Senior Node.js/NestJS Engineer - FinTech Backend (Remote)

Fintech Core; Wilmington (NC); Remote; USD 140,000 - 180,000; Full time

Benefits offered by this job

Billable days off

Remote work mode

Flexible schedule

Competitive pay

Friendly team

Job summary

Fintech Core is seeking a Senior Backend Engineer (NodeJS/NestJS) to join an outsourced team on a production fintech platform focused on business accounting and financial management. You will extend and improve features, including banking integrations, reconciliation, and analytics, in a distributed, event-driven environment.

The role requires strong TypeScript/Node.js production experience, NestJS, and readiness to work with Kotlin/Spring Boot.

Qualifications

• 5+ years of backend development in production environments.
• Strong knowledge of Node.js and TypeScript in production systems.
• Experience with NestJS and REST API design.
• Readiness to work with Kotlin/Spring Boot in a mixed Kotlin/JS backend ecosystem.
• Strong SQL/data modeling and database performance skills.
• Experience with messaging/event-driven architectures and distributed systems.

Responsibilities

• Develop backend functionality with TypeScript and NestJS within the existing architecture.
• Extend the BFF layer with APIs and business logic for new financial features.
• Design REST APIs contracts using OpenAPI.
• Integrate new functionality without breaking current behavior; improve existing components.
• Support integration between NestJS and Kotlin services and external systems.
• Build and extend integrations with banking providers and accounting systems (e.g., Odoo).
• Develop transaction-processing and reconciliation workflows; handle partial payments, duplicates, retries, concurrency.
• Implement event-driven communication and scheduled/async workflows.
• Ensure data consistency across APIs, services, and analytics.
• Implement tenant-aware authorization and access control.
• Apply idempotency, safe retries, version checks, and proper transaction boundaries.
• Improve observability with logging, metrics, health checks, and alerts.
• Investigate production issues and implement fixes.
• Write clean, testable code with unit/integration tests for financial logic and authorization.
• Participate in code reviews, CI/CD, and API/architecture documentation.
• Take features from analysis to release with BA/PM/QA/client teams.

Skills

Node.js

TypeScript

NestJS

REST APIs

SQL

Event-driven

CI/CD

Git

Testing

Security

Independent work

FinTech

English B2/C1

Tools

PostgreSQL

Docker

Kubernetes

OpenAPI

Keycloak

Cerbos

AWS SQS/SNS

Temporal

Job description

Fintech Core is seeking a Senior Backend Engineer (NodeJS/NestJS) to join an outsourced team on a production fintech platform focused on business accounting and financial management. You will extend and improve features, including banking integrations, reconciliation, and analytics, in a distributed, event-driven environment.

The role requires strong TypeScript/Node.js production experience, NestJS, and readiness to work with Kotlin/Spring Boot.