Role Overview
Efficienza is looking for a mid-senior Python Backend Engineer to design and build secure, scalable backend services for enterprise applications. The core of this role is authentication, authorization, and identity management, alongside building reliable API integrations with communication and notification providers.
You will own backend features end to end: designing APIs, implementing identity and access flows with Keycloak and Amazon Cognito, integrating messaging services such as Twilio, SendPulse, and SMTP, and building the data and caching layers on PostgreSQL and Redis. You will work closely with frontend engineers, DevOps, and product to ship features that are secure by design and stable in production.
This role suits an engineer who has moved past writing isolated scripts and now thinks about service boundaries, security, and integration reliability as first-order concerns.
You will excel if you:
- Write backend code with security, observability, and maintainability in mind from the first commit
- Design API contracts that are predictable, well-documented, and safe for other teams to depend on
- Handle third-party integrations defensively, anticipating timeouts, retries, and failure states
- Treat authentication and authorization as core architecture, not a feature
- Take ownership of features end to end and follow through on production issues
Key Responsibilities
Backend Services and API Development
- Design, build, and maintain RESTful backend services using FastAPI and Flask following consistent conventions
- Define clear API contracts with request validation, structured error handling, and predictable response formats
- Build reusable backend modules and utilities that reduce duplication across services
- Write maintainable, testable code with unit and integration coverage using pytest
- Optimise backend performance: query efficiency, caching strategy, and response latency under load
Authentication, Authorization and Identity
- Implement and maintain authentication flows using Keycloak
- Integrate Amazon Cognito for user pools, identity federation, and token-based authentication where required
- Design and enforce authorization models: role-based and attribute-based access control across services
- Manage JWT issuance, validation, refresh, and revocation securely across the backend
- Implement secure session handling, token storage strategy, and protection against common auth vulnerabilities
- Document identity and access flows clearly so frontend and other services can integrate them correctly
Data, Caching and Storage
- Design and maintain PostgreSQL schemas with appropriate normalisation, indexing, and constraint design
- Write and optimise queries using SQLAlchemy ORM and raw SQL where performance demands it
- Manage database migrations cleanly using Alembic without breaking existing data or dependent services
- Use Redis for caching, session storage, rate limiting, and ephemeral state with appropriate expiry strategies
- Ensure data consistency across the request lifecycle and validate frontend-to-backend data integrity
Reliability, Security and Operations
- Implement structured logging, exception handling, and monitoring across all backend services
- Apply security best practices: input validation, secrets management, least-privilege access, and dependency hygiene
- Troubleshoot production issues with urgency and provide root-cause resolutions, not just patches
- Collaborate with DevOps on CI/CD pipeline integration and deployment automation
- Ensure coding standards, security guidelines, and review practices are consistently followed
Collaboration and Technical Leadership
- Participate in code reviews, technical discussions, and architecture planning with a focus on long-term maintainability
- Work with stakeholders to translate requirements into clear technical designs and API specifications
- Provide technical guidance to junior engineers on backend patterns, security, and integration design
- Contribute to backend documentation: service guides, API references, and integration runbooks
Required Technical Knowledge
| Area | Proficiency | Details |
|---|---|---|
| Python | Core Strength | Backend development, OOP, async patterns, clean modular code |
| FastAPI / Flask | Core Strength | REST API design, validation, middleware, dependency injection |
| Auth & Identity | Core Strength | Keycloak, JWT lifecycle, RBAC and ABAC, secure session handling |
| Amazon Cognito | Proficient | User pools, identity federation, token-based authentication |
| Twilio | Proficient | SMS, voice, notifications, webhook handling, delivery tracking |
| SendPulse / SMTP | Proficient | Transactional and bulk email, delivery status, provider integration |
| PostgreSQL | Proficient | Schema design, query optimisation, indexing, constraints |
| SQLAlchemy / Alembic | Proficient | ORM modelling, raw SQL, migration management |
| Redis | Proficient | Caching, session storage, rate limiting, expiry strategies |
| Git & CI/CD | Experienced | Branching, pull requests, pipeline integration, deployment flow |
| pytest | Proficient | Unit and integration testing, fixtures, mocking external services |
Good to Have
- Experience with AWS services beyond Cognito: S3, Lambda, SQS, Secrets Manager, or CloudWatch
- Familiarity with Docker and containerised local development and deployment
- Exposure to async task processing with Celery, RQ, or similar job queue systems
- Understanding of OAuth 2.0 and OpenID Connect flows beyond basic token handling
- Experience with message queues such as RabbitMQ or Kafka for event-driven architecture
- Awareness of API gateway patterns and service-to-service authentication
- Exposure to LLM API integration and AI-assisted backend automation workflows
Key Deliverables
- Secure, well-documented backend APIs built to agreed standards with test coverage
- Reliable authentication and authorization flows across Keycloak and Cognito, fully documented for integration
- Resilient messaging integrations with Twilio, SendPulse, and SMTP that handle failure states gracefully
- Clean database schemas, migrations, and caching layers that scale with product growth
- Production-stable services with logging, monitoring, and clear runbooks for on-call resolution
What Success Looks Like
- Authentication and authorization flows are secure, well-documented, and rarely the source of production incidents
- Third-party integrations fail gracefully and recover automatically, rather than cascading into outages
- Other engineers can integrate your APIs from documentation alone, without needing to ask how they work
- Production issues in your areas are resolved at the root cause and do not recur in the same form
- Your backend work raises the security and reliability bar for the team rather than adding to its maintenance load
Educational Qualification
- Bachelor's degree in Computer Science, Information Technology, Engineering, or a related field