Field notes from production.

Payments · 8 min read

Stripe to Stripe migration: moving between Stripe accounts

How to move customers, payment methods, and live subscriptions between Stripe accounts: what Stripe copies for you, what it does not, ID remapping, and zero-downtime cutover.

Payments · 7 min read

QuickPay to Stripe migration: the small-PSP playbook

Migrating from QuickPay to Stripe: subscription token export from a smaller PSP, Nordic payment methods, and the process realities when your provider rarely does migrations.

Payments · 7 min read

Checkout.com to Stripe migration: the enterprise path

Moving from Checkout.com to Stripe: instrument export, network tokens, multi-entity processing, 3DS continuity, and cutover sequencing for subscription businesses.

Payments · 7 min read

NMI to Stripe migration: leaving the Customer Vault

Migrating from NMI to Stripe: Customer Vault token export, multi-MID consolidation, ACH details, and rebuilding recurring billing on Stripe rails.

Payments · 8 min read

PayPal to Stripe migration: agreements, not tokens

Moving PayPal subscriptions to Stripe: when billing agreements transfer, when they cannot, and how to run a re-consent campaign that keeps your subscribers.

Payments · 8 min read

Braintree to Stripe migration: what actually moves

Migrating from Braintree to Stripe: vault export mechanics, why Braintree-vaulted PayPal is the hard part, rebuilding subscriptions, and cutting over with zero downtime.

Payments · 14 min read

Adyen to Stripe migration: the complete guide

How to move live subscriptions from Adyen to Stripe with zero downtime: re-tokenization, mandate takeover, cutover sequencing, and reconciliation — from the engineer who moved $100M+ for Babbel.

Billing · 9 min read

Failed payments and dunning: recovering subscription revenue

Involuntary churn is the quietest revenue leak in SaaS. Retry timing, card updaters, dunning emails that convert, grace states, and the metrics that tell you whether recovery is actually working.

Billing · 8 min read

Stripe Billing vs Recurly: an engineer's comparison

Recurly's retention machinery vs Stripe Billing's platform gravity: where each wins, the migration cost between them, and how to choose based on where your revenue actually leaks.

Billing · 8 min read

Stripe Billing vs Chargebee: an engineer's comparison

From an engineer who migrates billing systems for a living: where Chargebee's billing layer earns its fee, where Stripe Billing is enough, and the switching costs nobody prices in.

Billing · 8 min read

Chargebee to Stripe Billing migration: state, not cards

Leaving Chargebee for Stripe Billing: why your cards may already be on Stripe, migrating mid-cycle subscription state, coupons, credits, and dunning without billing anyone twice.

Billing · 8 min read

Recurly to Stripe migration: vault plus billing state

Migrating from Recurly to Stripe Billing: exporting the Recurly vault, mapping plans and mid-cycle state, and cutting over at renewal boundaries with zero downtime.

Marketplaces · 8 min read

Chargebacks on marketplaces: who eats the loss?

A dispute against a split payment unwinds money that already left: how marketplaces assign liability, hold reserves, fight evidence battles, and reverse ledger entries without stiffing sellers or absorbing every loss.

Marketplaces · 9 min read

In-app wallets and ledgers: marketplace bookkeeping that survives

Double-entry ledgers for marketplace wallets, escrow, and balances: the invariants that keep in-app money honest, the anti-patterns that create phantom balances, and reconciliation against your processor.

Marketplaces · 8 min read

Marketplace payouts: rails, FBO accounts, and tax forms

How marketplaces actually pay sellers: payout rails compared, what an FBO account structure does for money-transmission and tax exposure, and where 1099 reporting lands.

Marketplaces · 9 min read

Stripe Connect vs custom marketplace payments

When Stripe Connect is the right marketplace payment stack, and when a custom build (processor + ledger + payout rail) earns its complexity: fees, control, compliance, and the real operational cost of each path.

Code quality · 7 min read

Taking a Cursor-built app to production safely

Cursor writes across your whole repo — which is exactly why its failure modes differ from app builders. Consistency drift, silent rewrites, test theater, and the production checklist for Cursor-built codebases.

Code quality · 7 min read

Taking a Bolt or v0 app to production safely

Bolt and v0 excel at frontends — which means the biggest production risk is the backend that mostly is not there. What to verify, what to build for real, and when the prototype should stay a prototype.

Code quality · 7 min read

Taking a Lovable app to production safely

Your Lovable app works. Before real users and real money: the RLS policies to verify, the edge-function checks, and the readiness list specific to Lovable's Supabase-centric stack.

Code quality · 10 min read

Is your AI-built app safe to launch? The 10-point checklist

Ten checks that catch the failures AI-generated codebases actually ship with: client-side price trust, missing webhook idempotency, UI-only authorization, committed secrets, and more — each with a fast way to verify it yourself.

Code quality · 10 min read

Technical due diligence checklist for startup deals

The technical due diligence checklist I use: code and architecture, team and process, security posture, payment integrity, and the questions that surface what a data room hides.

Code quality · 9 min read

Taking over a codebase from an agency: the playbook

Leaving your agency or bringing development in-house: the access checklist, the handover deliverables to demand, the review that tells you what you actually received, and how to keep shipping through the transition.

Code quality · 8 min read

The questions to ask before (and while) paying an agency

The contract-time and invoice-time questions that keep you owning what you pay for: source control, deploy access, migrations, tests as deliverables, and the independent-review clause agencies hate and good ones accept.

Code quality · 9 min read

How much does a code audit cost?

Real price ranges for code audits and technical reviews in 2026: what $500, $5,000, and $50,000 actually buy, what drives the price, and the red flags that mean you are overpaying.

AI delivery · 9 min read

AI-augmented development: how an agent fleet ships production code

How I run a fleet of AI coding agents (Claude Code, Codex) that plans, builds, reviews, and ships production software with human-in-the-loop control: the architecture, the gates, and what actually makes it safe.