Denis VacaruADV IT SOLUTIONS
7+ years Android · personal apps & contract work

Everything I've built.

Two kinds of work: apps I own end to end, and Android contracts for other companies' products.

Personal apps

Mine, end to end.

Product, engineering, ASO, and growth — all owned solo.

LiveFlutter · Android · iOS

Solfeggio: Healing Frequencies

A sleep and relaxation app, rebuilt around outcomes.

A frequency-based relaxation and sleep app offering solfeggio tones, ambient noise, and guided breathing. I owned it end to end: content catalog architecture, subscription monetization, and ASO. Rebuilding the store listing around outcome-led messaging moved core search terms into the top 2–12 on Google Play, and the app holds a 4.7★ rating across 750+ reviews.

FlutterFirebase Cloud FunctionsFirebase StorageFirestoreRevenueCatAmplitudeGoogle Ads
LiveFlutter · Android · iOS

Inward

A guided meditation app built around a breathing-orb identity.

Inward pairs guided meditation and sleep stories with a distinctive visual identity centered on a breathing orb. I designed and built the full onboarding flow, implemented dynamic paywall logic with Superwall, and set up funnel instrumentation across Amplitude to track and optimize engagement from first session to subscription.

FlutterFirebase Cloud FunctionsFirestoreSuperwallRevenueCatElevenLabsAmplitude
LiveFlutter · Android · iOS

Gloam

A voice-first journal, private by design.

A private journal that transcribes entries on-device (local Whisper) and encrypts them at rest, built around privacy as its core differentiator. I led the competitive research, designed an AI-assisted mood-detection system from transcript analysis, and built the full design system, ASO listing, and acquisition strategy from scratch.

FlutterFirebase Cloud FunctionsFirestoreLocal WhisperSQLCipherRevenueCatSuperwallOpenAI API

Contract work

Also building for other teams.

Since 2021 I've worked as a freelance/contract Android developer through ADV IT Solutions — mostly fintech apps for European banks, and media streaming.

OngoingContract · Android native · Jun 2022–Present

Bookly

Turned a struggling 3.6★ app into a solid 4.4★, as its solo Android contractor.

I took over Bookly's Android codebase — a reading tracker with 2M+ users — when it was in poor shape: frequent freezes, slow performance, core features not working properly, and a 3.6★ US rating. Over time I refactored large portions of the code (migrating most of the old MVP structure to MVVM + Clean Architecture), optimized performance, fixed the core feature set, and introduced CI/CD with Bitbucket Pipelines to automate builds, testing, and releases. The rating peaked at 4.5★ and now holds steady at 4.4★ — and Android revenue has grown roughly 500% since taking over, nearly doubling year over year.

KotlinMVVM + Clean ArchitectureCoroutines / RxJavaAndroid JetpackFirebaseFirebase FunctionsLaravelBitbucket CI/CD
CompletedContract · Android native · Aug 2022–Aug 2023

DAZN

Merged the mobile and Android TV codebases for the sports streaming app.

Worked across both the mobile and Android TV applications, merging two codebases built on different tech stacks by leaning on both apps' modularized architecture to integrate and adapt mobile features into the TV app. Involved in feature implementation, code review, technical decisions, estimations, and releases. Also owned Play Store releases and monitored user feedback and analytics post-release.

KotlinMVVM / MVP + Clean ArchitectureAndroid JetpackDagger / HiltCoroutines / RxJavaRealm SDKParse SDKNew RelicUnit & UI testing
CompletedContract · Android native · Jun 2021–Dec 2021

BRD - Groupe Société Générale

Worked on the new You BRD banking app — feature development and bug fixes.

Contracted through an external firm to work on the newly built You BRD mobile banking app. Involved in developing features and fixing bugs as part of the Android team.

Kotlin / JavaMVPBackbase SDK
CompletedContract · Android native · Feb 2022–Jul 2022

Cembra

Joined Cembra's Android banking app in its early stage.

A short-term contract engagement on Cembra's Android banking app while it was still in an early stage. Actively participated in technical decisions and feature implementation.

KotlinMVVMBackbase SDK