Back End Developer

Backend Developer JD:-

Purpose of Role:-

The Backend Developer is responsible for designing, building, and maintaining scalable, secure, and high-performance server-side systems that power the organization's digital products. The role focuses on developing reliable backend services, APIs, business logic, database solutions, payment integrations, and third-party integrations across the platform.

The Backend Developer will primarily work with Python and FastAPI, while also having sufficient knowledge of .NET / ASP.NET Core to understand, manage, troubleshoot, and make required changes to existing .NET-based applications and services.

The role ensures that backend services are robust, well-architected, secure, maintainable, and capable of supporting business growth and increasing transaction volumes.

Accountability & Responsibilities of Role:-

1. Service Development & Ownership:-

• Design, develop, and maintain scalable backend services and applications using Python and FastAPI.

• Build and maintain RESTful APIs and backend services for internal and external applications.

• Work with existing .NET / ASP.NET Core applications and have sufficient knowledge to understand, manage, troubleshoot, and implement required changes.

• Develop database-driven services and business logic using appropriate backend technologies.

• Design scalable, secure, and maintainable server-side solutions aligned with business requirements.

• Design and optimize database schemas, queries, indexes, and stored procedures.

• Take ownership of backend services from development and testing through deployment, monitoring, and maintenance.

2. Database & Data Processing:-

• Work extensively with SQL databases such as SQL Server, PostgreSQL, MySQL, or similar technologies.

• Work with NoSQL databases such as MongoDB, Redis, DynamoDB, or similar technologies.

• Develop and optimize complex SQL queries and database operations.

• Handle database performance optimization, indexing, transactions, and data integrity.

• Use Pandas and NumPy for data processing, transformation, manipulation, and automation-related tasks.

• Design efficient data models based on application and business requirements.

3. API, Payment & Third-Party Integration:-

• Design and develop secure and reliable RESTful APIs.

• Integrate and maintain multiple payment gateways and payment-related services.

• Handle complete payment workflows including payment initiation, verification, transaction status, callbacks/webhooks, refunds, failed transactions, reconciliation, and idempotency.

• Integrate third-party APIs and external services with appropriate error handling and security practices.

• Ensure proper authentication, authorization, validation, and API security.

• Troubleshoot and resolve API, payment, and third-party integration issues.

4. Code Quality, Security & Collaboration:-

• Write clean, reusable, well-documented, and testable code following established coding standards.

• Follow OOP, SOLID principles, design patterns, and clean architecture wherever applicable.

• Participate in code reviews, sprint planning, technical design discussions, and architecture discussions.

• Collaborate with Frontend, QA, DevOps, Product, and other engineering teams.

• Maintain clear technical documentation for backend services, APIs, integrations, and databases.

• Follow security best practices for APIs, databases, authentication, authorization, and sensitive transaction data.

5. Performance, Reliability & Production Support:-

• Ensure backend applications and services meet required standards for performance, scalability, security, and reliability.

• Troubleshoot, debug, and resolve production issues across application, API, database, payment, and integration layers.

• Identify and resolve performance bottlenecks and recurring production issues.

• Contribute to root-cause analysis and incident resolution.

• Support application monitoring, logging, error handling, and production maintenance.

• Identify technical debt and recommend improvements to improve system stability and maintainability.

6. Automation, AI & Continuous Improvement:-

• Use Python for scripting, automation, data processing, and integration-related tasks where required.

• Exposure to AI/ML concepts, tools, or APIs is a plus.

• Stay updated with relevant developments in Python, FastAPI, .NET, databases, and backend technologies.

• Recommend and adopt tools, libraries, and architectural improvements that improve development efficiency, system reliability, and scalability.

• Contribute to shared libraries, coding standards, reusable components, and internal technical documentation.

Position Requirements:-

• 5+ years of professional experience in backend development.

• Strong hands-on experience with Python and FastAPI.

• Strong experience in RESTful API development and backend services.

• Good working knowledge of ASP.NET Core / .NET Core, C#, Web API, and Entity Framework, with the ability to understand, manage, troubleshoot, and make required changes in existing .NET-based applications and services.

• Strong understanding of Object-Oriented Programming, SOLID principles, design patterns, and clean architecture.

• Hands-on experience with SQL databases such as SQL Server, PostgreSQL, MySQL, or similar.

• Hands-on experience with NoSQL databases such as MongoDB, Redis, DynamoDB, or similar.

• Strong knowledge of SQL queries, database design, indexing, transactions, stored procedures, and query optimization.

• Hands-on experience with Pandas and NumPy for data processing and manipulation.

• Proven experience integrating and working with multiple payment gateways and payment APIs.

• Experience with payment workflows, webhooks, callbacks, refunds, transaction verification, reconciliation, and failure handling.

• Experience integrating third-party APIs and external services.

• Strong understanding of API security, authentication, authorization, JWT/OAuth, and input validation.

• Experience with Git/version control.

• Knowledge of Docker, CI/CD, and cloud platforms such as Azure, AWS, or GCP is preferred.

• Exposure to microservices, caching, message queues, background jobs, or asynchronous processing is a plus.

• Exposure to AI/ML tools, APIs, or concepts is a strong plus.

Key Competencies:-

• Strong backend development and problem-solving skills.

• Ability to build and maintain scalable, secure, and reliable backend systems.

• Strong expertise in Python and FastAPI with practical production experience.

• Ability to work effectively with SQL and NoSQL databases.

• Practical experience with multiple payment gateway integrations and payment workflows.

• Ability to understand and manage existing .NET / ASP.NET Core-based systems.

• Strong debugging and troubleshooting capabilities across application, API, database, and integration layers.

• Ability to identify performance bottlenecks and improve application reliability and response times.

• Strong understanding of clean, maintainable, and testable code.

• Effective collaboration with Frontend, QA, DevOps, and Product teams.

• Ability to take ownership of backend services from development through deployment and production support.