Founding Python Engineer, Billing & Accounts

About the Position

Founding Python Engineer, Billing & Accounts in Barcelona

Manychat is seeking a Founding Python Engineer to join our team in Barcelona. This role is pivotal in shaping the future of our billing systems as we enter a multiproduct phase.

Responsibilities

• Design and build Billing's first Python layer: the bridge between product features and the existing PHP core.
• Define the patterns for service communication, orchestration, and how responsibility splits between Python and PHP.
• Build scalable, async services for high-load, latency-sensitive billing workflows: payments, invoicing, anti-fraud, and regulatory compliance.
• Own API contracts across systems, keeping them stable, backward-compatible, and clearly bounded.
• Identify functionality worth extracting from the PHP core into Python services where it improves performance or maintainability.
• Design for failure: retries, idempotency, consistency guarantees, and the observability to catch problems early.
• Set the testing strategy, CI/CD, and rollout practices this layer will run on, since you're the one building them from scratch.
• Mentor and set the technical bar for two mid-level engineers who join the team after you.
• Partner closely with Platform and Product to keep architecture grounded in real business needs, not just technical elegance.
• Help shape how Billing supports new products and ventures being built on top of it.

Requirements

• 8+ years of commercial Python development in production environments, including recent hands-on work.
• Strong expertise in modern Python frameworks (FastAPI preferred; Django/Flask fine).
• Real experience designing and integrating APIs, including third-party services.
• Solid understanding of async programming and concurrency (AsyncIO, non-blocking I/O).
• Experience working with PostgreSQL and large datasets.
• Experience building and maintaining high-load backend systems.
• Strong testing practices (unit and integration tests; PyTest preferred).
• Experience with CI/CD pipelines and Docker.
• Strong ownership and product mindset: you connect engineering decisions to business impact and can defend your calls under scrutiny.
• Experience building an environment or foundation comparable to what you'd be building here, ideally under real system constraints rather than a clean slate.

Nice to Have

• Experience working with money: billing, invoicing, or payment systems.
• PHP experience.
• Scale-up company experience.
• Experience with loaded projects and queue systems.
• Infrastructure skills.
• Deep third-party API experience.
• Knowledge of different NoSQL solutions and analytical systems.
• Replication, partitioning, sharding, PL/pgSQL, and other marks of serious database work.

We Offer

• 🌍 Hybrid onboarding to 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 for work-life balance.
• 🍽 In-office perks including free meals and snacks.
• 🤝 Company-funded sports activities, annual offsites, and team-building events.

Manychat is an Equal Opportunity Employer. We’re committed to building a diverse and inclusive team. We do not discriminate against qualified employees or applicants because of race, color, religion, gender identity, sex, sexual preference, sexual identity, pregnancy, national origin, ancestry, citizenship, age, marital status, physical disability, mental disability, medical condition, military status, or any other characteristic protected by local law or ordinance.

This commitment is also reflected through our candidate experience. If you have individual needs that may require an accommodation during the interview process, please indicate this in your application. We will do our best to provide assistance throughout your interview process to ensure you’re set up for success.

About Manychat

• Website: https://manychat.com
• Industry: Marketing
• Headquarters: Palo Alto, CA, USA
• Company Size: 200 - 500
• Founded: 2016