Full-stack Engineer and Systems Architect

🇧🇷 🇦🇷 🇨🇴 🇲🇽 🇵🇾 🇨🇱 🇨🇷 🇵🇪 🇺🇾 Exclusive to candidates based in Brazil, Argentina, Colombia, Mexico, Paraguay, Chile, Costa Rica, Peru, and Uruguay

Requirements

Must-haves

• 8+ years of software development experience
• Proficiency with TypeScript
• Proficiency with Python
• Experience directing AI coding agents with rigorous review and verification practices
• Experience building component-driven front-ends and data-heavy internal consoles
• Experience with Postgres, including migrations, indexing, and query performance diagnosis
• Experience with containers and production deployments
• Experience with monorepos and multi-repos (e.g., workspaces, shared packages, versioned internal contracts)
• Experience building CI/CD pipelines (e.g., merge gates, reproducible builds, release and rollback, environment parity)
• Experience owning system architecture decisions in production
• Experience implementing protocols against specifications and building the conformance tests
• Experience with messaging APIs (e.g., carrier, WhatsApp, chat)
• Experience in instrumenting systems and reading traces for observability
• Ability to become productive with unfamiliar frameworks within a day
• Ability to hand-code and deeply review AI-generated code
• Deep understanding of typed schemas as a single source of truth, generated clients, and centralized validation
• Deep understanding of UX quality for pixel-perfect feature execution
• Interest in cutting-edge technologies and proposing new ideas for internal tools
• Strong communication skills in both spoken and written English

What makes you stand out

• Senior-level experience backed by strong, independent judgment
• Ability to troubleshoot hands-on without relying on AI coding tools

Nice-to-haves

• Startup experience
• Experience with business messaging platforms in production (e.g., Apple Messages for Business, RCS Business Messaging, WhatsApp Cloud API)
• Experience with Rust, Swift
• Experience with iOS or Android device automation, or computer vision applied to testing
• Experience designing certification, audit, or compliance systems
• Bachelor’s Degree in Computer Engineering, Computer Science, or equivalent

What you will work on

• This is an architecture role that writes code, not a coding role that occasionally diagrams.
• The hard problems here are not framework problems. There are questions like:
• What is the right abstraction for behavior that must stay identical across brands with wildly different experiences?
• Where does a system have to be deterministic and reproducible, and where can human judgment live?
• What belongs in a shared contract versus a local implementation?
• How do you make a system's invariants checkable rather than aspirational?
• We need someone who thinks in systems and concepts first, and who can then build the thing. Specifically:

System architecture and concept design

• Define service boundaries, data models, and contracts between components
• Design seams that let the same code run locally and hosted without a rewrite
• Turn fuzzy capabilities into clear models of core entities and rules
• Apply MIT concept design methodologies to agentic system design
• Design abstractions that keep behavior consistent across brands with very different experiences
• Decide where systems must be deterministic and where human judgment can apply
• Make architecture decisions alongside founders with product and engineering backgrounds

Verification and documentation

• Plan up front how each system will prove its correctness, rather than retrofitting tests
• Make system invariants checkable through code and tests
• Write specifications, decision records, and product invariants in RFC 2119 language

Agent-driven development

• Direct AI agents to build features and review their output in depth before merging
• Write specs that agents can execute and reviewers can check
• Maintain agent instructions and skills as first-class artifacts
• Run independent adversarial reviews before opening pull requests
• Catch plausible but wrong results (e.g. silent safety gates, empty version pins, hollow dependency directories)