Backend Developer (Fast API+ AWS)

r3 Consultant; Maharashtra; Hybrid; INR 800,000 - 1,500,000; Full time

Job summary

r3 Consultant is looking for a highly skilled Backend Developer with expertise in FastAPI and AWS infrastructure. The ideal candidate should have 4-8 years of experience in backend development and be comfortable building production-grade APIs and handling cloud-native deployments.

This role involves developing scalable AI-driven web and mobile platforms, integrating various systems such as payments and authentication. Strong experience with databases, real-time systems, and monitoring tools is essential.

Qualifications

• 4-8 years of experience in backend development.
• Strong experience with FastAPI and AWS infrastructure.
• Deep knowledge of DynamoDB and database optimization.

Responsibilities

• Develop and maintain scalable backend APIs using FastAPI.
• Design secure and efficient backend architecture.
• Manage AWS infrastructure and deployment pipelines.

Skills

Backend Development

WebSockets

Microservices

AWS & Cloud Infrastructure

Database Experience

Authentication & Security

Payments & Subscription Systems

Monitoring & Reliability

Additional Preferred Skills

Job description

Job Title

Backend Developer (FAST API + AWS)

Location

Pune (Hybrid)

Work Experience

4-8 years

Job Summary

We are looking for a highly skilled Backend Engineer with strong experience in FastAPI, AWS infrastructure, authentication systems, payment integrations, monitoring systems, sockets, and scalable backend architecture. The candidate should be comfortable building production-grade APIs, working with real-time systems, and handling cloud-native deployments.

This role involves working on scalable AI-driven web and mobile platforms with integrations across payments, subscriptions, authentication, analytics, monitoring, and real-time communication systems.

Required Skills

• Backend Development – Strong experience with Python and FastAPI; designing scalable REST APIs and async backend systems; deep understanding of backend architecture, middleware, dependency injection, and background task handling.
• WebSockets – Strong experience with WebSockets, socket lifecycle management, reconnection handling, and real-time communication systems; experience handling concurrent socket connections and event-driven systems.
• Microservices – Knowledge of microservice-oriented architecture.
• AWS & Cloud Infrastructure – Hands‑on experience with EC2, S3, DynamoDB, Load Balancers; production deployments, scaling, monitoring, security hardening; CI/CD and deployment automation.
• Database Experience – Deep knowledge of DynamoDB, including GSIs, query optimization, partition key design, scaling considerations, single-table design; experience with MongoDB/PostgreSQL.
• Authentication & Security – Experience with Auth0 or similar; JWT, session handling, OAuth flows, RBAC/permission systems, secure API design, backend authorization flows.
• Payments & Subscription Systems – Experience integrating Stripe APIs; subscription lifecycle management, webhooks, payment intents, billing flows, invoice handling; revenue integration for mobile subscriptions.
• Monitoring & Reliability – Experience with monitoring tools such as CloudWatch, Datadog, Grafana, Prometheus, Sentry; alerting systems and production debugging workflows.
• Additional Preferred Skills – Support Flutter or React applications; mobile backend requirements; production system debugging and performance improvement.

Responsibilities

• Develop and maintain scalable backend APIs using FastAPI.
• Design secure and efficient backend architecture.
• Manage AWS infrastructure and deployment pipelines.
• Build real‑time communication systems using WebSockets/sockets.
• Build payment and subscription systems using Stripe and RevenueCat.
• Optimize DynamoDB schemas and GSI usage for performance.
• Implement authentication and authorization systems.
• Monitor infrastructure, backend services, socket systems, and production environments.
• Improve system reliability, performance, and scalability.
• Collaborate with frontend, mobile, and DevOps teams.
• Participate in debugging, testing, and production monitoring.

Ideal Candidate

• Strong problem‑solving ability.
• Comfortable working in fast‑paced startup environments.
• Able to independently design and implement backend systems.
• Good understanding of scalability and production engineering.
• Strong ownership mindset and debugging skills.