B2B SaaS App Development · Fixed Price · 8 Weeks · PM & Senior Engineers Included

Jake McMahon
Led by Jake McMahon
$15K–$500K ticket-size deals closed using this system · Built an agency to $1.5M ARR in 12 months · LinkedIn

Fixed price. 8 weeks. Scope guarantee. The three things your dev shop can’t offer simultaneously.

Written spec signed before we write a line of code. A PM who owns sprint decisions. Senior engineers whose code your next hire can read.

8 weeks to first paying users. Fixed price.

Free 30-minute scoping call. Written estimate after. No commitment required.

App Build Sprint

Duration 8 weeks, contractual
Price model Fixed price, signed spec
Team PM + 2 senior engineers
Stack React · Laravel/Node.js · PostgreSQL
Guarantee Sprint 1 free if missed
8-week delivery — contractual, not aspirational· React · Laravel/Node.js · PostgreSQL· Written spec signed before development starts· Sprint 1 free if we miss scope

“I spent $50K on an agency and got a half-working MVP I can’t ship.”

Every offshore dev shop says fixed price. The contract says “time and materials” on page 3. Here is what the burned founder already knows.

“Eight months. $60K. A zip file with no documentation and code nobody else can read.”

The offshore shop delivered eventually. What they delivered was a codebase only they understand — vendor lock-in baked into the architecture. Your next developer quotes a $40K rewrite before touching anything.

“I managed the developers instead of running the business. Every spec gap cost me a week.”

No PM means the founder is the PM. Every “is this what you meant?” lands in your inbox at midnight. You hired engineers — nobody told you you were also buying a second job.

“The scope crept. The price crept. The deadline moved three times. Nothing was in writing.”

Vague contracts are designed for the vendor’s benefit. Scope creep is not an accident — it is a business model. A written spec signed by both parties before development starts is the only structural fix.

“I tried no-code. Hit the ceiling at $80K ARR when I needed real auth and multi-tenancy.”

Bubble is fast to start and expensive to rewrite. Every B2B SaaS hits the no-code ceiling. The question is whether you hit it at $0 ARR or at $300K ARR — when the forced rewrite costs the most.

A working B2B SaaS in 8 weeks. Not a roadmap. A live app.

The App Build Sprint delivers a deployed, instrumented, documented product — in your repository, on your infrastructure, owned entirely by you.

Written technical specification, signed before development starts

Exact scope, architecture, acceptance criteria. Signed by both parties. The mechanism that makes fixed price real — no written spec means no fixed price, regardless of what the proposal says.

Backend & API — Python/Node.js/Laravel + PostgreSQL + Redis

RESTful or GraphQL API, documented. Authentication (email/password + OAuth), multi-tenant architecture, RBAC, unit tests on critical paths. Industry-standard, investor-legible, infinitely extensible.

Frontend — React (TypeScript) with component library

Desktop-first for B2B SaaS, mobile-ready. Form handling, loading states, error boundaries. Implemented from your Figma designs or from standard component library if none provided.

Integrations scoped at intake — Stripe, SendGrid, PostHog, OAuth

Standard integrations included. CRM or ERP integrations (HubSpot, Salesforce) scoped per your stack and agreed in the written spec — not discovered as extras at week six.

Infrastructure & CI/CD — Docker, GitHub Actions, AWS/GCP

Staging and production environments. SSL, uptime monitoring, database backups, structured logging. Your product ships production-grade, not staging-ready.

Analytics instrumentation — PostHog event tracking from day one

Key user actions tracked, funnel configured, error monitoring live. You can see on launch day whether the product is working — not in a retrospective report six weeks later.

Full documentation handover — architecture, API, deployment runbook

Architecture diagram, database schema, API docs, deployment runbook, environment variable reference, onboarding notes for your next developer. Source code delivered to your repository, not ours.

Every sprint ends with a demo and a signed acceptance checklist.

The timeline is contractual. Each sprint has defined deliverables, defined acceptance criteria, and a signed checklist before the next sprint begins. No surprises at week six.

Weeks 1–2

Sprint 0: Foundation

Sprint goal

Working skeleton. Auth, database schema, CI/CD running, staging live.

  • Project repository setup — client owns from day one
  • Authentication system (email/password + OAuth)
  • Database schema v1, confirmed against spec
  • API skeleton with authenticated endpoints
  • Frontend scaffold with routing, layout, auth screens
  • Staging environment deployed, CI/CD pipeline running

Acceptance criteria

Client can log in, view authenticated dashboard, and be assigned a role. All engineers can deploy to staging via CI/CD. Database schema reviewed and approved.

