Rafael C. Rafael A. Carrascal Reyes Email

Backend Systems Engineer · Ruby on Rails / Python · Colombia (remote)

Rafael A. Carrascal Reyes

15+ years building mission-critical financial and insurance platforms, 6 of them in regulated banking. I build well-tested backends and data pipelines — and I use AI agents to build them faster.

See RentaFIC Email me See my work
Years in technology
15+fintech & regulated banking
Colombian FICs tracked
900+real, inflation-adjusted returns
Users served at Monokera
5,000+across 5 insurance products

Featured project

Work that answers a question nobody else asked

Live · Founder & Lead Engineer, 2026

RentaFIC

Real returns of Colombian FICs & FPVs

Colombian investors compare nominal fund returns — a number that is inflated by inflation and quietly reduced by fees. RentaFIC recalculates the real cumulative return of 900+ FICs and 500+ FPVs, monthly. No competitor in Colombia publishes inflation-adjusted figures.

Data comes from Colombia's open government portal (datos.gov.co) and official SFC filings — neither offers a clean API. A PySpark pipeline normalises and joins the sources into Supabase, a Streamlit frontend serves the public rankings and per-fund analysis, and a Mistral-powered chatbot answers fund questions in natural language. Deployed with Docker on a VPS, updated by GitHub Actions + Watchtower.

Read the case study Live site GitHub
FICs tracked
900+
FPVs tracked
500+
refresh cadence
Monthly
  • PySpark pipeline sourcing datos.gov.co + official SFC data
  • Mintlify-inspired Streamlit UX — public ranking plus per-fund analysis charts
  • Supabase authentication and user management
  • Mistral-powered AI chatbot for fund questions
  • Docker on VPS with GitHub Actions + Watchtower for zero-downtime updates
  • Spec-driven, AI-assisted workflow (Claude Code + OpenCode)

Stack

Python PySpark Streamlit Supabase Mistral Docker GitHub Actions

About

Backends, data pipelines, and the boring parts that keep them honest

Backend systems engineer with 15+ years building mission-critical financial and insurance platforms. 10 years of Ruby on Rails, plus Python and PySpark for data pipelines at scale.

I spent the first six years in the Systems Division of Corficolombiana, inside Colombia's second-largest banking group — transactional and batch systems, financial calculations and reporting. Where a rounding error is a compliance incident, you learn to write tests over money-handling code first and ask questions about idempotency second.

Since then: loan origination at LendKey, insurance underwriting at Monokera, and five years of independent consulting across Europe and LATAM. I have owned CI/CD end to end, taken a backend team through a product launch, and shipped a schema change that bought back 40% of its query time.

Throughout, AI-assisted development has been a working practice rather than a talking point — context management, cost control for agents, and an honest read on where LLMs help and where they quietly do not.

Role
Backend Systems Engineer — Rails / Python
Based
Colombia · remote, US/EU overlap
Domain
Fintech · Insurtech · regulated
Languages
Spanish (native) · English (professional)

Also works with

REST APIs Microservices RabbitMQ Streamlit Supabase Shopify / Liquid Angular / Ionic Jenkins Agile / Scrum Code review Jira / Linux Claude Code OpenCode Mistral

Stack

What I reach for, and where I have actually used it

No self-assessed percentages. Each entry below is a tier, an approximate number of years in production, and a specific thing I built.

Ruby on Rails
core
10 yrs
Production Rails backends across fintech, insurtech and e-commerce; 5 products at Monokera.
Python / PySpark
core
4 yrs
PySpark pipeline ingesting and transforming datos.gov.co — 900+ funds refreshed monthly.
PostgreSQL
core
7 yrs
JSONB schema design for policy data, improving query performance by 40%.
RSpec / TDD
core
7 yrs
High-coverage suites maintained over regulated lending and money-handling code paths.
AWS / Docker / CI-CD
proficient
5 yrs
Lambda + S3→SFTP transfer with zero data loss; Docker on VPS; GitHub Actions, Watchtower, Jenkins.
AI-assisted development
proficient
2 yrs
Spec-driven workflow with Claude Code and OpenCode; Mistral integration in production.
JavaScript / Angular / Liquid
working
4 yrs
MVPs in Angular and Ionic; Shopify storefronts and admin UI at CINTE Iberia.
Java
working
8 yrs
Enterprise systems and microservice integrations at Corficolombiana and Grupo Ditech.

