Senior Python Engineer (Barcelona-based / Relocation support to Barcelona), Manychat

Barcelona, Spain

Senior Python Engineer, Billing & Accounts

Manychat builds AI-powered automations that help creators and brands engage with their audiences on Instagram, Messenger, WhatsApp and TikTok. We are 400+ people across three continents behind the leading platform for conversational growth.

As a Senior Python Engineer you will create the Python foundation for Manychat's Billing: payments, payment provider integrations, anti-fraud and local regulatory compliance, all tied to the pricing model every feature depends on. There is no roadmap yet, so you will design systems end to end, make the architectural decisions and experiment with what works best. Two mid-level engineers will join after you, and you will help them grow.

What you will do

Design and build Billing's Python foundation, where product features and the existing PHP backend work together.

Build async Python services for payments, payment provider integrations, invoicing, anti-fraud and regulatory compliance.

Design and integrate internal and third-party APIs with clear, stable contracts.

Build for failure: retries, idempotency, consistency and observability, so every payment is handled correctly.

Set the testing, CI/CD and rollout practices this layer runs on.

Mentor and set the technical bar for two mid-level engineers.

Work with cross-functional partners so your technical decisions fit how the business runs.

What we offer

Hybrid onboarding (start remotely) and relocation support for you and your family

Comprehensive health insurance for you and your family

Professional development budget for conferences, courses and learning resources

Flexible benefits package tailored to your priorities

Hybrid work and generous leave options

In-office perks, including free meals and snacks

Company-funded sports activities, annual offsites and team-building events

Manychat is an Equal Opportunity Employer. If you need an accommodation during the interview process, please indicate this in your application.

You need

6+ years of commercial Python development in production, with Python as your primary language and recent hands-on work

Strong expertise in modern Python frameworks (FastAPI preferred; Django or Flask are fine)

Solid experience designing and integrating APIs, including third-party services

Strong understanding of async programming and concurrency (AsyncIO, non-blocking I/O)

Experience with PostgreSQL and large datasets

Experience building and maintaining backend systems under production load

Strong testing practices (unit and integration tests; PyTest preferred), CI/CD pipelines and Docker

Strong engineering judgment: you design systems end to end and make architectural decisions on your own

Mentoring or leadership experience of any kind

Experience working in cross-functional teams, with clear communication

Nice to have

Experience with billing, invoicing or payment systems

Experience with PHP

A product mindset and scale-up experience

Experience with queues, NoSQL or analytical systems

Deep database experience, such as replication, partitioning, sharding or PL/pgSQL

Hands-on experience with AI tools in your engineering work