Apply for Backend Engineer Job at Tonic Technologies (Remote)

Applications are invited from interested and qualified candidates to apply for the Backend Engineer Job at Tonic Technologies.

Tonic Technologies Limited is recruiting a Senior Backend Engineer (Node.js) to join its engineering team. The role is fully remote and open to Nigeria-based candidates with strong experience building and maintaining backend systems that support real-world financial transactions.

The successful candidate will work on backend infrastructure powering Tonic Technologies’ consumer products, partner APIs and internal operational tools. The role requires deep experience with Node.js, TypeScript, APIs, databases, webhooks, production monitoring and transaction-sensitive systems.

About Tonic Technologies

Tonic Technologies Limited is an African financial technology company headquartered in Lagos, Nigeria. Founded in 2019, the company develops digital payment infrastructure and consumer web products covering monetary transfers, payment remittances and e-commerce transactions.

The company says its products serve more than 1.5 million users across Nigeria, Ghana, Uganda, the United States and the United Kingdom.

The Backend Engineer will work on systems where reliability, security and accurate transaction processing are critical.

What the Backend Engineer Will Do

The successful candidate will build and maintain backend systems supporting Tonic Technologies’ consumer, partner and internal products.

Key responsibilities include:

Developing and maintaining backend services used by the company’s iOS, Android and web applications.
Supporting products including wallets, gift cards, Virtual Dollar Cards, bills, gadgets and eSIM services.
Building and maintaining APIs used by merchants and developers through the company’s Gift Card API.
Supporting internal administrative tools used by Operations teams.
Designing reliable and well-structured APIs for frontend, mobile, partner and administrative applications.
Improving database queries and backend performance under load.
Handling payment-partner webhooks and ensuring duplicate, delayed or incorrectly ordered events do not compromise transaction accuracy.
Managing backend flows involving payments, wallet funding, withdrawals, KYC, exchange rates and card funding.
Working with transactions involving Naira, US dollars and Ghanaian cedi.
Ensuring backend services are properly deployed, monitored and maintained in production.
Working with containerised services and Kubernetes-based infrastructure.
Collaborating through GitHub pull requests and code reviews.
Monitoring production systems and responding to issues when they occur.
Maintaining security controls around authentication, access, secrets, customer data and audit trails.

Technology Stack

The role involves working with technologies and development practices including:

Node.js
TypeScript
JavaScript
Express and/or NestJS
REST APIs
Webhooks
Docker
Kubernetes
Argo CD
Sentry
Yarn
ESLint
Prettier
Husky
Conventional commits
GitHub pull requests

Candidates should also understand when to use database indexing, queues and transactions when designing backend systems.

Qualifications and Requirements

Applicants should have:

At least 6 years of experience building backend systems with Node.js.
Strong TypeScript development skills.
Practical understanding of idempotency, retries, race conditions and database transactions.
Experience integrating third-party APIs and webhooks.
Experience dealing with unreliable external services, including duplicate requests, timeouts and delayed responses.
An understanding of production monitoring, logs, alerts and metrics.
Ability to explain technical decisions and trade-offs to non-technical stakeholders.
A strong approach to security, authentication, access control, secrets management and audit trails.
Experience using AI-assisted development tools while maintaining responsibility for reviewing generated code.
Commitment to protecting customer data and confidential information when using AI tools.

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Additional Experience That Will Be an Advantage

The following experience will be beneficial:

Previous experience in fintech or payments.
Experience building ledger or wallet systems using double-entry bookkeeping.
Experience with card issuing, virtual accounts or stablecoin payment rails.
Experience designing public APIs for external developers.
Familiarity with Kubernetes manifests or Argo CD deployments.
Experience handling production incidents and preparing post-mortems.

Who Tonic Technologies Is Looking For

This role is suited to an engineer who is comfortable working on existing production systems rather than only developing new services.

Candidates should understand that backend engineering in a financial technology environment requires careful attention to reliability, testing, monitoring and transaction integrity.

The successful candidate should be comfortable investigating issues that can affect customers’ money and designing systems that remain accurate when requests are repeated, payment partners fail or services experience unexpected delays.

Benefits

Tonic Technologies states that the successful candidate will receive:

Fully remote work from Nigeria.
HMO.
Annual leave.
Work equipment.
Learning budget.
Opportunity to build systems supporting transactions for more than one million users.
Exposure to high-volume financial technology systems.
Collaboration with engineering and Operations teams.

How to Apply for the Backend Engineer Job at Tonic Technologies

Interested and qualified candidates should apply through the application link provided by Tonic Technologies.

Applicants should be prepared to provide a GitHub profile or portfolio and answer a short question about a production bug or incident they experienced, including how they resolved it.

The company says it is particularly interested in practical examples involving production failures, duplicate transactions, financial systems or emergency fixes.

Frequently Asked Questions

What position is Tonic Technologies recruiting for?

Tonic Technologies is recruiting for a Senior Backend Engineer (Node.js) position.

Is the Tonic Technologies Backend Engineer job remote?

Yes. The position is described as fully remote for Nigeria-based candidates.

How much experience is required?

The stated requirement is 6+ years of experience building backend systems with Node.js.

What programming technologies are required?

The role requires strong experience with Node.js and TypeScript, with experience around REST APIs, webhooks and production backend systems. The listed stack also includes Express and/or NestJS, Docker, Kubernetes and Argo CD.

Is fintech experience required?

Fintech experience is listed as a bonus rather than an absolute requirement. Experience with payments, wallets, ledgers, card issuing, virtual accounts or stablecoin rails can strengthen an application.

What qualifications are required?

The job specification lists BA/BSc/HND among the required qualifications, alongside the technical experience and skills outlined in the vacancy.

What is the deadline for the application?

No application deadline was specified in the vacancy.

How do applicants apply?

Interested candidates should use the application button provided in the vacancy and be ready to submit a GitHub profile or portfolio and answer the production-incident question.