Languages

Ruby Python Java JavaScript SQL Bash

Frameworks

Rails PySpark RSpec Streamlit Angular Ionic Liquid

Data

PostgreSQL JSONB Supabase datos.gov.co SFC filings

Infrastructure

AWS Lambda S3 SFTP Docker GitHub Actions Watchtower Jenkins

Practice

TDD CI/CD ownership Clean Code Code review Full SDLC Agile / Scrum Spec-driven dev

Experience

Fifteen years, six engagements, one industry

  1. 2026-04 → Present ongoing

    Founder / Lead Engineer

    RentaFIC Own project — open data analytics

    900+ FICs tracked monthly

    Open-data analytics platform built from the ground up, sourcing Colombia's public financial datasets and delivering actionable insight through AI-augmented reporting.

    • PySpark pipeline ingesting and transforming datos.gov.co at scale
    • Mistral chatbot for natural-language data exploration and report generation
    • Supabase auth, role-based access control and multi-tenant user management
    • Docker on VPS with GitHub Actions + Watchtower for zero-downtime updates
    • Built with a spec-driven, AI-assisted workflow (Claude Code + OpenCode)
    Python PySpark Streamlit Supabase Mistral Docker

  2. 2023-06 → 2026-04 2 yrs 10 mos

    Ruby Back-End Developer

    Monokera Insurtech

    5,000+ users, 5 products

    Core backend engineer on financial and insurance products serving thousands of policies across LATAM markets (Peru, Colombia) for multiple enterprise clients. Owned the CI/CD pipeline end to end.

    • Bidirectional S3→SFTP transfer on AWS Lambda + Python, thousands of policy files per week with zero data loss — retry logic and structured error handling
    • PostgreSQL schemas with JSONB columns for flexible policy data, improving query performance by 40%
    • Release cadence from bi-weekly to multiple times per week
    • Full SDLC ownership in a Linux/Jira environment — planning, review, production monitoring
    Ruby on Rails PostgreSQL AWS Lambda Docker

  3. 2021-01 → 2023-06 2 yrs 5 mos

    Backend Engineer

    Encora Inc. — LendKey Fintech

    Regulated lending platform

    Origination modules for a US digital loan platform in a highly regulated fintech environment. End-to-end delivery under Agile/Scrum.

    • Loan origination logic and repayment schedule engines
    • Integrations with financial data providers in Ruby on Rails
    • High RSpec coverage maintained over compliance-sensitive code paths
    • Async collaboration across US, India and Costa Rica
    Ruby on Rails RSpec PostgreSQL

  4. 2015-03 → 2020-11 5 yrs 8 mos

    Engineering Consultant

    Independent Engineering Consultant Self-employed · Europe & LATAM

    Startups & enterprise clients

    End-to-end engineering for startups and enterprise clients across Europe and LATAM — fintech, insurtech and e-commerce. Clients included CINTE Iberia (Rails and Shopify/Liquid for European enterprise) and early-stage startups (MVPs in Rails, Angular and Ionic). Modernised legacy Rails codebases and migrated teams to containerized deployments.

    Ruby on Rails Angular Ionic Shopify/Liquid Docker

  5. 2019-01 → 2020-12 2 yrs

    Backend Engineer — Tech Lead

    Grupo Ditech — Yuse InsurTech Insurtech · Youse.com.br (Brazil)

    Brazilian market launch

    Technical lead for backend services on the Youse.com.br insurance platform. Architected microservices with RabbitMQ and designed the automated testing strategy that raised reliability ahead of a major product launch.

    Microservices RabbitMQ

  6. 2009-03 → 2015-04 6 yrs 1 mo

    Enterprise Systems Engineer

    Corficolombiana Grupo AVAL — regulated banking

    6 yrs regulated banking

    Six years in the Systems Division of Colombia's second-largest banking group. Designed and built internal applications optimising back-office operations — transactional systems, batch processing, financial calculations and reporting — working directly with functional leaders across business units.

    C# ASP.NET Java COBOL/DB2

Writing

Notes from the work

Contact

Open to backend and AI-engineering roles

Colombia-based, comfortable with US and EU overlap. If you are building backends in fintech or insurtech — or you have a data problem nobody wants to own — I would like to hear about it.

I reply to everything within 24 hours.

Email rcarrascal@gmail.com LinkedIn in/racar GitHub @racar

Timezone

UTC−5 · COT — overlaps EU morning, US morning