Senior Backend Dev (Go / Python) - Freelance

Context

Fast-growing international marketplace scale-up undergoing a major backend modernization phase.

The technical environment is progressively evolving from a historical monolith toward a distributed, service-oriented architecture, with strong challenges around scalability, security, reliability, and engineering ownership.

The mission is part of a Platform team responsible for building and maintaining core technical foundations, including authentication, authorization, and data security layers.

Technical Challenges

• Progressive migration toward a distributed architecture

• Designing loosely coupled, high-cohesion services

• Full service ownership (build & run model)

• Raising engineering standards across teams

• Securing user flows and data access at scale

Tech Stack

Backend

• Golang

• Python (Django, FastAPI, SQLAlchemy, Celery)

Data

• PostgreSQL

• Redis

• Kafka

• RabbitMQ

• BigQuery

Infrastructure

• GCP

• Kubernetes (GKE)

• Docker

• ArgoCD

• CircleCI

• GitHub

• Datadog

Responsibilities

• Design, build, and maintain scalable backend services

• Contribute to the transition toward a service-oriented architecture

• Develop secure and high-performance APIs

• Ensure monitoring, reliability, and production readiness

• Work in a “you build it, you run it” environment

• Collaborate with Product, Data, and Engineering teams

• Maintain high-quality documentation and code standards

Profile Required

Technical Expertise

• Strong backend development experience

• Proficiency in Golang and/or Python

• Solid understanding of distributed systems and microservices

• Experience designing and integrating APIs

• Ability to onboard quickly onto an existing codebase

• Strong engineering discipline (testing, documentation, clean code)

Rigor & Autonomy

• End-to-end ownership mindset

• Strong organizational skills

• Pragmatic and impact-focused

• Proactive communication when facing blockers

Communication

• Strong ability to summarize technical topics clearly

• Comfortable in an international environment

• Fluent English (written and spoken)

Bonus

• Experience with authentication & authorization concepts (OAuth2, OIDC, access control, user & permission management)