software engineer — london

Building AI products, and the infrastructure that keeps them fast.

Nearly five years across web platforms, cloud infrastructure, and AI systems — currently shipping RAG and AI-agent workflows on SJR's GX Manager.

  • first-client launch
  • rag & agent workflows
  • image processing with microsoft

who i am

About me

Marcus Dantas profile picture

I am a London-based Software Engineer with nearly five years of experience building web applications, internal tools, cloud-native systems, and AI-enabled product features across startup, consultancy, and research environments.

Since May 2025 I have worked across SJR's GX Manager stack, modernising infrastructure, improving question latency from roughly 25 seconds to 8 seconds, supporting the product's first-client launch, and developing advanced image-processing features in collaboration with Microsoft.

My broader work spans Python, JavaScript, Vue, Go, Kubernetes, Docker, Terraform, AWS, and Azure AD B2C. I am especially interested in reliable software delivery, developer tooling, pragmatic automation, RAG systems, and AI-agent workflows.

View my resume

experience — sjr, 2025 onwards

The GX Manager story

  1. the product

    AI answers for enterprise conversion

    GX Manager builds dynamic conversion experiences on RAG and AI-agent workflows. When I joined SJR, answering a single question took around 25 seconds — too slow for the product to feel alive.

    25squestion latency at the start

  2. the work

    Modernise the infrastructure underneath

    I modernised the platform infrastructure end to end — application code, delivery, and the path a question takes through the stack — cutting per-question latency to roughly 8 seconds.

    8squestion latency after the work

  3. the proof

    First client, live

    The product launched with its first client, and I built advanced image-processing features in collaboration with Microsoft along the way.

    1stclient launch supported

personal projects

What I'm building

live demo

Banking dashboard

A personal-finance dashboard fed by real account data over UK Open Banking (TrueLayer), with monthly budget vs actual, balance trends, recurring outgoings, and a privacy mode for screen-sharing.

  • Nightly Open Banking sync into the same dashboard the demo shows
  • Public demo runs entirely on synthetic data from a seeded RNG
  • Python
  • Streamlit
  • TrueLayer
  • SQLite
  • GitHub Actions

The demo sleeps after ~12 idle hours — one click and about 30 seconds wakes it.

private repo

Flight price tracker

An aggregator that watches London to Fortaleza fares across airlines using advanced scraping and multiple APIs, with pattern recognition to flag genuinely cheap fares rather than noisy price drops.

  • Scheduled checks log fares by category into a live dashboard
  • All-time-low tracking and good-price flags per route shape
  • Python
  • Streamlit
  • Turso
  • Plotly
  • Scraping APIs

in progress

Job search tool

An aggregation and tracking tool for the job hunt — currently being built. Notes and a demo will land here once it is ready to show.

in progress

AI second brain

A personal knowledge base that ingests my notes, docs, and bookmarks into a local RAG system I can query in natural language. Early days — write-ups will follow as it takes shape.

archive — where i started

Earlier projects

Adrastos

Initiated and led the development of a social media platform that is architected around the connection of people through videogames.

Small MVP project where I had the opportunity to heavily contribute to the front end and part of the back end, developed using Ruby on Rails 6.

  • Ruby on Rails 6
  • JavaScript
  • PostgreSQL
  • Heroku
Adrastos

Gamehub

A marketplace for videogames that was rapidly developed by myself and a small team in just a few days.

  • Ruby on Rails
  • JavaScript
  • PostgreSQL
  • Heroku
Gamehub

Mrs Cocktail

A short project that showcases cocktails and allows the user to edit and create their own.

  • Ruby on Rails
  • JavaScript
  • PostgreSQL
  • Heroku
Mrs Cocktail

notes & write-ups

Latest writing

All writing

say hello

Contact

Questions? Get in touch!

If the form is unavailable, email me directly.