Senior Python Engineer (FastAPI)

TL;DR

Senior Python Engineer (FastAPI): Build Manychat for Brands from the ground up, shipping backend services for brand campaigns with creators and owning critical infrastructure problems with an accent on scalability, observability, and system design trade-offs. Focus on operating before specs are fully clear, migrating off fragile infrastructure, and ensuring what gets shipped moves the right metrics at real load.

Location: Amsterdam, Netherlands

Company

Manychat builds AI-powered conversational automations for brands and creators across Instagram, Messenger, WhatsApp, and TikTok.

What you will do

• Build Manychat for Brands from scratch: creator invitations, consent handling, and connecting automations and data.
• Ship to real design partners quickly, debugging issues directly in partner channels.
• Own unsolved backend problems: observability from zero, migrating off fragile infrastructure, cutting PHP dependencies, and improving auth and permissions.
• Scale slow data pulls and decide engineering patterns the team will inherit.
• Collaborate with PMs and leadership to shape the product and the code as the product takes shape.
• Operate production infrastructure serving millions of users and validate impact via brand/creator metrics.

Requirements

• 8+ years building backend systems in Python.
• Deep FastAPI experience (or a similar modern framework), including designing services and data models.
• Proven system design experience: defining boundaries, choosing what to build now vs later, and defending trade-offs.
• Experience building for real load and preventing failures at scale.
• Comfort operating without a fully clear spec and shaping the product as it evolves.
• Track record working directly with product and partners, making decisions and measuring whether shipped work moves the metric.

Culture & Benefits

• Hybrid onboarding to start work remotely, with relocation support for you and your family.
• Comprehensive health insurance for you and your family.
• Professional development budget and flexible benefits with a personal budget for health, wellbeing, and home office setup.
• Hybrid work and generous, flexible time off planned with the team.
• Work location flexibility agreed with the team; in-office perks include free meals and snacks.
• Company-funded sport activities, annual offsites, and team-building events; AI tools (Claude, OpenAI, etc.) enabled by default.

Hiring process

• Interviews focused on backend experience, system design, and collaboration with product/partners.
• Evaluation of how you make decisions under ambiguity and measure impact.