Senior Full Stack Engineer (Cx Platform) (Paraná, Argentina)

Felix; Paraná; Hybrid; BRL 180,000 - 320,000; Full time

Benefits offered by this job

Stock options

Annual bonus

Health plan (medical, dental, vision)

Unlimited PTO

Parental leave

Remote work now, Hybrid later

Learning opportunities

Job summary

Félix is seeking a seasoned software engineer to own end-to-end features on our CX platform. You will build modules from React UI to Node.js services and data models, with emphasis on secure integration and operational efficiency.

We value strong engineering fundamentals over tool specifics. The role offers a remote-first model with a future transition to hybrid work, and opportunities to impact AI-powered fintech services for cross-border finance.

Qualifications

• 5+ years of experience as a Software Engineer in a fast-paced environment.
• Fluent or advanced English.
• Advanced React & UI Engineering: deep understanding of React, HTML/DOM, CSS, HTTP; TypeScript proficiency expected.
• Solid Node.js / Backend Skills: REST APIs, service boundaries, error handling, clean backend patterns.
• Data Modeling: relational schemas, performant queries, transactional integrity.
• Security & Authorization: RBAC over sensitive data.
• Aggregation / BFF Patterns: backend-for-frontend or aggregation layers across microservices.
• Problem Solving: strong analytical and hands-on engineering skills.

Responsibilities

• End-to-End Feature Ownership: build modules from UI to data models.
• Module Development: design and ship CX platform modules and workflows.
• Secure Integration Layer: implement BFFs/aggregators with strict authorization.
• Operational Efficiency: translate workflows into solutions reducing handling times.
• Engineering Craft: maintain high-quality patterns and mentor peers.

Skills

5+ years exp

Fluent English

Advanced React UI

Node.js backend

Data modeling

RBAC security

RBFF/Aggregation patterns

Problem solving

Tools

PostgreSQL

Job description

Parana

3 days ago

Hybrid

Full-time

About Us

At Félix , we are building the indispensable financial companion for Latinos in the US. We combine an AI-powered, conversational-first interface with real-time financial infrastructure to make cross-border money movement as easy as sending a text. Starting with fast, affordable remittances powered by AI and crypto rails, we are expanding into credit, savings, and wallet services to support the complete immigrant financial journey. Our ambition is to deliver a white-glove financial experience with the simplicity of a conversation to a community the traditional financial system has historically overlooked.

We are a hyper-growth Series C company, backed by over $300 million in funding from top-tier global investors, including Andreessen Horowitz, QED, Castle Island, Switch Ventures, HTwenty, Monashees, General Catalyst Customer Value Fund. This isn't just about the numbers; it's a testament to the trust our investors have in our vision and our team. Additionally, Félix was selected as an “Endeavour Entrepreneur” and was a recipient of the CrossTech Fintech Startups Award.

Joining Félix means you will be part of a team building a legacy, a company that will outlive us all. This is a rare opportunity to apply your skills to a deeply meaningful mission—serving a community that has been underserved for too long because we are obsessed with our customers. We get things done with urgency and focus, driven by extreme ownership over our impact. We collaborate without ego, fostering radical transparency and fierce loyalty so we can grow together. Because we aim for insanely great rather than just good enough, we stay insatiably curious—always experimenting, building the future today, and delivering a product that truly makes our users' lives better.

About the Role

We are transitioning our core operational capabilities from third-party low-code solutions to a robust, highly scalable, in-house ecosystem. As part of the CX Platform team, you will own the construction of the operational modules that power our daily business, building features end-to-end from the React UI down to the Node.js services that aggregate and protect our data.

You will own the modules, screens, and APIs that the CX team relies on every day, designing, building, and shipping them end-to-end. Your work has a direct, measurable impact: every feature you ship reduces handling times, removes friction, and gives our operators superpowers.

If you love taking features from idea to production without artificial silos between frontend and backend, and you get satisfaction from shipping tools that real humans rely on to do real work, this is your place.

