OPEN TO OFFERS Senior Backend · Senior Software Engineer roles in Spain, Portugal or Ireland

Rodrigo Orth Karwinski

Senior Software Engineer

I build and maintain backend services, APIs and integrations for financial systems, payments, e-commerce and iGaming. I modernize legacy systems and help teams raise their engineering standards.

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10+ yearsbuilding software professionally
Malta, EuropeCET, same time zone as Spain; ready to relocate
Paymentscards, 3DS, Pix, reconciliation, ledgers
Tech leadled teams and mentored junior and mid-level developers
Who I am

Backend engineer who likes the hard parts of a system.

I started in technical support in 2012, moved into PHP development, and have spent the years since building backend systems in Brazil and Europe. Today I work at Betsson Group (Zecure) in Malta, on integrations and internal systems in the iGaming ecosystem.

Most of my work sits where money moves: payment transactions, reconciliation and settlement, financial and tax integrations, Pix instant payments. I design microservices with event-driven architecture and CQRS, and I care about how software behaves in production: tracing, dashboards, alerts, incident response and post-mortems.

I've been a tech lead twice, and I still enjoy code review and mentoring. I use AI coding tools every day, always validating what they produce, and I help my current team build shared guidelines and specs for working with AI coding agents.

What I do

Four areas I'm hired for

Backend architecture

Microservices, event-driven systems and CQRS. RESTful APIs used by internal and external platforms, with API versioning and data migrations in every role since 2017.

HexagonalCQRSKafkaRabbitMQRedis Streams

Payments and financial integrations

Card and cash transactions, 3-D Secure, reconciliation, settlement, refunds, chargebacks, disputes and ledgers. Pix integration for Brazilian instant payments.

3DSPixLedgersTax integrations

Production and reliability

Monitoring, metrics and alerts, distributed tracing, on-call and incident response. Circuit breakers and feature toggles to isolate failures.

OpenTelemetryDatadogGrafanaKubernetes

Engineering practice

Legacy refactoring and technical debt reduction, TDD, design docs and ADRs, code review and mentoring. Daily AI-assisted development with GitHub Copilot, OpenAI Codex and Claude Code.

TDDADRsMentoringAI coding agents
Selected result · Pravaler

Boleto registration: 6 hours down to 20 minutes, R$100k down to R$10k a year.

Boletos (Brazilian payment slips) were registered for every month in advance, and any change meant cancelling all of them and registering them again. I built a service that registers only the boletos due in the next 20 days, so nothing is registered before it is needed. I also rewrote the old PHP 5 service in Node.js, running registrations concurrently with Promises.

Infrastructure costs dropped sharply as well.

Experience

2012 → today

Pick a technology to see where I used it.

  1. Jul 2025
    — now
    Betsson Group · ZecureSenior Software EngineerHybrid, Malta
    • Integrations and internal systems in the iGaming ecosystem with PHP (Laravel, Symfony, Filament), React, Vue.js and TypeScript.
    • Delivered the third-party KYC and geolocation integrations for the group's newly launched Ontario brand, built to meet the requirements of a strictly regulated market.
    • Integrated gamification mechanics across the group's brands, including Peru, Malta, Serbia and Croatia, bringing a consistent player engagement experience to multiple regulated markets.
    • Helping build the team's practice of working with AI coding agents.
    PHPReactTypeScriptKafkaRedisMySQLAWS
  2. Jun 2024
    — Jul 2025
    Atlas TechnolSenior Software EngineerRemote
    • Payments team: card, cash and other transaction services, including 3-D Secure authentication.
    • Reconciliation, settlement, refunds, chargebacks, disputes and ledgers.
    • Microservices and RESTful APIs; ADRs for database changes and new features.
    PHPLaravelRedisElasticSearchKafkaGCP
  3. Mar 2022
    — Dec 2023
    PravalerSoftware EngineerRemote
    • Financial integrations and internal services with PHP, Python, Node.js (NestJS) and TypeScript.
    • Cut boleto registration from about 6 hours to 20 minutes and its cost from R$100k to R$10k a year.
    • Microservices with CQRS and event-driven architecture; performance work on high-load systems.
    • CI/CD pipelines and infrastructure as code with Terraform.
    Node.jsNestJSTypeScriptBoletosMongoDBPostgreSQLAWS
  4. Jun 2021
    — Mar 2022
    aiqfomeFinance Software EngineerRemote
    • Financial and payment systems with PHP, Node.js and Python.
    • Pix integration for Brazilian instant payments.
    • SQL query and schema optimization in high-transaction systems.
    PHPNode.jsPythonPixGCP
  5. Sep 2019
    — Jun 2021
    InfoarIntegration Back-End Developer (Tech Lead)Porto Alegre, Brazil
    • Led financial, tax and e-commerce integrations; owned systems that handled very high Black Friday traffic.
    • Built a freight quotation system in Go for high request volume.
    • Led incident response on call and supported junior and mid-level developers.
    PHPGoOracle Commerce CloudDocker
  6. Sep 2017
    — Jul 2019
    WebGlobalFull Stack Developer (Tech Lead)Porto Alegre, Brazil
    • Internal systems and e-commerce platforms; Oracle Commerce Cloud integrations.
    • Led a small development team and projects spanning multiple teams.
    PHPJavaScriptMySQLPostgreSQLAWS
  7. 2012
    — 2017
    Where it started
    • PHP Developer at Conecta IT (2017), OrthoMundi (2016) and Agência S3 (2016).
    • Technical Support at CESUCA Faculdade Inedi (2012 – 2015).

Side projects

Built outside work
LLM · TypeScript

Help My Moving

Helps people decide what to take, sell or donate when moving. Turns a free-text item description into estimated dimensions and a take-or-sell suggestion as structured JSON, using an LLM API.

TypeScriptMySQLRedisLLM API
LLM · Python

News Digest for E-Readers

Collects news from RSS feeds, summarizes it with an LLM in Portuguese, English and Spanish, and generates EPUB files for Kindle. Tracks LLM cost, tokens and latency.

FastAPIpgvectorOpenTelemetryLangfuse
Finance · Vue.js

Smart Finance

Personal finance system for people with income in two or more currencies: savings, investment returns, monthly bills, credit card statements and a dashboard.

Vue.jsPHPPostgreSQL
Small business · Laravel

Rent

Car and trailer rental management for a friend's micro-business, with contracts and reservations. Built twice: first in CakePHP, then rebuilt in Laravel and Filament.

LaravelFilamentRedis

Stack

Used in production

Languages

PHPTypeScriptJavaScriptNode.jsPythonGo

Frameworks

LaravelSymfonyFilamentCakePHPPhalconPHPNestJSReactVue.js

Data

MySQLPostgreSQLMongoDBRedisElasticSearch

Messaging & auth

KafkaRabbitMQRedis StreamsPub/SubJWTOAuth

Cloud & delivery

AWS (ECS, Lambda, S3, IAM)GCPDockerKubernetesTerraformCI/CD

Observability

OpenTelemetryDatadogGrafanaKibana

Testing

PHPUnitJestCypressTDD

AI tools

GitHub CopilotOpenAI CodexClaude CodeChatGPT

Education

Postgraduate Specialization in Data ScienceDescomplica Digital College · Completed
Bachelor's Degree in Systems Analysis and DevelopmentDescomplica Digital College · Completed