Payment integration
Payments fail in boring, expensive ways: duplicated charges, missed webhooks, subscriptions that drift out of sync with entitlements. We build the integration with idempotency, webhook verification, retry handling and a reconciliation path, so finance and engineering see the same numbers.
What you get
The outcomes we hold ourselves to on this work. If we cannot commit to them for your project, we say so during scoping rather than after the invoice.
- Idempotent charge handling — no double billing under retries
- Verified, replay-safe webhooks with a dead-letter queue
- Subscription state that matches product entitlements
- PCI-conscious design: card data never touches your servers
Deliverables
Everything on this list is handed over and documented. Anything outside it is quoted before it is built.
- Checkout / payment element integration
- Subscription plans, trials, proration and dunning
- Webhook handlers with signature verification and retries
- Invoices, receipts and refund flows
- Reconciliation reports and admin tooling
- Sandbox test suite covering failure paths
Typical timeline
Most engagements of this type run 1–4 weeks end to end. Step four absorbs the difference between the short and long end of that range.
Discovery call
30 minutes, freeWe walk through what you are building, who it is for, and what has to be true for the project to count as a success. You leave with a rough scope, a rough number and an honest read on whether we are the right team.
You receive: Written scope summary within 24 hours
Proposal & fixed scope
2–3 daysA written proposal: milestones, deliverables, timeline, price and explicit exclusions. No hourly surprises — you approve a scope, and changes to it are quoted before any work starts.
You receive: Proposal, contract and milestone schedule
Architecture & design
Week 1Data model, API contracts and infrastructure plan on paper before code. UI work starts in Figma so you approve screens rather than reviewing half-built pages.
You receive: Architecture doc, ER diagram, approved designs
Build in weekly sprints
Bulk of the projectWorking software every week on a staging URL you can click through. A short written update each Friday: what shipped, what is next, anything blocking. You are never guessing where the project stands.
You receive: Staging environment, weekly demo and written update
Test, harden & launch
Final 1–2 weeksAutomated tests in CI, load and failure-path testing, security review, performance budgets, then a rehearsed deploy with a rollback plan. Launch day is uneventful by design.
You receive: Test suite, CI pipeline, production deployment
Handover & support
OngoingDocumentation, a recorded walkthrough and a 30-day warranty on everything we shipped. If you want us to keep operating it, a maintenance retainer picks up from there.
You receive: Docs, walkthrough video, 30-day warranty
Questions we get asked
- Which providers do you work with?
- Stripe most often, plus PayPal, Razorpay, Paddle and Lemon Squeezy. For regional processors we work from their API docs and sandbox.
- Do you handle PCI compliance?
- We design so card data never reaches your infrastructure — hosted fields and provider-side checkout — which keeps you in the lightest SAQ tier. We are not a compliance auditor and will tell you when you need one.
Where this has shipped
Case studies with the numbers we measured, including the ones that did not move.
AK Car Rental
A car rental booking platform — accounts, a vehicle catalogue, and a booking form that captures type, locations and dates in a single pass.
Client projectRead case study
MHB AC Repair & Services
A service business site built around one job: turn a visitor into a booked call-out, on a phone, in under a minute.
Client projectRead case study
Fashion Storefront
A clothing storefront with category browsing, a cart that survives navigation, and a best-sellers carousel on the landing page.
Client projectRead case study
Usually paired with this
Most projects combine two or three of these. We scope them as one engagement rather than separate invoices.
End-to-end web applications
Full product builds — from empty repo to live, monitored deployment.
4–12 weeksFrom $96
Android & iOS applications
Cross-platform mobile apps that ship to both stores from one codebase.
6–16 weeksQuoted per project
RAG systems & knowledge assistants
Retrieval pipelines that answer from your data, with citations.
3–10 weeksFrom $108
Need payment integration?
Tell us what you are working with — existing code, a blank repo, or a deadline you are worried about. This one is quoted per project: you get a written scope and a fixed number within 24 hours.
Replies within 4 business hours · No obligation · You keep the scope document