Weeks 3–4

Sprint 1: Core Feature

Sprint goal

Primary user-facing feature working end-to-end. Not polished, but functional.

  • Primary application feature built per the signed spec
  • Core data models fully implemented
  • API endpoints for primary feature complete
  • Frontend implementation, desktop-first
  • Basic error handling and loading states

Scope guarantee applies here

If Sprint 1 does not deliver the agreed core feature as defined in the spec, the team extends Sprint 1 at no additional cost until acceptance criteria are met. This is in the contract.

Weeks 5–6

Sprint 2: Integrations

Sprint goal

Secondary features and integrations. Product is getting close to complete.

  • Secondary features as defined in spec (user management, notifications, settings)
  • Billing integration — Stripe or Paddle
  • CRM or ERP integration if in scope
  • Transactional email, secondary screens and flows

Acceptance criteria

Billing: test subscription creation, upgrade, and cancellation. Integrations: end-to-end data flow verified with client’s test accounts. Secondary features: demo walkthrough with client.

Weeks 7–8

Sprint 3: Production Launch

Sprint goal

Production-grade. Ready for real users.

  • Production environment deployed, SSL live
  • Analytics and event tracking instrumented and verified
  • Error monitoring live, performance baseline established
  • Security review — headers, rate limiting, input validation
  • Full documentation package delivered, source code to client repository
  • Database backup verified, environment credentials transferred

Final acceptance

Client logs in on production. Backup restore verified. Documentation reviewed. All credentials transferred. Final acceptance sign-off. 30-day warranty period begins.

The budget risk that kills offshore projects is structurally removed.

The scope guarantee is not a marketing claim. It is in the contract. Here is exactly what it covers and what it does not.

What is guaranteed

At the end of Sprint 1 (weeks 3–4), the deliverables agreed in the signed technical specification are either delivered to acceptance criteria and invoiced, or not fully delivered — in which case the team continues Sprint 1 work at no additional cost until acceptance criteria are met.

What triggers the guarantee

Sprint 1 deliverables were agreed in the signed spec and accepted by both parties. The team did not deliver them to the agreed acceptance criteria by the end of week 4.

What the guarantee means

The team continues Sprint 1 at no additional charge until the agreed acceptance criteria are met. Not a credit. Not a negotiation. Continuation until done.

What is not covered

Requirements not in the signed spec. Changes requested after signing. Delays caused by client-side dependencies — third-party credentials not provided, feedback not given within 48 hours.

How scope changes work

All scope changes are discussed between sprints, not within them. Each change is presented with description, estimated time, estimated cost. Client approves or declines before the next sprint begins.

Cancellation: if you cancel after Sprint 0 but before Sprint 1 begins, you owe nothing beyond the Sprint 0 fee. No lock-in to a full 8-week engagement until Sprint 1 acceptance.

PM and senior engineers. No account manager between you and the people building.

Every App Build Sprint includes

Standard configuration: 1 Project Manager + 2 Senior Engineers. This is the minimum configuration. Larger builds are staffed accordingly at the scoping session.

Project Manager (1 FTE equivalent)

  • Owns the written technical specification
  • Runs sprint planning and acceptance sessions
  • Single point of contact — makes decisions, doesn’t relay messages
  • Holds the scope boundary so the fixed price holds
  • Runs the free 30-minute scoping session before contract signing
  • Available: synchronous during business hours, async within 4 hours

Senior Engineers (2)

  • React (frontend), Laravel or Node.js (backend), PostgreSQL (database)
  • 5+ years production B2B SaaS experience each
  • Write tests for critical paths
  • Write architecture documentation as part of the deliverable
  • Participate in sprint demo with client
  • Code your next hire can read on day one

Not included in standard sprint

Dedicated QA engineer (testing handled by engineers) · Designer (we implement from your Figma, or standard component library if none provided) · Data engineer (analytics instrumentation included; data warehouse is an upgrade) · DevOps (deployment automation included; bespoke multi-region infra is an upgrade)
Jake McMahon
Jake McMahon — Founder, ProductQuant

I’m Jake. 8+ years in B2B SaaS product and growth — not as a developer shipping features, but as the person accountable for whether those features moved the business. I’ve scoped, staffed, and delivered product sprints across healthtech, adtech, edtech, and B2B tools.

