Senior Full-Stack Engineer (Python / React) US or Canada only

Зарплата: $5000–$6000

Location: candidates must be physically based in the US or Canada, with the right to work there. Full overlap with Central Time (US) business hours.
Format: long-term contract, full-time
Rate: $3035/h (contractor, net)
Start: earlymid December 2026

About the project
A US fintech/payments SaaS company is looking for a Senior Full-Stack Engineer to join a very small product team. The product is an AI-driven platform that helps subscription merchants recover failed payments. You will work directly with the lead engineer, with minimal hand-holding.

What you will do
– Build frontend features in React / Next.js (deployed on Vercel)
– Build backend services in Python / FastAPI (microservices on AWS), including new payment provider integrations
– Integrate external services (payment processors, email delivery) – Work with the product's AI components on the integration level – Cover merchant requests and support tasks with the lead engineer
– Write your own automated tests

Requirements
– 5+ years of full-stack experience
– Strong React and Next.js
– Solid Python (FastAPI or similar)
– Microservices on AWS, CI/CD basics
– Experience integrating LLM / AI services into a product
– Fluent, confident spoken English: you will talk to the team and merchants daily
– Self-sufficient, clear written communication, calm with on-call style interruptions

Nice to have
– Payments / PSP integrations (Stripe, Braintree, Adyen)
– Temporal or other workflow orchestration

Hiring process Screening call technical interview client interview possible short take-home (34 h) contract.