Full-stack developer

Adonis Xiao

I build production SaaS — bookings, billing, and real-time systems.

Florina, Greece · Remote

View Exeltiq Download resume

Exeltiq is live

Adonis Xiao Full Stack Developer Engineer portrait

Work

Live product, then the contract that preceded it.

exeltiq.comlive

Today’s schedule

09:00
HIIT Burn
Maria
18/20
11:30
Reformer Pilates
Andreas
12/12
18:00
Strength Lab
Yiannis
15/24

Product UI reconstructed from the public Exeltiq site.

01 · Sep 2025 – Jun 2026

Exeltiq

Multi-tenant CRM for gyms, clinics, and sports clubs in Cyprus. Primary builder. Greek + English. Paid Stripe plans.

Auth: Clerk JWT for owners and members in a multi-tenant club.
Billing: Stripe for plans, SMS credits, packages, and shop checkout.
Booking: Buy a package, redeem it for fitness, physio, or grooming.
Messaging: Stripe → credits → Twilio. Referrals discount a month, never cash.

Open the live product →

02 · Mar 2025 – Jul 2025

Corva.ai

Hackathon, then contract backend through project completion on an oil-and-gas real-time platform.

High-volume operational data for live dashboards
WebSockets and async status so job stages did not drift

corva.ai →

Job pipeline · websocket

01ingestdone
02normalizedone
03streamlive
04dashboardwaiting

Representation of the status flow.

Experience

Before Exeltiq

2023 – 2025

Emerton

Senior Full-Stack Engineer (Contract), Remote

~7 business and startup clients. React / Next / TypeScript + FastAPI / Node. Auth, payments, APIs. Independent delivery.

2021 – 2022

ACLIT

Backend Developer (Contract), Remote

REST (Node, Express, Python). JWT/OAuth. PostgreSQL, MySQL, MongoDB. Swagger / Postman.

2020 – 2021

GMO Internet Group, Japan

Frontend Engineer

gmo.jp

React + TypeScript UI, reusable components, production frontend.

2018 – 2020

TechWave Solutions

Junior MERN Stack Developer

React, Node, Express, MongoDB. AWS EC2, PM2, Nginx.

2016 – 2020

Central South University, Changsha

B.S. Computer Science

Education.

About

One engineer owns the product.

Seven-plus years building production web apps — mostly inside founder-led teams where one engineer owns the product, the billing, and the 2 a.m. bug.

Recent work is Exeltiq: a live multi-tenant CRM with real money through Stripe and real messages through Twilio. Before that: Corva’s real-time stack, two years at Emerton across about seven clients, backend APIs at ACLIT, frontend production at GMO in Japan, and a MERN start at TechWave. Computer Science at Central South University, Changsha.

I care about state that does not drift — credits, jobs, bookings.

Next.jsReactTypeScriptFastAPIPythonNode.jsExpressPostgreSQLSupabaseMongoDBMySQLClerkStripeTwilioOpenAI APIWebSocketsAWSDockerCI/CD

Contact

Florina, remote. Available for the next build.

adonisdev313@gmail.com Download resume