I started ProductQuant because I kept seeing the same problem: founders managing dev shops with no product thinking in the team. Engineers shipped exactly what the brief said. The brief was wrong. Nobody caught it until the feature was live and the metrics didn’t move.

Background BSc Behavioural Psychology · MSc Data Science
Experience 8+ years B2B SaaS product & growth
Industries Healthtech · Adtech · Edtech · AI tools
Evgeniy Bogoyavlenskiy

Evgeniy Bogoyavlenskiy

Senior Fullstack Developer

10+ years building backend systems, APIs, and data pipelines. Specialises in PHP/Laravel, Node.js, React, and complex architecture. Backend that your next hire reads and maintains without calling the original agency.

PHP / Laravel Node.js React PostgreSQL RabbitMQ
Alexander Dudnik

Alexander Dudnik

AI & Full-Stack Engineer

7+ years shipping distributed systems and AI-integrated applications. Technical team lead with deep experience in Node.js, TypeScript, and C#/.NET. Has built real-time voice+vision assistants, GPT-powered publishing engines, and SSE streaming systems.

Node.js / TypeScript React 18 C# / .NET Azure / AWS
Varazdat Tsarukyan

Varazdat Tsarukyan

Full-Stack Engineer

7+ years building full-stack web applications with a focus on React, TypeScript, and NestJS. Deep experience designing and shipping multi-module platforms — multi-tenant auth, role-based access, and productivity app integrations.

React / TypeScript NestJS / Node.js PostgreSQL Docker REST API

React. Laravel. PostgreSQL. The stack that doesn’t hit a ceiling at $300K ARR.

Industry-standard, investor-legible, infinitely extensible. Investor technical due diligence on a Bubble app ends conversations. This doesn’t.

The stack you build on day one determines what you can do on day 365. No-code tools give you day-one speed and day-365 walls. A production React/Node/PostgreSQL stack gives you a platform that scales as the product scales — and passes technical due diligence at every funding stage.

The total cost of a no-code MVP that hits its ceiling and requires a full rewrite is 2–3x the cost of building on a proper stack from the start. The faster initial cost of no-code is an illusion amortised over the rewrite timeline.

React 18 / TypeScript Laravel (PHP) Node.js PostgreSQL Redis Docker / CI–CD AWS / GCP PostHog Stripe / Paddle Sentry

You’re not choosing a vendor. You’re choosing a risk structure.

The founder who gets burned doesn’t choose a bad agency on purpose. They choose an agency with an ambiguous contract. The comparison is structural.

Offshore dev shop Senior FTE hire No-code (Bubble) ProductQuant Sprint
Price model Time & materials — or “fixed” that becomes T&M on page 3 $150K–$220K/year fully-loaded Platform subscription + rewrite cost later Fixed price in signed contract
Timeline 6–12 months — aspirational, not contractual 3–6 months recruiting before any code written Fast to start, rewrite required at $200K–$500K ARR 8 weeks — contractual
Accountability No recourse when scope isn’t delivered No PM — founder manages the engineer No contractual recourse — platform owns the product Sprint 1 free if we miss scope. In the contract.
PM included Account manager who relays messages Founder is the PM No PM, no engineering team PM owns sprint decisions, not a coordinator
Code quality Variable — junior to mid, minimal documentation One person’s throughput, context dies when they leave Proprietary platform, no real codebase Senior engineers, documented, maintainable by next hire
Scalability Depends on team — often rewrite required One person’s throughput — no surge capacity Hits ceiling at multi-tenancy / complex billing React/Node/PostgreSQL — scales to Series B+
Investor DD Depends on documentation — usually painful Depends on engineer’s documentation habits Bubble app ends the diligence conversation Architecture docs included — non-event at diligence
Ownership Codebase in a zip file — often without docs You own the code — if they documented it Platform owns the product — no IP transfer Source code to your repo from day one

Fixed price. Signed scope. No billing surprises.

Every engagement includes a PM, senior engineers, analytics instrumentation, architecture documentation, and source code transfer. If the first sprint doesn’t deliver the agreed scope, it continues at no charge.

FEATURE SPRINT · 3–4 weeks

Feature Sprint

$15K–$28K

Fixed price · scope agreed in writing before start

One feature. Scoped, built, and shipped in 3–4 weeks. You describe the outcome — we spec it, build it, and hand it over at a fixed price.


