Senior Python Developer (Backend or Data) - Freelance

Context

The company is experiencing strong growth and is scaling its engineering teams to support increasing product usage and infrastructure complexity.

You will join a high-performance environment working on challenging topics such as distributed systems, high-volume data processing, real-time architecture, and system reliability.

Responsibilities

Backend / API

• Design and build robust, scalable APIs (FastAPI or similar frameworks)

• Contribute to architectural decisions (microservices, event-driven systems, decoupled architectures)

• Optimize performance and scalability

Data Engineering (depending on profile)

• Design and maintain data pipelines (ETL/ELT)

• Ensure data quality, reliability, and availability

• Collaborate with Data and Product teams to deliver usable datasets

Engineering & Delivery

• Follow and improve best practices (CI/CD, testing, code reviews)

• Contribute to continuous improvement of the tech stack

• Work closely with Product, Data, and Ops teams

Tech Stack (indicative)

• Python (FastAPI, Django, Flask or equivalent)

• Data: Airflow, dbt, Spark, BigQuery, Snowflake

• Cloud: GCP / AWS

• Databases: PostgreSQL, NoSQL

• Messaging: Kafka / Pub/Sub

• CI/CD: GitHub Actions / GitLab CI

• Containerization: Docker / Kubernetes

Profile

• 7+ years of experience in Python development

• Strong experience with a web framework (FastAPI is a plus)
  OR solid experience in data engineering

Key requirement:

• Previous experience in a scale-up or unicorn environment is strongly preferred

• Comfortable with high-scale systems and performance challenges

• Able to operate in fast-paced, sometimes ambiguous environments with strong autonomy

Soft Skills

• Strong ownership mindset: able to take topics end-to-end

• Ability to structure and clarify complex problems

• Product mindset with business impact awareness

• Strong communication skills in cross-functional teams