Senior Python Backend Developer — AI Systems, API Integration & Production QA

We are seeking a hands-on Python developer to take ownership of backend engineering, AI-enabled features, system integrations, and release quality for production applications. Python will be the core technology, but the work may also involve Node.js, PHP, MySQL, third-party APIs, and structured software testing.  Develop dependable Python services, APIs, background processes, automation workflows, and AI assisted product features.  Connect with or maintain existing Node.js and PHP components when cross-stack integration is needed.  Create and tune MySQL data structures and queries to support stable application performance.  Apply practical QA and testing standards so features are validated before they reach production. The focus is on maintainable engineering: clear architecture, predictable integrations, meaningful testing, and useful technical documentation rather than short-lived scripts or experimental code. Part A — Core Engineering Responsibilities 1. Python Backend & API Engineering  Develop and enhance Python applications with FastAPI, Django, Flask, or another suitable framework.  Create secure REST endpoints, webhooks, scheduled/background tasks, and external service integrations.  Handle authentication, request validation, exceptions, logging, retry logic, and application observability.  Structure code into reusable, testable modules that are easy to maintain and extend. 2. AI Features & Service Integration  Connect applications with LLM and AI services such as OpenAI, Claude, Gemini, or comparable providers.  Implement AI-driven workflows for automation, data transformation, classification, summarization, or decision support.  Build reliable prompt flows with structured responses, validation, fallback/retry handling, and sensible guardrails.  Integrate AI capabilities with business systems, databases, internal APIs, and operational processes. 3. MySQL Data Layer  Model and maintain MySQL schemas, tables, relationships, indexes, and application queries.  Write efficient SQL and support migrations, backups, consistency checks, and data integrity.  Investigate slow queries, database bottlenecks, and application-to-database issues. 4. Cross-Stack Support: Node.js & PHP  Review, troubleshoot, update, or connect existing Node.js and PHP code when the project requires it.  Create dependable interfaces between Python services and Node.js/PHP applications.  Assist with incremental modernization of legacy modules while keeping active systems stable. 5. Testing & Release Quality  Plan and perform functional, regression, integration, API, and basic performance testing.  Create automated tests for backend services and verify important user or system workflows before release.  Log defects with clear reproduction steps, confirm fixes, and help determine release readiness.  Support a quality-focused workflow through reviews, test coverage, and attention to edge cases. Part B — Development & Delivery Responsibilities  Review project needs and recommend a practical implementation approach before coding begins.  Use Git-based source control with clear branches, commits, and change history.  Assist with deployment, environment setup, production troubleshooting, and urgent fixes when required.  Maintain documentation for APIs, setup, architecture decisions, and key technical workflows.  Provide clear updates on progress, blockers, dependencies, and technical risks throughout the engagement. Deliverables  Production-ready Python source code and required integrations.  AI features and automation workflows implemented and tested.  MySQL database changes, scripts, or migrations where applicable.  Node.js/PHP integration or maintenance work required by the project.  QA test results, bug fixes, and release validation.  Technical documentation and handover notes. Budget & Timeline Budget: $3000 Project length: 1 to 3 months, with potential for ongoing work Required Skills & Expertise Core Development Requirements  Professional Python backend development experience  Hands-on experience building or integrating AI-powered functionality  Working knowledge of Node.js and PHP in mixed-technology environments  Strong MySQL skills, including schema design, querying, and performance troubleshooting  Experience developing REST APIs, webhooks, and third-party integrations  Comfort with Git workflows and debugging live or production systems Quality Engineering Requirements  Experience with functional, regression, integration, and API testing  Ability to identify, document, reproduce, and verify software defects  Automated testing experience for Python/backend services  Strong attention to reliability, failure scenarios, edge cases, and production readiness Preferred / Bonus Experience  FastAPI, Django, or Flask  OpenAI / Claude / Gemini APIs  Docker, CI/CD, AWS, GCP, or Azure  Automation tools such as n8n, Make.com, or Zapier  PostgreSQL, Redis, Celery, or message queues Ideal Freelancer / Developer  At least 3 years of professional software engineering experience, preferably with Python as a primary backend language  A track record of delivering production applications rather than only demos or prototypes  Strong troubleshooting skills across backend code, databases, APIs, and integrations  Able to take ownership of assigned work while keeping the team informed  Writes readable, maintainable code and keeps technical documentation current  Available for regular progress updates, technical reviews, and project discussions Screening Questions Please answer the following in your proposal:  Share 1–2 Python projects you have built for production. What was your role and what did you personally develop?  Describe one AI feature or AI integration you have implemented using Python.  How comfortable are you working with Node.js, PHP, and MySQL alongside a Python codebase?  What is your approach to software quality assurance before releasing a backend feature to production?  Which Python framework do you prefer for API-heavy applications, and why? About the Engagement This role is suitable for a developer who can take ownership of backend development while also supporting AI integration, cross-stack maintenance, database work, and software quality. Strong performance may lead to ongoing development and maintenance work. Please do not send a generic proposal. We will shortlist candidates based on relevant Python experience, AI development examples, cross-stack capability, QA discipline, and clear answers to the screening questions.