  • Written technical spec, signed before development starts
  • Backend, frontend, and integration into existing product
  • Tests on critical paths and architecture documentation
  • Deployment to your infrastructure or AWS/GCP
  • 30-day post-launch warranty

Scope guarantee: Sprint 1 free if we miss the agreed spec.

ONGOING · From 3 months

Embedded Dev Partner

Scoped engagement

PM + engineers working as part of your team

External engineering capacity that slots into your existing product. Two-week sprints, signed acceptance each cycle. You direct the roadmap — we own delivery quality.


  • PM + 2–4 engineers, working as part of your team
  • Two-week sprints, demo and acceptance each cycle
  • Transparent reporting — hours and deliverables
  • Backlog adapts to your priorities each sprint
  • Option to transfer key engineers to your headcount

Clean handover: documented code your engineers can maintain from day one.

Payment structure — App Build Sprint

30%

Deposit on contract signing

30%

Sprint 1 acceptance sign-off

20%

Sprint 2 acceptance sign-off

20%

Sprint 3 (production launch) sign-off

Specificity is the trust signal. Here is the mechanism.

Written spec, signed by both parties

Before we write a line of code. The spec defines exact scope, architecture, acceptance criteria. Not a proposal — a signed document.

Acceptance checklist every sprint

You sign off on each sprint before the next begins. No invoicing without a matching acceptance checklist. No “well, that wasn’t in scope” surprises.

Source code to your repo from day one

You own the code immediately. Not at the end of the engagement — from Sprint 0. If we close tomorrow, the product works and belongs to you.

PM who controls the sprint

You speak to the PM. The PM speaks to the engineers. There is no account manager relaying messages between you and the people building your product.

Free 30-minute scoping session

No obligation, no invoice. The scoping summary belongs to you — take it to any other vendor. We only proceed if the fit is real.

Named stack, verifiable seniority

React, Laravel/Node.js, PostgreSQL. Not “modern tech” — named tools. Not “experienced team” — named engineers with verifiable history.

Your biggest risks, answered.

Architecture documentation is a deliverable, not a post-project negotiation. Every sprint produces: architecture diagram, database schema documentation, API documentation, deployment runbook, environment variable reference, and onboarding notes for your next developer. The documentation requirement is in the written spec before development starts. If it isn’t documented, the sprint isn’t accepted.
Sprint 1 (weeks 3–4). If the deliverables agreed in the signed technical specification for Sprint 1 are not delivered to the acceptance criteria by the end of week 4, the team continues Sprint 1 work at no additional cost until those criteria are met. It does not cover requirements that were not in the signed spec, changes requested after signing, or delays caused by client-side dependencies not being provided on time.
You don’t manage the team. The PM owns the sprint: writes the spec, runs planning and acceptance sessions, controls scope decisions, and is your single point of contact. When a feature request comes in mid-sprint, there is a person who says “this goes on the next sprint, not the current one.” That discipline is what makes the fixed price hold. PM hours are not billed separately — they are included in the sprint price.
Scope changes are discussed between sprints, not within them. Every change is presented with: description, estimated additional time, estimated additional cost. You approve or decline before the next sprint begins. You never receive an invoice for work you didn’t approve. The price for the current sprint does not change once the sprint has started.
Yes. The project repository is set up in your account from Sprint 0. You own the code, the repository, and all IP from the start of the engagement — not at the end. If the engagement ends for any reason, everything built to that point belongs to you. There is no period where we hold the code pending final payment.
Typically 1–2 weeks from the scoping call to Sprint 0 kick-off, depending on how ready you are with context, access, and approvals. The scoping session is free and takes 30 minutes. We send a written estimate and sprint breakdown within 48 hours. If you agree to proceed, we sign the contract and Sprint 0 begins.
Recruiting a senior engineer takes 3–6 months. At $150K–$220K/year fully loaded, you pay whether the MVP ships or not. There is no PM function included — you manage the engineer. When they leave, the context leaves with them. A sprint engagement delivers a working product in 8 weeks, with documentation that lets your next hire onboard without calling the original team. After the sprint, you can hire engineers to maintain a codebase that is already documented and production-grade.

Your B2B SaaS, live in 8 weeks.

Fixed price. Written spec. First sprint guaranteed. Book the free 30-minute scoping session — no commitment, no invoice. Written estimate within 48 hours.

Fixed price. Written spec. First sprint guaranteed. In the contract.