Senior Python Backend Developer (Platform) We're looking for a Senior Python Backend Developer to join the Platform team and take ownership of core backend systems powering Aghanim — a direct-to-consumer (DTC) platform that helps mobile game developers monetize outside app stores. We act as a Merchant of Record, handling payments, compliance, and taxation across 200+ territories, while providing game studios with tools for LiveOps automation, player segmentation, and community engagement.The platform serves 100+ live games through customizable Game Hubs (DTC web stores), in-game offers, subscriptions, and virtual currency systems — all with real-money transactions requiring high reliability and fraud protection.The codebase follows domain-driven design with 60+ business domains, strict code quality standards, and AI-assisted development as a standard part of the workflow. You'll work across a modern Python stack — FastAPI, SQLAlchemy v2, PostgreSQL, Redis — with a heavy integration layer connecting game backends, payment providers, and external services.Role ResponsibilitiesBackend Architecture and System DesignDesign and implement backend systems and business domains end-to-endDefine domain boundaries, data models, and API contractsMake architectural decisions aligned with scalability, reliability, and maintainabilityContribute to long-term evolution of system architecture and technical standardsBackend DevelopmentDevelop backend services using Python with a focus on clean, maintainable, and testable codeBuild APIs, background workers, and event-driven components with clear layered architectureImplement integrations with external services, including payment providers and game backendsHandle complex workflows related to transactions, state management, and system interactionsData and InfrastructureDesign and optimize database schemas and queries in PostgreSQLImplement caching, rate limiting, and distributed coordination using RedisEnsure efficient handling of high-load scenarios and large-scale data processingReliability and TestingDefine and implement testing strategies, including unit, integration, and functional testsEnsure high reliability of production systems, especially in payment-related flowsDebug and resolve complex production issues with a focus on root cause analysisContribute to observability through logging, metrics, and monitoringCross-functional Collaboration and LeadershipCollaborate with engineering and product teams on feature design and deliveryConduct code reviews and mentor other developersDrive engineering best practices and maintain high code quality standardsContribute to technical decision-making and team-level architecture discussionsRequired QualificationsPython 5+ years of commercial experience.Strong experience with FastAPI or similar async frameworks (Starlette, aiohttp).Deep knowledge of SQLAlchemy (preferably v2) — ORM internals, relationships, performance tuning, migrations (Alembic).PostgreSQL — advanced query optimization, indexing strategies, schema design, partitioning.Redis — caching strategies, rate limiting, distributed locks, pub/sub patterns.Proven experience designing and building REST APIs with clear layered architecture.Pydantic — data validation, serialization, complex schema design.Strong understanding of async/await patterns, concurrency, and event loops in Python.Experience integrating with third-party APIs and building reliable webhook/callback systems.Experience designing systems and making architectural decisions — choosing patterns, defining domain boundaries, managing technical debt.Solid testing culture: pytest, async tests, fixtures, factories, coverage strategy.Experience mentoring developers and conducting meaningful code reviews.Git, CI/CD, trunk-based or feature-branch workflows.AI: confident use of AI tools in daily development — from code generation and refactoring to debugging, test writing, and code review; with an understanding of risks (hallucinations, security, licensing) and mandatory result validation.Preferred QualificationsExperience with Google Cloud services (BigQuery, Firestore, Pub/Sub, BigTable, Cloud Storage).Experience with background job processing (ARQ, Celery, or similar).Experience with webhook delivery systems, retry strategies, and idempotency.Experience with Datadog, Sentry, or similar observability tools.Experience in gaming, e-commerce, or fintech domains.Experience building multi-tenant SaaS platforms.Experience with event-driven architecture and message queues.Experience with high-load systems and horizontal scaling.What Success Looks LikeNew features and domains are delivered end-to-end with clean architecture, solid test coverage, and no reliability regressions.Integrations with game backends and external services work reliably under production load.Codebase quality stays high — your code reviews and mentoring raise the bar for the team.Production incidents in your areas are rare, and when they happen, they're resolved quickly with permanent fixes.You're a go-to person for architectural decisions and technical design within the team.Why Join UsModern Python stack (3.13, FastAPI, SQLAlchemy v2) with real architectural ownership.Small team (15–20 engineers) with high autonomy and fast decision-making.Strict engineering culture: enforced code standards, comprehensive test guidelines, AI-assisted development.Direct impact on a platform serving 100+ live games with real-money transactions across 200+ territories.Mission-driven company helping game developers achieve financial independence from app stores.Opportunity to shape backend architecture, engineering practices, and team standards in a fast-growing startup.Aghanim helps game developers achieve financial and creative independence by providing the solutions they need to launch, run, and grow their businesses.