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NextGen Code

Software Engineering

SaaS development company for AI-native products, from MVP to scale

NextGen Code is a SaaS development company for founders and established businesses turning a proven problem into a subscription product. Our SaaS development services run from discovery and validation through UX design, MVP development (the smallest version customers will pay for), and launch, and we stay on to scale what works. Along the way we build the parts that are expensive to retrofit: multi-tenant architecture (one application serving many customer accounts, each walled off from the others), sign-in and roles, billing, and analytics.

This is for you if…

  • You've validated a problem through customer conversations or pilot users and need a product team to build the MVP.
  • You know an industry inside out and have a vertical SaaS idea, but no technical cofounder.
  • You built an internal tool that other companies keep asking to buy.
  • Your MVP was built fast and is cracking under real customers: no tenant isolation, manual billing, and no admin tools.
  • An enterprise prospect wants single sign-on, audit logs, and a security review before it signs.
  • You want AI in your product as a real differentiator, with unit economics that still work at scale.

Overview

From validated idea to paying customers: multi-tenant SaaS with billing, analytics, and AI built in.

AI changes the SaaS playbook in two ways. Built into the customer's workflow and fed with data only you have, it gives a young product a real differentiator. It also adds a cost traditional SaaS never had, because every AI request has a price, so we design pricing, usage limits, and model choices from day one to keep your margins healthy as usage grows.

We've built software products since 2018, including TownWave, a social music discovery platform that runs on web, iOS, and Android from one codebase, and the Sure Pick Sports recommendation platform prototype, designed and built for scale.

What you get

Deliverables, not decks.

  • 01

    Validated product scope

    Customer interview findings, a competitor teardown, positioning, pricing hypotheses, and a clickable prototype tested with target users. The output is an MVP cut list: the one job the product must do well on day one, and everything that waits.

  • 02

    UX and product design

    User flows, onboarding built around the moment the product proves its value, and a component-based design system in Figma that keeps the product consistent as it grows.

  • 03

    Multi-tenant application

    Organizations, invitations, and role-based permissions, with tenant isolation enforced in the database. When enterprise buyers need them, we add SAML single sign-on, SCIM provisioning (users added and removed automatically from the customer's identity system), and a customer-facing audit log.

  • 04

    Subscription billing

    Stripe Billing for plans, free trials, per-seat or usage-based pricing, proration, failed-payment recovery, sales tax, and a self-serve customer portal. Stripe webhooks drive entitlements, so a customer's access always matches what they pay for.

  • 05

    Analytics and admin console

    Product analytics and feature flags in PostHog or a similar tool, tracking activation, retention, and conversion. An internal admin console handles tenant management, support, and refunds, and lets your team view the app as a specific customer, with every session logged.

  • 06

    AI features with cost controls

    AI built into the core workflow, with an evaluation set, per-tenant usage metering, plan limits or credits, caching, and routing of simple tasks to smaller models, so every AI feature has a known cost per active user.

How it works

A clear process, start to finish.

  1. 012–4 weeks

    Discover and validate

    Customer interviews, a competitor teardown, pricing hypotheses, and a clickable prototype in front of target users. Where possible, we validate with pre-orders, letters of intent, or a paid pilot before the build starts.

  2. 022–3 weeks

    Design and architect

    UX flows and visual design, plus the decisions that are expensive to change later: tenancy model, authentication and roles, billing model, data model, and the analytics events that define activation.

  3. 038–12 weeks

    Build the MVP

    Sprints every 2 weeks, each ending in a demo, with a private beta environment, Stripe in test mode, and the admin tools your team needs to support the first customers.

  4. 042–4 weeks

    Beta and launch

    A beta cohort or a few design partners (early customers who help shape the product) use it while we watch where they get stuck and remove the friction. Then you launch with onboarding emails, a help center, a status page, and support workflows in place.

  5. 05Ongoing

    Iterate and scale

    Weekly metric reviews and customer conversations set the roadmap. As usage grows, we add background job queues, caching, database read replicas, load testing, and monitoring of cost per tenant.

What we measure

The numbers this moves.

We baseline these before we start and report against them after launch.

  • Time to first paying customer

    The date the whole plan works backward from. Scope cuts during discovery protect it.

  • Activation rate

    The share of new signups who reach the moment the product proves its value, defined during discovery and tracked from the first beta user.

  • Retention by cohort

    How many customers and users are still active each month after signing up, the clearest early signal that the product is worth paying for.

  • AI cost per active user

    Model and infrastructure cost per active user, compared with plan price. The target is a margin that holds up when your heaviest users arrive.

  • Release cadence

    How often improvements reach customers. The target is weekly releases, backed by automated tests so speed doesn't break what already works.

In practice

What this looks like in a real business.

