Services
Backends, automation, and teaching.
Two kinds of work. Systems built and operated for companies, and one-to-one teaching in programming, mathematics and physics. Both are things I do; neither is a side effect of the other.
Engineering
Scoped, built, deployed and handed over.
Backend and infrastructure
Asynchronous FastAPI services on PostgreSQL, containerised with Docker and supervised by systemd, behind Caddy with automatic TLS. Deployed to hardware you own rather than a platform you rent, and handed over with the documentation needed to run it without me. This is the work I do every day.
- FastAPI
- PostgreSQL
- Docker
- systemd
- Caddy
- Debian
Direct, or through Apollyon for larger builds
Automation and integrations
Workflows that connect a CRM, a database, email and messaging and then run without anyone watching. Where a system has no API, Selenium reads the interface built for people. Cleaning and analysis in Pandas. Built to fail loudly rather than quietly return nothing.
- n8n
- Selenium
- Pandas
- Python
Contracted directly with me
AI assistants and retrieval
Retrieval over your own documents, so answers cite something real instead of being invented. WhatsApp assistants on the channel your customers already use. Local models where the data cannot leave your infrastructure. Bounded to what the underlying API already permits.
- RAG
- OpenAI API
- Local LLMs
Direct, or through Apollyon for larger builds
CRMs, dashboards and web apps
Lead management, conversion funnels and live operational metrics, on a data model designed for the questions you actually ask. Interfaces are scoped and assembled with AI tooling; the API, schema and deployment underneath them are built the usual way.
- FastAPI
- PostgreSQL
- Dashboards
- WebSockets
Delivered through Apollyon S.A.S
How it works
- DiscoveryYour bottleneck and existing stack, then a scope
- BuildIterative, reviewable, tested
- HandoverDocumented, on infrastructure you own
Websites
A site for your business, and someone to keep it online.
A site for your business, designed, built and then actually kept online. Fast, accessible, works on a phone, and findable — a static build behind a reverse proxy with automatic TLS, on infrastructure I run. The design is scoped and assembled with AI tooling; the build, the hosting and the uptime are mine.
- Static build
- Caddy
- TLS
- Debian
Design and build
From$100per project
Hosting and upkeep
From$10per month
Built and hosted by me
- gsalud.co
A dental and facial aesthetics clinic in Bogotá. Designed, built and hosted by me.
- apollyon.lat
The company site for Apollyon S.A.S, bilingual, on the same hosting.
Classes
Programming, mathematics and physics.
I have taught privately alongside my degree for most of my time at university, so this is not a sideline I picked up recently. Remote, in Spanish or English. I read physics at Universidad de los Andes, and the numerical methods coursework behind these subjects is public on my GitHub, so you can see how I work through a problem before booking anything.
- Subjects
- Programming
- Python
- Mathematics
- Physics
- Numerical methods
- Formats
One to one
Remote, by video call. The session goes wherever you are actually stuck.
From$15per hour
Small group
Up to ten people, remote. One rate for the session however many of you there are, so a study group before an exam works out far cheaper each.
From$40per hour, up to ten people
- Who I teach
University students
Calculus, computational physics, numerical methods. The same coursework I did at Universidad de los Andes and left public.
School students
Secondary mathematics and physics, and a first real programming language.
Working developers
Python and backend depth: async, schema design, authentication, getting it deployed and keeping it up.
Career changers
Coming into programming from another field, with structured teaching rather than a playlist of videos.
Who you would be contracting with
I am COO of Apollyon S.A.S in Bogotá, and larger builds run through the company: a team, a contract, and continuity if I am not the one holding it. Smaller engagements and all teaching are direct with me. Each service above says which applies, and I will tell you plainly if a project belongs on the other side of that line.
Have something worth building?
Tell me what you are trying to build, automate or untangle. I will come back with an architecture and a realistic timeline, not a brochure.