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Fiverr Pro
English
$
USD
I will build secure subscription billing systems using stripe or paypal
Kartike Singh
Level 2
5.0
5.0
About this gig
We design and build production-ready subscription billing systems using Node.js + TypeScript, focused on security, reliability, and scalability.
This service is for SaaS founders, startups, and businesses that need real billing infrastructure, not basic payment buttons.
What we build:
- Secure Stripe & PayPal integration
- Recurring subscriptions (monthly / yearly / custom)
- Trials, coupons & promotional logic
- Webhook-based automation
- Payment retries & smart failure handling
- Invoice & receipt automation
- Subscription lifecycle flows (upgrade, downgrade, pause, cancel)
- Customer billing dashboards
- Clean, maintainable backend architecture
Tech stack:
Node.js, TypeScript, Express / NestJS, Stripe SDK, PayPal APIs, Webhooks, PostgreSQL / MongoDB
Why work with us:
- Production-grade code, not scripts
- Secure architecture & best practices
- Clean documentation
- Fast communication
- Built for scale from day one
If you're building a SaaS or upgrading your billing stack, well design a secure, scalable billing system that wont break when you grow.
Message us before ordering so we can review your requirements and design the right solution.
Get to know Kartike Singh
Kartike Singh
Building softwares for making life easier
Level 2
- FromIndia
- Member sinceJul 2020
- Avg. response time1 hour
- Last delivery2 weeks
Languages
Hindi, English
Hello Kartike here!
I have more than 5 years of experience with software development which includes but is not limited to APIs, websites, backend servers etc!
Feel free to contact me to help turn your ideas into reality!
My Portfolio
FAQ
Can you handle complex subscription logic?
Yes. Including plan upgrades, downgrades, proration, retries, coupons, trials, cancellations, and reactivations.
Can you integrate this into my existing SaaS?
Yes. We work inside your existing codebase and architecture.
Can you migrate us from old billing systems?
Yes. We handle migrations from: - Manual billing - Razorpay - Old Stripe versions - Custom billing systems
Do you provide webhook automation?
Yes. Webhooks are essential for proper subscription lifecycle handling, and We implement them properly.
Will this be secure and production-ready?
Yes. Security, idempotency, retries, and webhook verification are standard in our builds.
Can you build customer billing dashboards?
Yes. Full dashboards with invoices, subscriptions, payment history, upgrades, cancellations.
Can you handle SaaS + marketplace billing?
Yes. Including: - Platform fees - Split payments - Creator payouts - Commission logic
Reviews
7 reviews for this Gig
| (7) | ||
| (0) | ||
| (0) | ||
| (0) | ||
| (0) |
Rating Breakdown
- Seller communication level
- Recommend to a friend
- Service as described
Sort By
Most relevant
A 
anthonyscarr
Repeat Client
United Kingdom
We love working with Kartike. No bs he is one of the best people I have had the pleasure of working with.
$50-$100
Price
6 days
Duration
Helpful?O 
osh_nft
Repeat Client
Japan
I had an amazing experience working with kartikethehuman on Fiverr! Very professional, knowledgeable, and delivered the project on time. The communication was excellent and they went above and beyond to ensure that I was satisfied with the final product.
Helpful?E 
eduardo1990s
Portugal
This seller did exactly what I asked of him and was very communicative and thoughtful in the process. I will come back.
K 
Seller's Response
Helpful?A 
avneeshlegends
Repeat Client
United States
Amazing seller! He's very polite and understanding, also very fast in delivering the work. Will 100% recommend to anyone that wants a custom bot. Will definitely be working with him in the future.
K Seller's Response
Helpful?S sasan369
India
perfect! exactly what we needed. Thank you!
K Seller's Response
Helpful?
Reviews
7 reviews for this Gig
| (7) | ||
| (0) | ||
| (0) | ||
| (0) | ||
| (0) |
Rating Breakdown
- Seller communication level
- Recommend to a friend
- Service as described
Sort By
Most relevant
A anthonyscarr
Repeat Client
United Kingdom
We love working with Kartike. No bs he is one of the best people I have had the pleasure of working with.
$50-$100
Price
6 days
Duration
Helpful?O osh_nft
Repeat Client
Japan
I had an amazing experience working with kartikethehuman on Fiverr! Very professional, knowledgeable, and delivered the project on time. The communication was excellent and they went above and beyond to ensure that I was satisfied with the final product.
Helpful?E eduardo1990s
Portugal
This seller did exactly what I asked of him and was very communicative and thoughtful in the process. I will come back.
K Seller's Response
Helpful?A avneeshlegends
Repeat Client
United States
Amazing seller! He's very polite and understanding, also very fast in delivering the work. Will 100% recommend to anyone that wants a custom bot. Will definitely be working with him in the future.
K Seller's Response
Helpful?S sasan369
India
perfect! exactly what we needed. Thank you!
K Seller's Response
Helpful?
