Senior Node.js Backend Engineer
Job Description
Tonic Technologies Limited, a Nigerian fintech company, is hiring a Senior Node.js Backend Engineer to build dependable systems for payments, wallets, gift cards, digital cards and other financial products used across Africa. This is a senior technical opportunity for an engineer who understands that financial software must be reliable, secure, observable and resilient when handling real customer transactions.
Key Responsibilities
- Build and maintain APIs serving web, mobile, partner and internal applications.
- Improve reliable flows for payments, wallet funding, withdrawals, KYC, rates and card services.
- Design systems that handle retries, duplicate requests, webhooks and transaction failures safely.
- Support integrations with payment, banking and card partners.
- Improve query performance, monitoring, logging and production reliability.
- Work with containerised services and deployment workflows using Docker, Kubernetes and Argo CD.
- Collaborate with product, operations and frontend teams to deliver secure, maintainable solutions.
Key Requirements
- Strong professional experience building backend systems with Node.js and TypeScript.
- Practical knowledge of APIs, database transactions, idempotency, retries and race conditions.
- Experience integrating third-party services and handling unreliable webhooks.
- Comfort with testing, code review, observability and production incident response.
- Awareness of authentication, access control, secrets management and customer-data protection.
- Fintech, payments, wallet, ledger, card or public API experience is an advantage.
