Start a project →
Android · Kotlin · Java consultancy

Mobile engineering, done properly.

I'm a senior Android and JVM specialist who designs, builds, and rescues production mobile apps — from Kotlin Multiplatform greenfields to legacy Java modernization.

Book a discovery call See what I do
24+
years on the JVM
Logistics · Telecom · Finance
domains I know
TokenStore.kt
// credentials encrypted at rest, the boring-reliable way
class TokenStore(ctx: Context) {
private val prefs = EncryptedSharedPreferences.create(
ctx, "vault",
MasterKey.Builder(ctx).build(),
AES256_SIV, AES256_GCM,
)
fun save(token: String) =
prefs.edit().putString("auth", token).apply()
}
What I do

Specialist, not generalist. I only do mobile and JVM.

Every engagement is handled personally by one senior engineer who has shipped at scale. No hand-offs to juniors, no offshore surprises.

01

Android app development

Greenfield apps built in modern Kotlin — Jetpack Compose, coroutines, clean architecture, and CI that ships to the Play Store on day one.

KotlinJetpack ComposeCoroutines
02

Kotlin Multiplatform

Share business logic across Android, iOS, and backend with KMP — one source of truth, native UX on every target, less code to maintain.

KMPCompose MPKtor
03

Java modernization

Aging Java codebases brought current — incremental Kotlin migration, dependency upgrades, and test coverage without a risky rewrite.

Java → KotlinSpringRefactoring
04

Audits & rescue

Inheriting a troubled app? I assess architecture, performance, and stability, then deliver a prioritized plan — or take the wheel.

Code auditPerformanceCrash triage
How I work

A predictable path from kickoff to release.

Fixed-scope discovery, then two-week sprints with working software at the end of every one. You always know where things stand.

[ 01 ]

Discovery

I map goals, constraints, and the existing codebase, then scope a realistic plan with clear milestones.

[ 02 ]

Architect

Module boundaries, data flow, and tooling decided up front — so the build stays fast as it grows.

[ 03 ]

Build

Two-week sprints, demoable each time, with automated tests and CI from the first commit.

[ 04 ]

Ship & support

Staged rollout, monitoring, and a documented handover — or an ongoing retainer if you'd rather I stay.

My toolkit

Battle-tested tools, no résumé-driven development.

I pick what's stable and maintainable for your team — and document every choice.

Kotlin Java Jetpack Compose Coroutines / Flow Kotlin Multiplatform Ktor Spring Boot Gradle Room / SQLDelight Hilt / Koin JUnit / Espresso GitHub Actions
Start a project

Tell me what you're building.

Send a few details and I'll get back to you personally — not a salesperson — within one business day.

Email
gustavoamg@gmail.com
Office
Cascais, Portugal
Response
Within 1 business day
No spam. I reply personally.
✓ Message sent.

Thanks — I've got your details and will be in touch within one business day.