steps we’ll follow to complete your project.
  • 1st Milestone: Planning
    1-day delivery · 1 revision
    $50Pay now

    I'll use your provided requirements to start planning your website.

  • 2nd Milestone: Website Design
    1-day delivery · No revisions
    $75
    Pay later

    I'll create the design for your website.

  • 3rd Milestone: Development
    3-day delivery · 1 revision
    $175
    Pay later

    I'll develop the website and deliver a working product for your review.

  • 4th Milestone: Progress check
    1-day delivery · 1 revision
    $50
    Pay later

    We'll meet to review your project status and the steps needed to finish it.

  • 5th Milestone: Delivery
    1-day delivery · No revisions
    $50
    Pay later

    I'll send you the final delivery for review and feedback.

Respect third-party rights

Please be aware that it is against Fiverr's policies for sellers to include themes, templates, or any other elements that infringe third-party rights or applicable laws in the delivered work. Read more about in our Guide to Responsible Digital Creation.

Get to know Carlos Salguero

Carlos Salguero

Senior AI Systems Architect and Backend Engineer

5.0(2)
  • FromMexico
  • Member sinceNov 2024
  • Avg. response time7 hours
  • Last delivery4 weeks

  • Languages

    English, Spanish, German, Korean
Senior AI Systems Architect & Backend Engineer. I specialize in high-performance infrastructure and production-grade RAG pipelines. With experience processing 100k+ daily records at Fortune 500 scale (PPG Industries), I build secure, deterministic systems. IEEE-published researcher (CHILECON 2025) and founder of Qantara Systems. I engineer using Go, Rust, and Python, ensuring a strict 95% test coverage standard. CS graduate from Tec de Monterrey. I don't build wrappers; I build production ecosystems. Message me for complex requirements.

My Portfolio

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