Senior AI Engineer 🇦🇷

About The Mobile-First Company

Most tools for small businesses weren’t built for real operators.
They were built for employees in offices, not people running a business from their phone.

We’re changing that.

We build mobile-first business software that feels like a consumer app, runs on AI, and spreads like a creator brand.

Our first product, Allô, gives you a second number on your phone, answers missed calls with AI, transcribes everything, and syncs it to your CRM.

Over 20,000 businesses use it every day.
Next up: expenses, invoicing, and more.

We’ve raised 5 million euros from Lightspeed, EMBLEM, and 30+ top operators.
Our team is based in Paris, Buenos Aires, and soon Miami.

Drive the evolution of our backend technology, infrastructure, and AI capabilities to ensure high performance, scalability, and seamless integration for our mobile applications.

What will you do:

• Work side by side with our CTO to build the foundations, the present, and the future of our AI capabilities.

• Design and implement systems powered by LLMs that translate directly into user value.

• Integrate these AI services with our current backend infrastructure.

• Instrument, observe, and optimize AI systems with robust evaluation frameworks.

What you’ll be working on

• Implementing and maintaining scalable and reliable AI systems using languages like Python, Kotlin, JS or similar.

• Prompt engineering, vector embeddings and evaluation tools.

• Data modeling and management to optimize the performance and intelligence of our apps.

• Working directly with Cloud services (e.g., AWS, Supabase, Cloudflare).

What we’re looking for

1. Backend AI Engineering:

   • Proficiency in backend development with expertise in languages like Python, Kotlin, JS or similar.

   • Proven delivery of LLM features with LangChain or similar (prompt design, RAG, caching, fine-tuning).

   • Strong system design, performance tuning, and data-modeling skills.

2. Systems Architecture:

   • Expertise in designing scalable and maintainable backend architectures, understanding when to apply different architectural patterns.

   • Ability to instrument, monitor, and troubleshoot AI workloads end-to-end

3. Performance and data

   • You know how to build scalable and maintainable code

   • You care about what to measure and how it impacts business and users

   • You track behavior, usage, and performance, and improve based on it

4. Team player

   • You communicate well and often

   • You collaborate with product, design, and backend

   • You’re not afraid to challenge decisions if it’s for the right reason

   • You’re comfortable working in English

5. Business sense

   • You care about why we build, not just what we build

   • You ask the right questions and help shape the roadmap

   • You prioritize what brings value to users and to the business

6. Culture fit

   • You move fast and don’t wait for permission

   • You give and take feedback without ego

   • You help others, ask for help, and share what you know

   • You want to be part of a small team that wants to win

What matters to us

• You’ve worked in product companies.

• Proven delivery and great understanding of LLM features in production.

• 4+ years of experience designing and building high-performance systems used by millions.

• You’re proactive, autonomous, and know how to fill the gaps.

What we offer

• Competitive salary (in USD or local equivalent)

• Equity package

• Fully remote, with offices in Paris, Buenos Aires, and soon Miami

• 10-day team retreats abroad every quarter

• 30-day onboarding in Paris (we cover flights and housing)

• Laptop and work setup of your choice

• Private health insurance (for US or LATAM hires)

• Option to work from a coworking space if needed

• A tight, ambitious team building something real — fast

We’re not remote-only. We expect you to come to the office a few days a week, or a few weeks every few months. Most of the team rotates.

The official language is English. Most of the team also speaks Spanish and French.

How to apply

Click the Apply button on this page to send your application.

No cover letter needed just tell us who you are and why this role fits you.

Not the perfect match, but want to join us?

Send a spontaneous application to jeremy@themobilefirst.co.

We welcome people from all backgrounds.

If you’re part of an underrepresented group in tech, we especially want to hear from you.