Staff Full Stack Engineer, B2B

About the Team

CookUnity B2B is one of the company's fastest-growing divisions, scaling across four verticals — Bulk, Smart Fridge, Healthcare, and Partnership — with a bold H2 2026 north star of $44M in revenue and 120% retention rate.

Our engineering mission is equally ambitious: converge two acquired platforms into a single CookUnity codebase. B2B is the clearest example of that journey in the company — two legacy stacks, two acquired companies, converging into one. It's a high-ownership environment where engineers build at the intersection of logistics, IoT, and consumer software, with computer vision and AI-driven ordering systems already on the near-term roadmap.

If you thrive on hard problems, real business impact, and a small team where your work ships immediately — this is the role for you.

The Role

• Lead the design and implementation of full-stack features across our B2B platform, working directly with product and operations leadership.
• Drive the convergence of multiple legacy stacks into the core CookUnity codebase, making key architectural decisions along the way.
• Automate and simplify operationally complex processes — from smart fridge inventory management to healthcare meal delivery workflows.
• Maintain and scale our AWS infrastructure to support rapid vertical growth.
• Mentor engineers across the team and contribute to raising the technical bar.
• Be hands-on and build products used by thousands of corporate customers from day one.

Our Current Stack:

Languages: Java, JavaScript, TypeScript

Frameworks: ReactJS, NestJS

Infrastructure: AWS, Kubernetes, MySQL

Methodology: Agile / Service-Oriented Architecture

Responsibilities

• Ensure the platform is scalable, reliable, and efficient across all B2B verticals.
• Identify and address technical debt and performance bottlenecks proactively.
• Own the design and implementation of platform features within our JavaScript/Java stack that engage customers and drive meaningful business outcomes.
• Iterate on new and existing features to improve user experience, performance, and reliability.
• Actively drive the adoption of strong software architecture, engineering best practices, and emerging technologies.
• Lead and participate in code reviews; mentor engineers across experience levels.
• Contribute technically by being a hands-on coder, removing roadblocks, and resolving technical issues end-to-end.
• Partner with Product, Operations, CX, and other teams to continuously refine and improve our platform in an agile environment.
• Support the on-call rotation to help the business run 24/7
• Contribute to documentation, deployment processes, and continuous improvement initiatives.

AI Usage & Engineering Excellence

At CookUnity B2B, AI is not a buzzword — it's part of how we build. We expect our engineers to actively integrate AI tools into their daily workflow to move faster and build better.

Expected (day-to-day):

• Use AI-powered coding tools (GitHub Copilot, Claude / Codex) to accelerate development, code reviews, and debugging.
• Apply AI to automate repetitive engineering tasks — test generation, boilerplate, documentation, and internal tooling.
• Leverage AI assistants to explore architectural trade-offs, prototype quickly, and improve code quality.
• Stay current on AI tooling best practices and share learnings with the team.

Nice to have (leadership signal):

• Experience building AI-powered product features (e.g., smart recommendations, automated ordering, anomaly detection).
• Ability to evaluate and introduce new AI tools or frameworks to the team, establishing best practices and adoption playbooks.
• Prior work integrating LLM-based workflows, automation pipelines, or agentic tooling into production systems.

Minimum Requirements

• Proven experience designing and building cloud-native architectures: backend services, APIs, and full-stack web applications.
• Strong proficiency with NodeJS / NestJS, ReactJS, AWS, and MySQL (or equivalent relational databases).
• Experience with Java in a production environment.
• Solid understanding of distributed systems, service-oriented architecture, and API design.
• Experience with automated testing and CI/CD pipelines.
• Advanced English proficiency (written and spoken) — we're a distributed, international team.

Preferred Requirements

• Previous experience leading or mentoring engineers in a fast-moving product team.
• Excited by the opportunity to grow into a broader technical leadership role as the division scales.
• Experience with agile development methodologies and tools such as Jira.
• Strong communication and collaboration skills — able to work effectively across product, design, and operations.
• Comfortable working in a startup environment where priorities shift and ownership is broad.
• Experience with observability tools (e.g., Datadog), infrastructure-as-code, or platform migrations.
• Familiarity with IoT, hardware integrations, or computer vision systems is a strong plus given our Smart Fridge roadmap.

Benefits:

💸 Get paid in USD.

🗺 Work remotely: design the life that you want.

⛱ Enjoy 15 days of vacation each year from the start date.

🎄 16 fully paid Argentinean holidays.

🩺 Healthcare Benefit: Monthly stipend to use in your preferred healthcare provider.

🗓️ 5- year Sabbatical: After 5 years with CookUnity, you get a 4-week paid sabbatical.

🐣 Paid family leave.

🕯 Compassionate Leave: 3-5 days each time the need arises.

🧘🏽‍♀️ Flexible benefits, your way: a prepaid card you can use on wellness, learning, food, and more.

🤖 AI-forward workplace: enterprise access to ChatGPT and Claude to help you work smarter and grow faster.

🧑‍🏫 Personalized English coach.