Backend Engineer (Python/FastAPI)

AppnGO is a company dedicated to simplifying internal controls and mandatory routines for businesses through a versatile digital platform. Their solution offers ready-made modules covering areas such as health and safety, food safety, alcohol regulations, food waste, data privacy, electrical safety, and fire safety, all tailored to fit daily operational needs. The platform is scalable, supporting everything from single locations to large chains, and features a central dashboard with shared templates to provide comprehensive oversight across departments. Alongside the technology, AppnGO provides expert advisory services to help organizations efficiently comply with legal requirements, combining practical technology with industry expertise.

As a Backend Engineer specializing in Python and FastAPI, you will be responsible for designing, building, and maintaining the backend services that power AppnGO’s compliance and routine management platform. Your role will involve developing RESTful APIs, integrating with both internal and external systems, optimizing database interactions, and ensuring the backend’s scalability, security, and reliability. Collaboration with front-end developers, product managers, and advisors will be key to translating business needs into effective technical solutions. You will also engage in code reviews, write automated tests, contribute to documentation, and support continuous improvement in development processes. This is a full-time, on-site position based in Lahore, offered initially as a six-month contract with the possibility of extension.

Key Responsibilities
- Develop REST endpoints for administrative and client-facing APIs using FastAPI within a layered architecture.
- Design SQLAlchemy models and manage Alembic migrations for a multi-tenant MySQL environment, maintaining a separate database per client.
- Implement and debug background jobs using Celery, Redis, and AWS Lambda/EventBridge.
- Ensure robustness in complex synchronization logic, addressing concurrency challenges and safely applying production data fixes.
- Take ownership of security aspects including authentication, permissions, rate limiting, and input sanitization.
- Write comprehensive tests, review pull requests, and assist with deployment processes.

Required Qualifications
- Minimum of 3 years of backend development experience, primarily using Python.
- Strong proficiency in SQL and relational database modeling, including indexes, transactions, and locking mechanisms.
- Experience working with an Object-Relational Mapper (ORM).
- Production experience with FastAPI or asynchronous Python frameworks.
- Familiarity with Celery or similar task queues, including handling retries and ensuring idempotency.
- A consistent habit of writing automated tests.
- Clear and effective written communication skills in English.

Preferred Qualifications
- Experience working with multi-tenant systems or debugging database deadlocks.
- Knowledge of AWS Lambda and EventBridge services.

This role is based at the company’s office in DHA Phase 4, Lahore. Candidates must reside in Lahore and be able to work on-site daily, as remote or out-of-city applications will not be considered. The position offers the opportunity to work with a modern tech stack including Python 3.12 (async), FastAPI, Pydantic v2, MySQL, SQLAlchemy, Alembic, Celery, Redis, AWS services (Lambda, S3, RDS), pytest, and GitHub Actions.