Cairnloop Technologies – Backend / Fintech Software Engineering Intern

Cairnloop Technologies is building technology solutions around digital payments, API integrations, collections, payouts, virtual accounts, reconciliation, and fintech infrastructure .

We are looking for passionate and technically robust interns who want hands-on experience building real-world backend systems and payment workflows.

Role: Backend / Fintech Software Engineering Intern

Location: Gwalior, Madhya Pradesh

Work Mode: On-site

Internship Duration: 3 Months

Students and recent graduates may apply.

What You’ll Work On

REST API development and integration

Payment Collection / Pay-In APIs

Bulk Payout / Disbursement APIs

UPI Collect and payment workflows

IMPS / NEFT / RTGS payment integrations

Virtual Account systems

Webhook processing

Transaction status tracking

Merchant onboarding workflows

Bank and payment gateway integrations

Payment reconciliation systems

Settlement tracking

Transaction ledgers

API authentication and authorization

Secure backend architecture

Admin and merchant dashboard backend services

Production deployment, monitoring and debugging

Technical Skills We’re Looking For

Backend Development

Python / Node.js / Java

FastAPI / Django / Flask / Express.js / NestJS / Spring Boot

RESTful API design

JSON and concepts

API versioning and documentation

Swagger / OpenAPI

Database

Postgre

SQL

/ MySQL

SQL

Database schema design

Transactions and ACID concepts

Indexing and query optimization

Redis / caching concepts

Payment & Fintech Concepts

UPI

IMPS

NEFT

RTGS

Payment gateways

Pay-In / Collection APIs

Payout APIs

Virtual Accounts

Webhooks / callbacks

Settlement and reconciliation

Transaction lifecycle





Idempotency

Double-payment prevention

Ledger systems

Security

OAuth 2.0

JWT

API Keys

HMAC signatures

Request signing

Encryption basics

/ TLS

Role-Based Access Control (RBAC)

Secure credential and secret management

OWASP API Security basics

Development Tools

Git & GitHub

Postman

Linux basics

Docker

CI/CD basics

Logging and debugging

Unit and integration testing

Cloud & Deployment – Good to Have

AWS

EC2 / Lightsail

S3

RDS

Nginx

Domain and SSL configuration

Basic server administration

Docker-based deployment

Strong Preference For Candidates Who Understand

Asynchronous programming

Message queues

Background jobs

Redis queues / RabbitMQ / Kafka concepts

High-concurrency API systems

Rate limiting

API retries and timeout handling

Idempotency keys

Audit logs

Transaction locking

Database consistency

Microservices concepts

WebSocket / real-time systems

What We Value

We are not looking only for certificates.

We value candidates who can:

Understand a problem deeply

Write clean and maintainable code

Learn APIs quickly

Read technical documentation

Debug real production issues

Think about security and reliability

Take ownership of their work

Build systems instead of only copying tutorials

Bonus Skills

Knowledge of:

Banking APIs

Payment gateway APIs

NPCI payment ecosystem

PCI-DSS concepts

Fintech compliance

API security

Reconciliation systems

Accounting / ledger architecture

React / Next.js for basic frontend integration

Who Should Apply?

If you are interested in Backend Engineering, Fintech, Payments, APIs, Banking Technology, Cloud Infrastructure or Distributed Systems , this internship can give you exposure to real-world fintech engineering.

📌 Software Development Engineer Intern (Gwalior)
🏢 Unstop
📍 Gwalior