Open to remote roles and freelance projects

Jonas BercholFull-stack engineer.TypeScript, .NET, infrastructure and DevOps.

I build and run SaaS products end to end: APIs, real-time messaging, background queues, web and mobile frontends, and the Kubernetes clusters they run on. I have been writing code since I was nine and shipping production software since 2021.

Curitiba, Brazil · UTC−3 · English and Portuguese

Portrait of Jonas Berchol

// services

Hire me for anything code

Full-time role, contract or one-off project. If it runs on a server, a browser or a phone, I can build it, ship it and keep it running, or take over a legacy codebase and fix what is on fire.

Backend and APIs

REST and WebSocket APIs, background jobs and third-party integrations that hold up under load.

  • NestJS
  • .NET
  • Node.js
  • Go
  • Python
  • Socket.IO
  • BullMQ
  • RabbitMQ

Web and mobile apps

Fast, maintainable frontends, from internal dashboards to customer-facing products.

  • React
  • Vite
  • TanStack
  • Redux
  • React Native
  • Expo

Messaging and bots

WhatsApp, Telegram, Instagram and Facebook channels, omnichannel inboxes, chatbots and automations.

  • WhatsApp Cloud API
  • Baileys
  • Whatsmeow
  • Telegram
  • Instagram
  • Webhooks

Infrastructure and DevOps

Containers, clusters, CI/CD pipelines and cloud setups you can actually operate.

  • Docker
  • Docker Swarm
  • Kubernetes
  • k3s
  • GitHub Actions
  • AWS
  • Azure
  • Cloudflare

Data

Schema design, migrations, imports and query tuning across relational and document stores.

  • PostgreSQL
  • MariaDB
  • MongoDB
  • Redis
  • Prisma
  • TypeORM

Desktop and game tooling

Native tools, overlays and game-server plugins, rooted in a technical degree in game programming.

  • C++
  • C#
  • Dear ImGui

// selected work

Production systems

ChatLabel

Omnichannel messaging SaaS · Hubcon

Hubcon’s large-scale, high-availability customer service platform. I work across the .NET backend, the React frontend, channel workers in Node.js and Go (WhatsApp, WhatsApp Cloud API, Telegram, Facebook, Infobip) and the Kubernetes infrastructure behind it.

  • .NET
  • React
  • Node.js
  • Go
  • k3s
  • Redis

Rapid

Marketing platform

Monorepo with a NestJS REST and Socket.IO API, BullMQ workers with a Bull Board UI, a React SPA and a shared domain library. Deployed on Kubernetes with self-hosted GitHub Actions runners.

  • NestJS
  • BullMQ
  • TypeORM
  • React
  • Kubernetes

OtimusClinic API

Healthcare integration

Integration API connecting the OtimusClinic platform to external services, rebuilt as a second version in TypeScript.

  • TypeScript
  • Node.js
  • REST

// products and side projects

Things I build for myself

Household finance planner

In development

Facilitoo

Aggregates bank accounts and credit cards through Open Finance, reads card bills, categorizes spending and adds budgets, goals and cash flow forecasts, shared within a household.

  • NestJS
  • PostgreSQL
  • Prisma
  • React
  • Expo
  • Open Finance

Telegram bot

Live, private

Kindle Converter Bot

Converts images, PDFs and MOBI files to EPUB with Calibre and emails them straight to each user’s Kindle. License-key access with admin tooling.

  • TypeScript
  • Telegram
  • PostgreSQL
  • Docker

Open source CLI

Open source

json-to-postgresql

Imports JSON collections into PostgreSQL, auto-detecting column types and creating one table per collection.

  • Bun
  • TypeScript
  • PostgreSQL

Gaming side project

Side project

CS2 server tooling

Web panel and game-server plugins for a community Counter-Strike 2 server: React and MUI frontend, NestJS on Fastify backend.

  • React
  • MUI
  • NestJS
  • Fastify
  • PHP

// experience

Where I have worked

  1. Apr 2022 – present

    Full-stack Developer

    Hubcon

    ChatLabel omnichannel SaaS, infrastructure and DevOps

  2. Dec 2021 – present

    Full-stack Developer

    Spannel Soluções Integradas

    Web platforms, marketing tools and integrations

  3. Mar 2020 – May 2023

    IT Support Analyst

    Loupen

  4. Apr 2020 – Dec 2020

    IT Support Analyst

    TI Solutions

// education

B.Sc. in Information Management

Federal University of Paraná (UFPR)

2020 – 2022

Technical degree in Digital Game Programming

Federal Institute of Paraná (IFPR)

2016 – 2019

// contact

Have a role or a project in mind?

Tell me what you are building. I usually reply within a day.