2026 · NOW

Design Engineer · Rio de Janeiro · UTC−3 · PT / EN

Alexander Cesar

I take approved designs to production frontend — and build my own products from scratch. Design and code, in the same hands, for nearly thirty years.

Available for remote contract work

2025 — 26

Through OPTEN AG, Switzerland

From Figma to merged PR.

projects delivered

months

stacks

Frontend implementation for client projects commissioned through OPTEN AG, Switzerland. I take approved designs and deliver tested, accessible UI code — components, modules, and frontend architecture — across Angular, React Native, Umbraco, HTMX and Razor.

7 projects

Single player skating on the ice, mid-stride

National Sports Federation Platform

Mar–May 2026

Frontend module library from approved designs — token-based CSS architecture and a statistics-driven game center with live standings.

Umbraco 17.NET 10HTMX

Building facade under construction with insulation wrap and crane

Manufacturer CMS Platform

Feb–Mar 2026

CMS module system with responsive page previews — reusable Razor components with content fallbacks, so editors can’t break a layout.

Umbraco 17Razor

Floodlit pitch from above during an evening match

Sports League Production Platform

Jan–Mar 2026

TV production dashboard and match views, built against an agreed JSON contract so frontend and backend moved in parallel.

AngularASP.NET

Red wine being poured into a glass at the table

Voice Ordering App

Sep 2025–Feb 2026

Voice-first wholesale ordering on iOS, Android and web — recording UI with a retry queue, multi-step checkout, DE/EN.

React NativeExpo

AI Assistant Interface

Sep 2025

Streaming chat with reactions and attachments — state on Angular Signals, overlays through CDK.

Angular 20Signals

Open-plan office with people at workstations

Enterprise Customer Portal

Jul–Sep 2025

About fifteen reusable components assembled into ten-plus portal sections, mock-first so the frontend never waited on the backend.

Angular 17Umbraco

Industrial worker with safety helmet and goggles

Workplace Safety Heatmap

Jul 2025

A Figma design system implemented as working Angular components, true to the tokens and interaction specs.

Angular 17

Showing 7 of the 12. All work commissioned and led by OPTEN AG, where I contributed in a frontend development capacity — UI implementation, component development, and UX improvements.

2025 — 26

Own products

Designed, built and shipped end to end.

Idea, design, code, deploy — with AI agents as part of the workflow. Alongside: a software-engineering postgrad (AI focus) at PUC Minas.

Live on Vercel

Holter Log

A clinical diary for the 24-hour Holter cardiac exam. The patient taps when a symptom hits; it lands timestamped on the doctor’s dashboard.

Vanilla JSSupabasePWA

In development

EcoDrive

Snap the fuel-pump display — Claude Vision reads liters, price and total. No manual input.

React NativeClaude API

In development

PromptNinja

Turns rough ideas into structured prompts. Full-stack on Cloudflare Workers at near-zero infrastructure cost.

HonoCloudflareStripe

2022 — 24

CESAR

Design systems at scale.

Global consumer electronics company Under NDA

One full year on CESAR’s highest-value engagement — a design system and reusable component libraries, implemented across React, Angular and EmberJS with accessibility-first architecture.

Energy and technology clients

Component libraries and frontend work across the same three frameworks.

2021 — 22

Legal-tech startup

A startup, from research to investor-ready.

Immigration-planning MVP

Led UX from discovery research to an investor-ready MVP for planning a move to another country — launched in 12 weeks.

Immigration-planning platform home screen — fig. 2021 — immigration-planning MVP

2019 — 21

Eleva Educação

Education, under lockdown.

120k

students served

2 weeks

to redesign Canal Eleva in the pandemic

Canal Eleva

The Canal Eleva video platform, redesigned in two weeks when COVID closed the schools.

Avaliação Formativa

A weekly assessment system: teachers and coordinators track results, spot difficulty areas, and run personalized online tutoring.

Student tutoring session screen — fig. 2020 — personalized tutoring, teacher to student

Design System Fibo

The design system behind both platforms — tokens, components and patterns.

Fibo design system overview — fig. 2020 — Fibo design system

2006 — 15

Petrobras · via Atos Origin, Politec, Indra, Atos

The corporate web.

LOPE — people finder

~$5M

saved per year

4min → 90s

building access time

LOPE replaced every people-finding tool across Petrobras worldwide with one search — and was the company’s first fully accessible application, tested with visually impaired users.

LOPE people finder — search home screen — fig. 2013 — LOPE, one search for a worldwide workforce

Programa Petrobras Cultural

Built the first three editions (2006–2008) of the cultural sponsorship platform — the program still runs today.

Fcorp Design

The company’s first corporate design framework — standardized the visual identity of internal apps across .NET, Java, Python and JavaScript.

Design Acessível — own studio, in parallel (2013–18)

SIGSAUDE for the Brazilian Navy, a Kawasaki dealer platform and the Arena On eSports platform.

Design Acessível studio work overview — fig. 2013–18 — Design Acessível, accessibility-first studio

core sample ends · first line of code, 1997

Work with me.

Available for remote contract work. Monthly invoicing, daily or weekly rate.

Book a call

Pick a slot that works in your timezone — video, straight to my calendar.

The fastest way to reach me directly.

Chat on WhatsApp →

LinkedIn · GitHub · Behance

Sheet: PORTFOLIO / 01
Drawn by: A. CESAR
Checked by: FABLE 5 (AI)
Scale: 1997 → 2026
Rev: 2026.07