Backend Engineer (Freelance)

Location: Remote (UK/EU preferred)

Type: Freelance Contract (Part-time ad-hoc, project-based, potential for long-term collaboration)

Hours: Work on your own schedule but must be available for 1 meeting per week during UK working hours.

About WineFi

WineFi is a data-driven platform for fine wine investing. We combine financial modelling, machine learning, and deep domain expertise to uncover undervalued wines and select assets that outperform the wider wine market. Our work bridges quantitative finance and alternative assets, helping investors make smarter decisions in an opaque market.

The Role

We’re seeking a freelance Backend / API Engineer to design and build production-grade APIs that expose our proprietary wine market data to our platform and external stakeholders.

This role is ideal for someone with experience building clean, reliable, and well-structured APIs on top of complex data systems. Your first project will be to design and build a robust external-facing API layer that serves curated datasets from our internal databases. Over time, you may play a key role in improving how our data systems integrate with our platforms.

Requirements

• Proven experience as a Backend Engineer / API Engineer (3+ years), ideally in a startup or freelance environment.
• Strong Python programming skills (FastAPI, Flask, or similar frameworks)
• Experience building and maintaining production APIs used by external clients
• Strong SQL skills, including query optimisation and schema understanding
• Experience working with PostgreSQL;
• Familiarity with AWS (e.g. EC2, RDS, Lambda, API Gateway, etc.)
• Experience with API security (authentication, rate limiting, key management)
• Strong communicator, able to work independently and asynchronously

Nice-to-have

• Familiarity with ETL pipelines and orchestration tools (Dagster, Airflow, Prefect)
• Experience with Motherduck, DuckDB, Dagster, dbt and Modal also beneficial.
• Exposure to financial, time-series, or alternative asset datasets

Responsibilities

• Design and build scalable, production-grade REST APIs in Python.
• Structure endpoints for both internal platform use and external clients/partners
• Implement authentication, rate limiting, and access control for external users
• Build efficient data access layers on top of PostgreSQL and internal data models
• Optimise query performance and API response times
• Ensure high availability, logging, and monitoring of API services
• Help define best practices for API structure, versioning, and maintainability
• Contribute to the broader architecture connecting data pipelines, databases, and application layers

Collaboration

• Work closely with data scientists and the head of data to align API outputs with models and research.
• Support frontend/platform needs for seamless data consumption.

Why work with us?

• Freelance flexibility with potential for long-term collaboration -- we have lots to build!
• A lean, ambitious environment where your work has direct impact
• The opportunity to build the core API layer of a data-driven investment platform
• Work closely with the founding team across data science and engineering

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