The Mobile-First Company - Sr. Backend Engineer (Java/Kotlin)

Location: Buenos Aires, Argentina (Hybrid)

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 dolars from Lightspeed, EMBLEM, and 30+ top operators. Our team is based in Paris, Buenos Aires, 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 backend, and AI systems.

• Develop and enhance backend systems for both existing and new applications in conjunction with mobile engineers.

• Contribute to systems design, infrastructure planning, CI/CD processes, and data workflows.

What you'll be working on:

• Implementing and maintaining scalable and reliable backend systems using languages like Kotlin, Java, Go, Python or similar.

• Designing and defining backend tools, databases, and the architecture of our apps.

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

• Creating tools, libraries, or components to enhance the efficiency of backend development processes.

What we’re looking for

• Backend Engineering:

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

• Familiarity with database design, management, and optimization.

• Track record of building and maintaining scalable and reliable backend systems.

• Experience with AI is a strong plus, especially in applying models to real-world product use cases and optimizing performance in production environments.

• Systems Architecture:

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

• Capable of monitoring the whole architecture using tools like New Relic or Datadog.

• 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

• How you think

• You care about why we build things, not just how.

• You ask smart questions, challenge ideas when needed, and help shape what’s next.

• You think in terms of user value and business impact.

• How you work

• You communicate clearly, give feedback with no ego, and help others grow.

• You move fast, take ownership, and thrive in ambiguity.

• You're comfortable working in English — and in a small team with big goals.

What matters to us

• You’ve worked in product companies

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

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

• You can communicate in English, since that's our official language. Most of the team also speaks Spanish and French.

What we offer

• Competitive salary (in USD or local equivalent)

• Equity package

• 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)

• A tight, ambitious team building something real — fast

The Interview Process:

• Silver.dev Recruiter Screening

• Client People Interview

• Client Technical Interview

• Client Behavioral Interview