I will build or fix your backend API

J
joshuawaiswa
J
joshuawaiswa
joshuawaiswa

About this gig

Your API is the backbone of your product. I'll make it reliable, fast, and ready for production.


I'm a senior software engineer with 10+ years building and scaling backend systems for fintech, B2B SaaS, and ecommerce products. I've shipped APIs that handle real money (Stripe webhooks), high traffic (~1M SMS/day), and complex business workflows and I know what breaks when you move from prototype to production.


What I can help with:

  • Design and build REST APIs from scratch (Rails, Node.js, FastAPI)
  • Fix bugs, refactor legacy code, and modernize outdated backends
  • Integrate third-party services: Stripe, Algolia, NetSuite, external APIs
  • Add background jobs, event-driven workflows, and webhook handlers
  • Set up authentication, authorization, and secure data handling
  • Write unit and integration tests (RSpec, pytest, Jest)
  • Deploy to AWS with CI/CD pipelines


Why work with me:

  • I own delivery end-to-end from requirements to release
  • Clear communication, async-friendly, remote-first
  • I ask the right questions before writing code
  • Production-minded: logging, error handling, and test coverage included


Message me before ordering so I can confirm scope and recommend the right package.

Get to know joshuawaiswa

joshuawaiswa
  • FromUganda
  • Member sinceFeb 2019
  • Avg. response time1 hour
  • Last delivery6 years
  • Languages

    English
I am a Software engineer with more that 7 years experience working on different projects. I have collected valuable knowledge working as a Team leader, working on Unix systems, Agile software engineering, Scrum, providing advice and a lot more. Over the past few years, I've developed a niche in Fintech building Blockchain applications, Different exchanges and managing Unix servers. Am great at what I do and deliver to the satisfaction of my clients.

My Portfolio