ONE CUSTOM PAYMENT API INTEGRATION, ACROSS STRIPE, AUTHORIZE.NET & PAYPAL
I'm Ajeet Kumar. I build the payment API integration layer SaaS teams put in front of Stripe, Authorize.Net, PayPal and other providers — so your product talks to one internal API and you can add, switch, or route between SaaS payment gateways without rewriting your billing logic.
Your SaaS Payment Architecture
Three Provider Integrations, Zero Coherence
Most SaaS payment stacks grow one provider at a time. Stripe first, then Authorize.Net for a US enterprise deal, then PayPal because a big customer insists. Each integration ships as its own island, with its own webhook handler, its own retry rules, its own quirks leaking into product code.
Payment API unification is the fix — a single internal layer the rest of your system can rely on.
What I Build
Payment API Integration & Orchestration Done Right
Custom SaaS financial technology built the way payment systems need — provider-agnostic, observable, safe to change, and designed for the failure paths that hurt revenue.
What You Get
A Payment Stack That Stops Fighting Your Roadmap
The point of payment API unification isn't elegance — it's that adding, switching, or routing between SaaS payment gateways stops being a project.
How I Build It
I Design for the Failure Paths First
Payment failures are silent. A webhook that never arrives throws no error. A gateway degradation looks exactly like a spike in declines. By the time anyone notices, the revenue is already gone. So I design for the failure paths first.
Who I Work With
SaaS Teams Who Have Outgrown a Single-Provider Setup
SaaS founders whose payment integration has outgrown a single-provider setup
CTOs handling multiple currencies, regions or local payment methods
Teams planning a Stripe → Authorize.Net (or the reverse) migration without downtime
SaaS financial technology teams building embedded payments into their product
Founders who could build this themselves but want engineering time going into the product
How I Work
Working Software, Not Proposals
Phased Delivery
A scoped first phase — small, independently useful, delivered quickly. You judge working software rather than a proposal, then decide on the next phase.
Honest Scoping
If an existing connector or no-code orchestrator covers part of what you need, I'll tell you. Custom payment API integration is for the parts where accuracy and edge cases genuinely have to be guaranteed.
You Own What I Build
Hosting sits in your account. Documentation is written so another developer can pick it up. I build systems clients can maintain, not dependencies on me.
Direct Senior Attention
You work directly with me — the engineer building your integration — not an account manager relaying messages to a junior team.
Experience
17+ Years Building Payment & Integration Systems
For clients across the US, UK, Europe and Australia. My payment API integration work spans Stripe, Authorize.Net and PayPal, with recurring and subscription billing, WooCommerce, and API integration with HubSpot and accounting platforms.
17+
Years building payment & backend systems
3+
Gateways: Stripe, Authorize.Net, PayPal
1,000+
Monthly recurring clients on one build
~90%
Admin effort reduced vs manual process
Recent Work
A complete recurring billing infrastructure on Authorize.Net for an agency managing over 1,000 monthly recurring clients — tokenised payments, subscription lifecycle, webhook automation with idempotency, failed-payment recovery, reconciliation, and API integration with HubSpot for consistent customer data.
Replaced a manual process · ~90% less administrative effort
Ready to Unify Your Payment Integrations?
Tell me which providers you're running today and where the seams are showing. I'll tell you honestly what payment API integration work is worth doing, what an off-the-shelf orchestrator can still handle, and where your current setup is most likely to fail quietly.
No pitch. If you don't need me, I will say so.