  • Vertical SaaS from industry expertise

    Example: a former property manager turns her spreadsheet process into a subscription product for small landlords, with multi-tenant accounts, Stripe billing, and AI that drafts lease summaries and replies to maintenance requests.

  • An internal tool turned into a product

    Example: a regional trucking company built a dispatch tool for itself, and other carriers want to buy it. Adding tenant isolation, onboarding, billing, and an admin console turns it into a product and a potential second revenue line.

  • A consumer social platform

    TownWave is a social music discovery platform. We handled the design, wireframes, and build, and shipped it from one codebase across web, iOS, and Android.

  • A prototype built to scale

    Sure Pick Sports needed a prototype of its sports-betting recommendation platform. We designed and built it for scale, so the architecture can grow with the product instead of being thrown away after the demo.

  • An AI-native workflow product

    Example: a product that reads incoming requests for proposals and drafts responses from a company's past proposals, with citations and a review step. The moat is the customer's own content and the workflow around it, not the model, which can be swapped as better ones arrive.

  • A usage-based API product

    Example: a data service sold by the API call, with API keys, rate limits by plan, Stripe usage-based billing, a developer dashboard, and documentation clear enough that customers can integrate without a sales call.

Tools & platforms we work with

  • Next.js
  • React
  • TypeScript
  • Node.js
  • PostgreSQL
  • Stripe
  • Clerk
  • WorkOS
  • PostHog
  • Sentry
  • Vercel
  • AWS
  • Figma

We're vendor-neutral: we recommend what fits your stack, budget and risk profile — not what pays us a referral fee.

Next step

Let's talk about SaaS Development.

Bring a problem or a goal. In 30 minutes we'll tell you what's realistic, what it would take, and where AI fits — even if the answer is to start smaller.

FAQ

SaaS Development: common questions

Still have a question? Ask us directly.

How much does it cost to build a SaaS MVP?

The cost of a SaaS MVP comes down to scope, and the drivers are easy to name: the number of core workflows at launch, user roles and permissions, integrations, billing complexity (flat plans are simpler than seats plus usage), AI features that need evaluation work, and enterprise requirements such as single sign-on and audit logs. The most affordable MVP does one job well. We cut scope with you during discovery, then give you a fixed price for the MVP so you can plan your runway.

How long does it take to build a SaaS product?

A focused SaaS MVP typically takes 3–6 months from kickoff to public launch: 2–4 weeks of discovery and validation, 2–3 weeks of design and architecture, 8–12 weeks of building, and a 2–4 week beta. Validation is where timelines are won, because it's where features get cut. Launching a narrow product in 4 months and learning from paying users beats spending a year on features nobody asked for.

Should our SaaS be multi-tenant or single-tenant?

Multi-tenant, for most B2B products. In a multi-tenant (pooled) design, every customer shares one application and database, and each row carries a tenant ID enforced by PostgreSQL row-level security, a database rule that stops one customer from reading another's data. It's cheaper to run and simpler to update. Single-tenant (siloed) setups, with a dedicated database per customer, suit regulated or very large customers who require isolation. We design the data layer so a big customer can move to a dedicated database later without a rewrite.

How do you price AI features without losing margin?

Price AI features from the cost per active user, and measure it from day one. Example: if a typical user triggers 300 AI requests a month at about $0.01 each in model fees, that's $3 per user per month, easy to absorb on a $49 plan. A power user running 10 times that costs $30 and erases the margin. So we meter AI usage per tenant, set plan limits or credits, cache repeated context, and route simple tasks to smaller, cheaper models. A model price change then shows up on a dashboard, not in your gross margin.

Who owns the code, and will it hold up to investor due diligence?

You own the code and the intellectual property, and we set it up the way investors and acquirers expect to find it: IP assignment from everyone who touches the code, the repository and cloud accounts in your company's name, an inventory of open-source licenses, and documentation of the architecture and deployment. Technical due diligence goes looking for exactly these gaps, and closing them during the build costs far less than closing them in the middle of a fundraise.

Do I need a technical cofounder to build a SaaS product?

Not to launch, but you do need technical leadership. Founders regularly reach their first paying customers with an outside product team, as long as someone experienced owns the architecture, the roadmap, and the trade-offs. We can fill that role, as your product team or as a fractional CTO, and help you hire your first engineers once traction justifies it. Some investors want an in-house technical leader before a later round, so we document everything with that handoff in mind.

Do you charge fixed-bid or time and materials, and what happens after launch?

We fixed-bid the MVP once discovery has settled the scope, because founders need to plan runway. After launch the work changes: you learn from users every week, so a monthly product retainer or time-and-materials sprints fit better than a fixed scope. That ongoing work covers new features, performance and scaling, security updates, monitoring, and the analytics reviews that decide what to build next. If you hire your own team, we transition the codebase with documentation and pairing sessions.