Frank Olien
Available for new work

Fullstack engineer
for mobile, web
& onchain.

I'm Opia Frank, a mobile-first software engineer. Flutter & Dart on the front, Rust, Java & Swift on the back, Solana & Ethereum on-chain. Several apps live on the App Store & Play Store.

See my workResume ↗
github/frankolienlinkedin/frank-olienx/frank_olien123

01 / About

A little about me

I'm Frank, an Applied Mathematics graduate from the University of Lagos who fell in love with shipping software. My focus is mobile, but I'm equally at home on the web and writing systems-level backends.

I've worked across AI-driven apps, fintech, Web3 / blockchain, and healthcare platforms, from real-time chat over WebSockets to Solana on-chain programs and Spring Boot wallet backends.

Currently a Blockchain Researcher at EntryPoint Labs, exploring Web3 protocols and AI. Before that I shipped mobile apps for FriendnPal (Africa's first AI mental health app), Feedr, and Méno Bible App.

5
Apps live on stores
6+
Languages I ship in
5+
Production backends
∞
Cups of coffee

02 / Skills

Tech I work with

Languages

  • Dart
  • Rust
  • Java
  • TypeScript
  • JavaScript
  • Swift
  • Solidity
  • C++

Frontend

  • Flutter
  • React
  • Next.js
  • Tailwind CSS

Backend

  • Actix-Web (Rust)
  • Spring Boot (Java)
  • Vapor (Swift)
  • REST
  • WebSockets

Blockchain

  • Ethereum
  • BSC
  • Solana
  • Base
  • Web3j

Databases

  • PostgreSQL
  • MySQL
  • MongoDB
  • Firebase
  • Appwrite
  • Supabase

Cloud & Observability

  • AWS
  • Grafana / Loki
  • Prometheus
  • Datadog
  • Sentry
  • AppSignal
FlutterFlutter
DartDart
RustRust
SolanaSolana
EthereumEthereum
ReactReact
TypeScriptTypeScript
Next.jsNext.js
TailwindTailwind
SpringSpring
SwiftSwift
OpenAIOpenAI
PostgreSQLPostgreSQL
FirebaseFirebase
SupabaseSupabase
SoliditySolidity
VercelVercel
FlutterFlutter
DartDart
RustRust
SolanaSolana
EthereumEthereum
ReactReact
TypeScriptTypeScript
Next.jsNext.js
TailwindTailwind
SpringSpring
SwiftSwift
OpenAIOpenAI
PostgreSQLPostgreSQL
FirebaseFirebase
SupabaseSupabase
SoliditySolidity
VercelVercel

03 / Selected Work

Things I've built

On-chain products, fintech, mobile apps, and the Rust backends behind them. A mix of client work and experiments.

Buyer protection for USDC. Checkout escrows into yield-bearing USYC under hashed, machine-readable refund policies. Disputes resolve deterministically from evidence, and merchants get paid at T+0 from a settlement vault.

ArcUSDC / USYCEscrow
View project Source
Recourse

A dollar account for everyday life. Hold dollars on your phone, send them to anyone by username in seconds for cents, and top up from local currency. Sign in with a passkey, no seed phrase, with recovery built into the product rather than bolted on.

PasskeysDollar paymentsRecovery
View project Source
Xend

Live football predictions with a self-custodial USD₮ wallet. Call live ties, run knockout cups, and manage a fantasy XI. Buy-ins go to escrow, payouts settle on-chain.

Next.jsSolidityArbitrum
View project Source
Predikt

Confidential aid disbursement on Stellar. Beneficiaries prove they qualify and claim USDC without exposing their identity. Groth16 zero-knowledge proofs, verified on-chain.

StellarSorobanZK / Groth16
View project Source
Almoner

Confidential payouts on Canton. Pay every contributor in one batch where each sees only their own line. Privacy enforced by the ledger, not the app.

CantonDamlPrivacy
View project Source
Sotto

Mobile

Cross-platform apps

Solflare

A Solana wallet to deposit, swap, stake, and send SOL and SPL tokens with live balances over Solana RPC.

FlutterDartSolana
Read the case study
Solflare

Binance

A crypto exchange app with a live market watchlist, spot prices, and a trading UI modeled after Binance.

FlutterRESTRealtime
Binance

Qent · P2P Car Rental

A peer-to-peer car rental marketplace for Lagos. Rust + Actix-Web API, React web client, Flutter mobile.

RustReactFlutter
Qent · P2P Car Rental

Recourse · iOS

The native Swift client for Recourse. Pay with protection, watch your protection window count down, and verify onchain proofs from your phone. Built on Arc Testnet with USDC.

SwiftSwiftUIArc
Recourse · iOS

APIs & systems

Backends I've shipped

QVAC SDK

TypeScript · Swift SDK

Local-first AI SDK for building private, peer-to-peer AI apps. Run LLMs, speech-to-text, and translation fully on-device across Linux, macOS, Windows, Android, and iOS.

TypeScriptSwiftOn-device AI
import { QVAC } from "qvac";
const ai = await QVAC.load("llama");
ai.chat("runs fully on-device")
→ no server, nothing leaves the device

Qent API

Rust · Actix-Web

The systems backend for Qent, a peer-to-peer car rental marketplace. Rust and Actix-Web services for listings, bookings, and payments.

RustActix-WebREST
cargo run -p qent-api
  Actix-Web listening on :8080
GET  /cars       200
POST /bookings   201

Invoice Platform

Rust API

A billing and invoicing backend written in Rust. Create invoices, track their status, and settle payments through a typed REST API.

RustRESTBilling
cargo run
  invoice-platform :8080
POST /invoices      201
GET  /invoices/:id  200

Springten

Java · Spring Boot

A Spring Boot Web3 crypto wallet backend. Custodial wallet services, on-chain transfers, and balance tracking wired to Solidity contracts through a clean REST API.

JavaSpring BootSolidity
mvn spring-boot:run
  Tomcat started on :8080
POST /wallet/create    201
POST /wallet/transfer  200

ClobDex

Rust · Solana

A crankless on-chain order book on Solana. Post, cancel, and fill in one transaction, with no crank, no oracle, and no custody. Native Rust program with a deterministic matching engine and a market maker that quotes a full ladder in 4,639 compute units.

RustSolanaOrder Book
cargo build-sbf
cargo test --workspace
  285 passed · incl. fuzzing
→ post / cancel / fill in one tx

Tostoy

Java · Spring Boot

A comprehensive Spring Boot REST API for healthcare. Hospital search, pharmacy locator, doctor finder, and diagnostic-centre lookup with global coverage.

JavaSpring BootREST
mvn spring-boot:run
  Tostoy API on :8080
GET /hospitals?q=lagos  200
GET /pharmacies/near    200

Live on the stores

Apps live on the Play Store

FriendnPal
FriendnPal
AI Mental Health
Bebe
Bebe
Widget Couple App
Méno
Méno
AI Bible Study
Clawkin
Clawkin
Cat Care Companion
LoveUp
LoveUp
AI Dating

04 / Contact

Let's build something.

I'm open to freelance, full-time roles, and interesting collaborations, especially in mobile, Web3, and AI.

Frankolien123@gmail.com
Email
Frankolien123@gmail.com
GitHub
github.com/frankolien
LinkedIn
linkedin.com/in/frank-olien
X / Twitter
x.com/frank_olien123