Open to hearing about interesting opportunities

I build fast, accessible interfaces for products used by millions.

Lead Frontend Engineer with 12+ years shipping web and mobile products — from banking apps at Happen Bank (formerly LendingClub) and Sicredi to enterprise platforms at SAP. I care about performance, design systems, and the details that make software feel effortless.

View selected work Get in touch
12+
Years shipping products
1M+
Users served in production
9
Companies & clients
20+
Apps & platforms delivered

What I do

Engineering that shows up in the product

I focus where frontend work is most visible to users and most valuable to the business — speed, systems, and reliability across platforms.

  • Performance & Core Web Vitals

    Profiling, code-splitting and rendering strategy to keep interfaces fast under real-world load and constraints.

  • Design systems & UI architecture

    Reusable, accessible component libraries that scale across teams and keep products visually consistent.

  • Cross-platform apps

    Web, React Native and Flutter — one product language across every screen your users reach.

  • Full-stack integration

    Wiring frontends to Node.js, Django and Java services with clean contracts and resilient data flow.

Selected work

Products I've helped build

A few projects that span fintech, editorial and commerce — from apps serving millions to focused side projects.

Happen Bank (formerly LendingClub)
Fintech · Web & Mobile2021 — Present

Happen Bank (formerly LendingClub)

Led frontend for a banking product serving millions of users. Shipped new features, drove page-speed and accessibility gains, and integrated with Django, Node.js and Java services.

  • React
  • TypeScript
  • Performance
  • A11y
Audible Blog
Editorial · Next.js2021

Audible Blog

Built the Audible (Amazon) blog with Next.js, improving SEO and engagement through server rendering and a reusable, scalable component system.

  • Next.js
  • SSR
  • SEO
Sicredi Mobi
Mobile Banking2017 — 2018

Sicredi Mobi

Improved UX and security for a hybrid mobile banking app, optimizing assets and API requests to cut load times.

  • Hybrid
  • Kony
  • Security
Porto Pão App
Commerce · IonicSide project

Porto Pão App

Customer ordering app integrated directly with a legacy ERP's SQL database. Built end-to-end with Ionic, Node.js and MongoDB.

  • Ionic
  • Node.js
  • MongoDB
yt-assist
Side project · GenAIPersonal

yt-assist

Web app and browser extension that summarizes any YouTube video with generative AI — paste a link and get the key insights in seconds, no fluff.

  • GenAI
  • Browser Extension
  • TypeScript
PostCraft
Side project · SaaSPersonal

PostCraft

AI content studio for Instagram: generates on-brand captions, images and hashtags ready to publish — no design skills needed. Built with Next.js, OpenAI and Stripe.

  • Next.js
  • GenAI
  • Stripe
Arbitrader
Side project · FintechPersonal

Arbitrader

Node.js bot that scans crypto exchanges for price gaps and executes cross-exchange arbitrage opportunities automatically.

  • Node.js
  • Crypto
  • Automation

Career

A decade-plus building for the web

From internships in enterprise backends to leading frontend at banks and global platforms.

Experience

  1. 2021 - present

    Lead Frontend Engineer

    Happen Bank (formerly LendingClub)

    Led the development of the Happen Bank (formerly LendingClub) banking app, serving millions of users with a seamless financial experience. Built new features and optimized performance for the company's website, improving page load speed and accessibility. Integrated the frontend with several backend services (Django, Node.js, Java), ensuring smooth communication across systems. Led a team of developers, providing guidance on best practices, code reviews, and system architecture decisions.

  2. 2021 - 2021

    Lead Frontend Engineer

    HappyFunCorp

    Developed the Audible Blog (Amazon subsidiary) using Next.js, improving SEO and user engagement. Led the development of Kithward Backoffice, collaborating with stakeholders to define project scope, prioritize features, and deliver results on schedule. Designed and implemented reusable UI components, ensuring a consistent and scalable design system.

  3. 2020 - 2021

    Lead Frontend Engineer

    ilegra

    Developed the Thomson Reuters Brazilian Accounting Platform using Angular, streamlining financial data management for enterprises. Led the development of React Native apps for security systems, integrating IoT features for home monitoring and alert systems. Implemented automated testing with Jest, increasing test coverage and reducing regression issues.

  4. 2018 - 2020

    Lead Frontend Engineer

    SAP

    Architected and led the development of frontend solutions for enterprise applications, focusing on performance and scalability. Built PoC solutions utilizing Machine Learning and Big Data to enhance decision-making capabilities. Designed and developed user-friendly interfaces for internal tools using React and Flutter. Managed SCRUM processes, optimizing team efficiency and delivery schedules.

  5. 2017 - 2018

    Senior Software Engineer

    Sicredi

    Developed and maintained Sicredi Mobi, a hybrid mobile banking app, improving user experience and security. Enhanced app performance and reduced load times by optimizing mobile assets and API requests.

  6. 2016 - 2017

    Mobile Developer

    Qintess (formerly Resource IT)

    Built mobile banking applications using Kony Framework, enhancing security and usability. Provided ongoing support and feature updates, improving app stability and performance.

  7. 2015 - 2016

    Mobile Developer

    DBServer

    Developed native Android applications using Java (Android SDK) and hybrid apps with Ionic & MEAN stack. Delivered projects for enterprise clients, including Vivo Meu Negócio, Retool, and DBVitae.

  8. 2014 - 2015

    Mobile Application Developer

    SoftMóvel

    Designed, built, and maintained Android applications for business and logistics. Key projects: SivaPlus, SivaGeo, SivaDelivery, SivaTrade.

  9. 2012 - 2013

    Software Developer Internship

    Dell

    Assisted in developing backend solutions for enterprise applications using PL/SQL. Supported system enhancements for internal business operations.

How I work

Engineering philosophy

01

Details compound

A tuned transition, a correct focus ring, one fewer layout shift — individually small, together they read as quality.

02

Ship, then measure

Real users and real metrics beat speculation. I instrument first and let the data guide the next iteration.

03

The best UI is invisible

Interfaces should get out of the way. Speed, clarity and accessibility are features, not afterthoughts.

I hear and I forget. I see and I remember. I do and I learn.
— Confucius

Toolbox

Technologies I reach for

Frontend
  • React
  • TypeScript
  • Next.js
  • Angular
  • React Native
  • Flutter
Backend & Data
  • Node.js
  • Django
  • Python
  • Java
  • PostgreSQL
  • MongoDB
Craft & Tooling
  • Design Systems
  • Web Performance
  • Accessibility
  • Testing (Jest, Cypress)
  • Docker
  • CI/CD

Writing

Notes on frontend & tooling

All posts

Let's talk

Have a role or a project in mind?

Always glad to hear about interesting staff and lead frontend opportunities. The fastest way to reach me is email.

brunohaetinger@gmail.com LinkedIn