Senior Backend Engineer - Python Microservices for FinTech

About the Role

We're looking for a Senior Backend Engineer remote to join our innovative team at DealSize.ai. In this role, you will own and evolve our Python microservices architecture, designing scalable systems that directly impact our users. This is a unique opportunity to make critical technical decisions while working fully remotely, with a team that values autonomy and collaboration.

What You'll Do

• Design & Build Microservices: Architect and implement FastAPI services handling financial data ingestion, user strategies, and trading integrations.
• Own Database Architecture: Design PostgreSQL schemas, optimize queries, manage migrations with Alembic, and implement vector search with pgvector.
• Scale Infrastructure: Deploy and manage services on AWS ECS, implement serverless patterns (Lambda, API Gateway), and optimize for cost/performance.
• Build Data Pipelines: Integrate third-party financial data providers, implement caching strategies with Redis, and ensure data consistency across services.
• Drive Technical Excellence: Establish patterns for error handling, observability, testing, and code quality across the backend.

Requirements

• 5+ years of experience in Python, particularly with async patterns (asyncio, FastAPI/Starlette).
• Strong system design skills – ability to whiteboard a scalable architecture and explain trade-offs.
• Deep PostgreSQL expertise – schema design, query optimization, indexing strategies, migrations.
• Experience with AWS services – ECS, Lambda, RDS/Aurora, ElastiCache, S3, Serverless, etc.
• Mastery of API design – RESTful patterns, versioning, authentication, rate limiting.
• Production mindset – monitoring, logging, error handling, graceful degradation.

Nice to Have

• Experience with vector/graph databases and embeddings for semantic search.
• Familiarity with Terraform for Infrastructure as Code (IaC).
• Background in trading/financial domain.
• Knowledge of message queues (SQS, Redis Streams, Kafka).

What We Offer

• Remote Work: 100% remote work with flexible hours.
• Competitive Salary: Industry-competitive salaries ranging from €60K to €80K.
• Equity: Equity package included.
• Holidays: 24 days holiday plus local public holidays.
• High impact: Your work directly shapes the product and architecture.
• Ownership: Lead technical decisions, not just implement tickets.
• Growth: Learn AI/ML integrations, financial systems, and scale challenges.
• Speed: Ship weekly, iterate fast, see your code in production immediately.