Field notes from the build

A product engineering blog for software that must work

Concrete lessons from production MVPs, rescue work, payments, AI-built apps, and white-label delivery. Written by the people doing the engineering.

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First four guides

Start with the problem in front of you

9 min readJuly 19, 2026

Guide 01

Why your Lovable app's payments look successful but record nothing

A practical diagnosis for Lovable app broken payments where Stripe charges the customer but no order, subscription, or database record appears.

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10 min readJuly 19, 2026

Guide 02

What to do when your AI-built app breaks in production

A calm production triage plan for deciding whether to repair or rebuild an AI-generated app made with Lovable, Bolt, v0, or similar tools.

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9 min readJuly 19, 2026

Guide 03

White-label development: how agencies ship without hiring engineers

How to choose and run a white label development partner for agencies, including scope, NDA, margins, client communication, delivery, and handover.

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10 min readJuly 19, 2026

Guide 04

How much an MVP really costs in 2026: our fixed prices explained

A concrete 2026 MVP cost guide covering HyperBrain Labs' $3,999 Production MVP, custom fixed quotes, retainers, scope, ownership, and third-party costs.

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12 min readJuly 26, 2026

Guide 05

The MVP architecture decisions that decide whether you survive 50,000 users

Which architecture decisions in a first version are cheap to make and expensive to reverse. Tenancy, identity, money, and background work, from a build that reached 50,000+ users across 20+ cities.

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10 min readJuly 26, 2026

Guide 06

How we ship in 21 days and still run a business fixing other people's shortcuts

Fast delivery is a scoping decision, not an engineering one. What we compress, what we never compress, and what running an app rescue practice teaches you about the real causes of technical debt.

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