We care more about strong engineering fundamentals than expertise in any specific tool. If your foundations are solid, picking up adjacent technologies should be second nature. That said, here is the stack you will be working with day to day:

• Front-end: Advanced React, TypeScript, Component-Driven UI, Modular CSS Architectures.
• Data Layer: Relational data modeling (PostgreSQL or similar), schema design, query optimization, transactional integrity.
• Security & Access: RBAC, secure handling of sensitive data, strict environment isolation.
• Tooling & Delivery: Modern build tools and bundlers, Git workflows, CI/CD pipelines.

Responsibilities

• End-to-End Feature Ownership: Build complete operational modules, from the React UI down to the Node.js services and data models that power them. You own the feature, not just a layer of it.
• Module Development: Design and ship the modules that live on top of our CX platform: high-density data views, complex operational workflows, and internal tools that drastically reduce cognitive load for our operators.
• Secure Integration Layer: Implement intermediary layers (BFFs, aggregators) that consume internal microservices and external providers, standardize payloads, and enforce strict authorization rules before data reaches the client.
• Operational Efficiency: Collaborate shoulder-to-shoulder with core business stakeholders to deeply understand their daily workflows, then translate that understanding into technical solutions that materially reduce handling times.
• Engineering Craft: Champion clean patterns, pragmatic design, and a high quality bar across the modules you ship. Mentor peers and elevate the broader engineering culture.

Requirements

• 5+ years of experience as a Software Engineer in a fast-paced, dynamic environment.
• Fluent or advanced English.
• Advanced React & UI Engineering: Deep understanding of React and solid foundations in web standards (HTML/DOM, CSS, HTTP). TypeScript proficiency is expected.
• Solid Node.js / Backend Skills: Proven ability to design and build well-structured REST APIs in Node.js. Strong grasp of API design, service boundaries, error handling, and clean backend patterns.
• Data Modeling: Comfortable designing relational schemas, writing performant queries, and reasoning about transactional integrity.
• Security & Authorization: Hands-on experience implementing authentication and authorization flows, especially Role-Based Access Control (RBAC) over sensitive data.
• Aggregation / BFF Patterns: Ability to design backend-for-frontend or aggregation layers that consume multiple microservices and expose a clean, secure surface to the client.
• Problem Solving: Excellent problem-solving skills with a balance of creative UI implementation and strict engineering rigor on the backend.

Nice to have (highly desirable):

• Technical Leadership: Track record of mentoring engineers, raising the bar in code reviews, and influencing architectural decisions beyond your immediate scope.
• Internal Tools / Enterprise Ops: Experience building internal tools, CRM systems, or high-density data applications focused on operational efficiency and scale.
• Regulated Environments: Background in highly regulated sectors (Fintech, Healthcare) dealing with strict role-based access control (RBAC) and data isolation.

What We Offer

• Initial stock options grant
• Annual performance bonus
• Health, dental, and vision plans
• Work model: currently fully remote, with a future transition to a hybrid setup.
• Continuous learning opportunities
• Continuous learning opportunities
• Unlimited PTO
• Paid parental leave
• Empowering opportunities for growth in a dynamic entrepreneurial environment

Equal Opportunity Employer

At Félix, we are committed to providing equal employment opportunities to all qualified employees and applicants without regard to race, religion, nationality, sex, sexual orientation, gender identity, age, or disability. This policy applies to all terms and conditions of employment, including recruitment, hiring, placement, promotion, training, compensation, benefits, and termination.

Want to learn more about our privacy practices? Check out our Privacy Policy .

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I build and structure full frontend applications (components, state, architecture)

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Defining the overall architecture and how the system is structured before and as it's built

Designing specific services or modules and how they connect within the broader system

Implementing well-defined features and services, focusing on quality and delivery

Improving and maintaining existing systems: fixing, optimizing and scaling what's already there

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