Senior Fullstack Engineer

Job description

Company Overview: Lean Tech is a rapidly expanding organization situated in Medellín, Colombia. We pride ourselves on possessing one of the most influential networks within software development and IT services for the entertainment, financial, and logistics sectors. Our corporate projections offer a multitude of opportunities for professionals to elevate their careers and experience substantial growth. Joining our team means engaging with expansive engineering teams across Latin America and the United States, contributing to cutting-edge developments in multiple industries. Position Title: Senior Fullstack Engineer Location: Colombia and Mexico What you will be doing: The mission of this role is to provi de the customer with flexible, high-caliber, senior product engineering capacity capable of fluidly moving across multiple inherited product codebases as priorities shift. Rather than assignment to a single greenfield project, this software engineer will act as a versatile developer working across frontend, backend, data, and cloud-adjacent application layers to ship meaningful product enhancements, scale workflows, and polish control plane UI elements. The selected candidate must possess the architectural maturity to evaluate diverse brownfield systems, write clean feature logic, implement appropriate testing matrices, and collaborate intelligently with platform engineering and DevOps resources who own the underlying infrastructure. About the platform: The product ecosystem centers around modern TypeScript software engineering, operating in close alignment with AWS cloud services. The active portfolio comprises unique products at different stages of maturity, requiring the engineering team to jump between varying architectural patterns: A highly opinionated, multi-tenant SaaS control plane running Next.js/React on the frontend, NestJS/Node.js on the backend, PostgreSQL/Prisma for data, and centralized AWS platform layers handling tenant lifecycles, global billing, and identity. A security-focused product leveraging a TypeScript-heavy footprint with a React/Vite frontend, NestJS/Node.js backend services, Prisma/PostgreSQL, Lambda functions, and ambient AWS CDK/IaC definitions. Key Responsibilities Build and enhance robust product features across web applications, RESTful APIs, core services, and data-backed workflows. Improve user-facing and admin-facing configurations, updating control-plane surfaces, pricing hooks, or dashboard UIs. Investigate full-stack layers (frontend UI components down to relational database query behaviors) to diagnose system issues and optimize runtime performance. Partner directly with product owners, technical architects, platform engineers, and DevOps colleagues to align application changes with the overarching Launch operating model. Translate complex product specs and technical directives into practical engineering increments supported by clean code and appropriate test coverage. Support integrations with shared core platform capabilities, cloud service layers, background queues, and AI-enabled workflows. Explicitly document implementation workflows, systemic assumptions, and service boundaries to streamline future support handoffs. Required Skills & Experience 5+ years of prior experience working alongside multi-tenant SaaS platforms or a portfolio of dependent products. 5+ years of deep, hands-on production experience building interactive UIs using React. 5+ years of experience designing and implementing scalable APIs, service logic, input validation, and server-side integrations within Node.js environments. Exceptional modern JavaScript and TypeScript development experience. Direct framework experience using Next.js, Vite, or NestJS modules. Practical experience writing relational database patterns, PostgreSQL preferred, defining schemas, managing data migrations, and executing tenant-aware queries. Demonstrated comfort navigating, refactoring, and improving complex existing codebases, rather than just developing software from scratch. Practical engineering discipline applying unit, integration, and component testing methodologies. Nice to Have Skills Familiarity with database interaction modeling using Prisma ORM tools. Hands-on testing automation experience utilizing Playwright, Jest, Vitest, or Testing Library frameworks. Functional familiarity with AWS service architectures (e.g., Cognito identity structures, S3 storage, or serverless Lambda operations). Prior exposure building SaaS platforms, enterprise multi-user products, or configuration dashboards. Conceptual comfort building application features around AI service integrations, document workflows, LLMs, or queue processing (e.g., BullMQ). Cloud literacy to read or lightly adjust deployment metrics or basic IaC configurations (Terraform / AWS CDK). Soft Skills Exceptional diplomatic skills and high emotional intelligence to navigate and manage incumbent-team dynamics respectfully without sacrificing forward progress. Strong cross-functional agility and communication skills to work seamlessly across diverse product, platform, delivery, operations, and support audiences. The cognitive flexibility to move seamlessly between different codebase frameworks and structural conventions without friction. A strong product mindset that goes beyond reading a ticket, showing an innate ability to translate workflow needs into reliable software. The communication agility to collaborate effectively with platform/DevOps infrastructure teams, honoring delivery boundaries while driving feature movement.