Senior Backend Engineer — Fintech Credit & Payments Platform

Asystem; New York (NY); On-site; USD 150,000 - 190,000; Full time

Job summary

Arch is hiring a Senior Backend Software Engineer to design, build, and operate core financial systems behind a modern credit and lending platform. You’ll own backend services for credit, payments, and accounting workflows, operating where traditional rails meet crypto infrastructure.

Correctness, observability, and resilience are non-negotiable. You’ll work on money movement, ledgering, and stateful financial systems with high ownership and impact, collaborating with frontend teams using

Qualifications

• 5+ years of backend engineering experience, with direct fintech experience.
• Strong background in credit, lending, or financial systems.
• Hands-on experience with ledgering or accounting-style systems.
• Experience designing event-based systems and asynchronous workflows.
• Deep understanding of idempotency in APIs and distributed processing.
• Strong knowledge of HTTP services and service-to-service communication.
• Production experience with Postgres (schemas, transactions, migrations).
• Experience using Redis in distributed systems
• Comfort operating and debugging production systems.
• Strong systems thinking and attention to correctness and edge cases.

Responsibilities

• Design and implement core backend services for lending, payments, and account state.
• Own and evolve ledgering systems that track balances, interest, and obligations with strong invariants.
• Design event-driven architectures and orchestration workflows across asynchronous services.
• Build idempotent APIs, consumers, and jobs to safely handle retries, replays, and partial failures.
• Model and persist financial data in Postgres, with careful use of transactions and migrations.
• Use Redis for caching, locking, and coordination in distributed workflows.
• Define and evolve service boundaries within a microservices architecture.
• Ensure systems are observable in production via structured logging, metrics, and tracing.
• Operate services end-to-end: deploy, monitor, debug, and improve reliability.
• Collaborate with frontend engineers using Next.js, exposing stable HTTP APIs.
• Contribute to technical design reviews and lift backend engineering quality.

Skills

Backend engineering

Fintech experience

Ledgering systems

Event-driven architectures

Idempotency

HTTP services

Postgres knowledge

Redis usage

Observability

Tools

Postgres

Redis

AWS Lambda

Serverless Framework

Next.js

Job description

Arch is hiring a Senior Backend Software Engineer to design, build, and operate core financial systems behind a modern credit and lending platform. You’ll own backend services for credit, payments, and accounting workflows, operating where traditional rails meet crypto infrastructure.

Correctness, observability, and resilience are non-negotiable. You’ll work on money movement, ledgering, and stateful financial systems with high ownership and impact, collaborating with frontend teams using