Full-Stack Engineer - Payments & Transactions Platform

SharpStakes; Toronto; On-site; CAD 90,000 - 130,000; Full time

Job summary

SharpStakes, a fast-growing tech company, seeks a hands-on Full-Stack Engineer to build and maintain a new transaction‑driven consumer platform. You will work across backend services and React frontend, integrating third‑party APIs and ensuring reliable data movement between systems.

You’ll design relational data models, write secure REST APIs, and implement robust transaction handling with proper isolation.

Qualifications

• 3–5 years of professional software engineering experience
• Production experience using TypeScript across backend services and React frontends
• Strong SQL skills and relational data modelling
• Experience with database transactions, isolation levels, locking, and migrations
• Experience designing, building, and maintaining REST APIs
• Experience integrating third‑party APIs and webhooks in production
• Understanding asynchronous integration failure modes: retries, timeouts, duplicates, delays, out‑of‑order delivery
• Experience designing idempotent operations and protecting data consistency
• Experience writing automated tests for backend and frontend functionality
• Clear written communication, especially to non‑engineering stakeholders
• Comfort in a fast‑moving environment where priorities evolve

Responsibilities

• Develop backend services using TypeScript, Node.js, Express, and PostgreSQL
• Build responsive consumer experiences with React and TypeScript
• Design and maintain relational data models and migrations
• Build secure REST APIs connecting frontend, backend, and external platforms
• Integrate third‑party APIs, SDKs, payments, identity services, and webhooks
• Implement account, authentication, balance, transaction, deposits, and withdrawals
• Ensure data integrity with transactions, locking, and idempotency
• Write automated tests for critical workflows
• Debug across applications, databases, APIs, and providers
• Contribute to deployment, monitoring, and documentation
• Communicate technical work to engineers and non‑engineers

Skills

TypeScript

React

SQL

REST APIs

Testing

Tools

PostgreSQL

Docker

Supabase

GitHub Actions

FastAPI

Job description

SharpStakes, a fast-growing tech company, seeks a hands-on Full-Stack Engineer to build and maintain a new transaction‑driven consumer platform. You will work across backend services and React frontend, integrating third‑party APIs and ensuring reliable data movement between systems.

You’ll design relational data models, write secure REST APIs, and implement robust transaction handling with proper isolation.