Senior Backend Engineer / International Payments

Seedscaler; San Francisco (CA); Hybrid; USD 120,000 - 150,000; Full time

Job summary

A well-funded fintech company in California is seeking a Senior Backend Engineer to lead the development of their backend platform for international consumer finance products. The role involves integrating with third-party providers, owning performance and reliability, and establishing backend standards. Ideal candidates have over 5 years of experience in Python, Go, or Rust, and a solid foundation in financial technology. This is a high-ownership role, perfect for those who want to influence architecture and work in a fast-paced environment.

Qualifications

• 5+ years building and shipping backend web applications in Python, Go, or Rust.
• Strong fundamentals across backend systems, including Postgres, Redis, and AWS.
• Experience designing APIs and shipping production‑grade systems that are reliable and secure.

Responsibilities

• Lead development of a backend platform that serves a REST API for mobile and web clients.
• Integrate with third‑party providers across wallets, banking, authentication, ledgers, and payment rails.
• Own reliability and performance work, including scaling bottlenecks and improving system correctness.

Skills

Backend web applications development

API design

Financial technology experience

Full-stack capabilities

Tools

Python

Postgres

Redis

AWS

Rust

Go

Job description

We’re looking for a Senior Backend Engineer to join a well‑funded, early‑stage fintech company building a consumer finance product for international users. You’ll own core backend systems powering iOS, Android, and web clients, and help set engineering standards as the team scales.

This is a senior, high‑ownership role. You will work closely with technical leadership to build secure, reliable systems that handle real money at scale.

Why consider this role

You want to work on modern financial infrastructure, including cross‑border payments.

You prefer senior, high‑agency teams that ship quickly and iterate in production.

You care about building robust systems with strong security and correctness.

You want meaningful influence on architecture and technical direction.

What you will do

Lead development of a backend platform that serves a REST API for mobile and web clients.

Integrate with third‑party providers across wallets, banking, authentication, ledgers, and payment rails.

Own reliability and performance work, including scaling bottlenecks and improving system correctness.

Establish backend standards (testing, observability, security practices, deployment patterns).

Identify services worth splitting from the monolith for performance or isolation, and implement them.

Technical Stack

• Python (FastAPI) monolith
• Postgres and Redis
• AWS
• Openness to Rust and Go for performance‑sensitive services

What we are looking for

• 5+ years building and shipping backend web applications in Python, Go, or Rust.
• Strong fundamentals across backend systems, including Postgres, Redis, and AWS.
• Experience designing APIs and shipping production‑grade systems that are reliable and secure.
• Experience in financial technology, payments, or regulated environments.
• Full‑stack capability, and a willingness to flex across the stack when needed.