Skip to content
RC
Let's talk

Rafael Cuevas — Web & mobile apps · Electronic engineer

Available for projects

From the chipto the app.

Web and mobile apps, plus the electronics behind them. I design every layer, from circuit to cloud to screen, so your connected product works as one system.

View my work
years building apps
6+
apps delivered
30+
IoT projects
15+
  • Next.js
  • TypeScript
  • iOS
  • Android
  • Flutter
  • Dart
  • BLE
  • Circuit design
  • PID control
  • Microcontrollers
  • Sensors
  • Firebase
  • Firestore
  • Cloud Functions
  • Google Cloud
  • SQLite / Drift
  • Kotlin
  • Swift
  • C#
  • HealthKit
  • Google Fit
  • Figma

About

An engineer who reads both the datasheet and the design file.

I studied electronic engineering, so my first programs ran on microcontrollers, not phones. At university I built robots: sensors, motors, boards and the code that moved them. That habit stuck. Today I build web and mobile apps, and I still start by asking how every part of a system connects. My favorite projects are the ones where hardware and software have to talk.

15+

IoT projects where the app was one piece of the system

  • Electronic engineer by training
  • Remote, with clients across the Americas
  • English & Spanish

Analyzing the integration

Five layers. One person who sees the whole path.

Most connected products fail between layers, not inside them. I work across all five.

  1. L1

    Circuits & sensors

    Design circuits and control loops (PID) so the device measures and acts with precision.

    15+ IoT builds · university robotics

  2. L2

    Firmware

    Understand the device protocol and its limits (packets, timing, power) so the app asks for data the right way.

    Valyant: built on the ring's custom BLE SDK

  3. L3

    Connectivity

    Keep BLE and Wi-Fi links alive in the real world: dropped connections, background limits, retries.

    Valyant: auto-reconnect with exponential backoff

  4. L4

    Backend & cloud

    Move data from device to cloud without losing it: offline-first storage, sync rules, real-time streams.

    Valyant: SQLite ⇄ Firestore sync in 500-record batches

  5. L5

    App & web

    Turn raw readings into screens people understand and trust, on iOS, Android and the web.

    30+ apps shipped · Pharma B2B on web and mobile

Services

What I build

  • What you get
    A mobile app with a BLE layer that reconnects on its own, offline-first storage and a cloud backend.
    Example
    Valyant smart ring

  • What you get
    Circuit design, control systems (PID), firmware integration, backend and app, owned by one person. Robotics prototypes included.
    Example
    15+ IoT projects · university robotics

  • What you get
    One production app: layered architecture, security from day one, real-time features, payments and store release.
    Example
    Realay · SSGB · Ubetcha

  • What you get
    Web apps that share logic with your mobile app, or fast Next.js sites that search engines can read.
    Example
    Pharma B2B on web, Android and iOS

Selected work

Products in the wild

Most client work is private. These are the projects I can show.

How I think

Method over adjectives.

  1. 01 / 04

    Map the system first

    I trace where data is born, travels and lands before writing code. Skipping this map breaks estimates.

  2. 02 / 04

    Bugs live in the seams

    When hardware and software disagree, the fault is usually between layers: timing, formats, lost connections. I look there first.

  3. 03 / 04

    Design for the bad day

    Bluetooth drops, users go offline, the OS kills the app. I build recovery before the happy path.

  4. 04 / 04

    Structure is a feature

    A clear architecture lets the next feature ship in days, not weeks. I set it up on day one.

What we could build together

Ideas my skills already point to.

Possibilities, not past projects.

  • Possibility

    Connected medical devices

    Wearables or bedside devices that stream vitals to patients, clinicians and the cloud.

    Built on: BLE health data (Valyant)

  • Possibility

    Remote equipment monitoring

    Sensors on machines that report status and alert your team before something fails.

    Built on: IoT builds + real-time apps

  • Possibility

    Fleet & asset telemetry

    Trackers and driver apps that show where every vehicle or asset is, and what state it is in.

    Built on: Fleet app (TLE) + BLE

Have a product where hardware and software need to talk? Let's build it.

Tell me what you're building and where it gets stuck.

Let's talk