Santiago Serrano

/01Services

Services.

I work in three kinds of situation. Tell me which one is yours and I'll tell you honestly whether it makes sense to work together.

01

A custom-built system

Your business depends on manual processes or tools that don't talk to each other, and no ready-made product fits what you need.

↳ Ticketing, points of sale, internal systems, clinic platforms

02

Improve or rescue a system that already exists

You already have a platform, but it crashes, it's slow, nobody understands it or it can't keep up as your business grows.

↳ Platform changes, speed, tidying up the code

03

Ongoing support on a monthly plan

You want someone to take care of your platform (development, servers and support) without hiring a full team.

↳ Constant improvements, servers, support and evolution

/Services

I can help you build and improve digital systems for your business.

01

Platforms to run operations

I build internal systems so companies can manage from one place processes such as orders, inventory, customers, payments, refunds, records, reports and user administration.

I also set up access levels so each person sees and edits only the information that corresponds to them.

Frequent technologies

  • Next.js
  • NestJS
  • PostgreSQL
02

Payments and connections to other services

I connect platforms with external services to automate sales and communication: Stripe, Mercado Pago, SPEI, Shopify, WhatsApp Business and automated email.

I also set up mechanisms to detect duplicate payments, communication errors or transactions that need review.

Frequent technologies

  • Stripe
  • Mercado Pago
  • Shopify
  • WhatsApp Business
03

Data and artificial intelligence

I design the structure a company needs to organise and make use of its information.

That can include bringing together data from different platforms, automating reports, analysing results and using artificial intelligence to help interpret information that has already been validated.

Frequent technologies

  • Python
  • Claude API
  • scikit-learn
04

Infrastructure and stability

I also work on the part users normally don't see, but that keeps a platform running.

It includes servers, automations, backups, task processing and systems prepared to recover when an error happens.

Frequent technologies

  • Cloudflare
  • Vercel
  • Azure
  • AWS
  • Docker

/ How we work

What a project with me looks like, from the first conversation to launch.

No surprises: you know what happens at each stage, what you get and when.

2–3 months

from first conversation to production in a typical project

01 / 06 — We talk

  1. 01
    Free

    We talk

    You tell me how your business runs today: what's done by hand, what gets lost, what eats your time. I listen first and propose after.

    You getA clear idea of what's worth building

  2. 02
    Paid

    Proof of concept

    Before committing to the whole project, I build a version that proves the solution works with your real case. You decide with something in hand, not a slide deck.

    You getA working proof and an approved plan

  3. 03
    Document

    Requirements

    Together we write down what the system does, what it doesn't, and how we'll know it's done. It's the project's technical agreement.

    You getRequirements document (SRS)

  4. 04
    Every week

    Built in the open

    I work with a Kanban board you can see and a delivery calendar. Every step is tested in a real environment, not in screenshots.

    You getProgress you can use and review

  5. 05
    Launch

    I take you to production

    Domain, servers, real payments, migrated data and support on launch day. The project ends when your team is already using it.

    You getYour system running with real customers

  6. 06
    Optional

    Maintenance

    A monthly plan for improvements, servers and support. The code, accounts and access are yours from day one.

    You getA system that keeps growing with you

/How I work

Five principles I apply in the projects I build.

It isn't only about a system working. It also has to be secure, reliable, easy to maintain and ready for unexpected situations.

  1. Principle 01

    Important calculations are verified on the server

    Prices, payments and important quantities don't depend only on what the user's screen shows.

    The system checks these data again before saving an operation, reducing errors and tampering.

    ↳ Applied in: VIP Cleaners POS · MyTicket MX

  2. Principle 02

    A payment or a notification can arrive more than once

    Payment services and other external platforms can send the same information several times or deliver it late.

    I design systems to recognise these situations and avoid duplicate charges, records or actions.

    ↳ Applied in: MyTicket MX · Elements Method

  3. Principle 03

    I test real situations, not just the ideal scenario

    A system can work with one person and fail when hundreds do something at the same time.

    That's why I run tests that simulate situations like two customers trying to buy the same seat. MyTicket has more than 3,000 automated tests, including specific ones to prevent duplicate seat sales.

    ↳ Applied in: MyTicket MX

  4. Principle 04

    I document decisions and the real state of the project

    I keep a record of the important decisions, pending items and limitations of each system.

    If something still depends on a client decision or needs improvement, it is documented as pending rather than presented as finished. That way other people can understand and continue the project.

  5. Principle 05

    I use artificial intelligence as a tool, not as a substitute for review

    I use artificial-intelligence tools to speed up programming, testing and review tasks.

    I split the work into roles (architecture, development, testing, review and security) and verify the result before integrating it. AI helps me work faster; the final decisions and the review remain my responsibility.

    ↳ Applied in: MyTicket MX

/ How I charge

By stages, with deliveries you can try out, or with a monthly fee that includes development, servers and support.

/ Always included

The code and the accounts are in the client's name. Repository, servers, domains and access are yours from day one.

/ What I don't do

  • — Template sites
  • — WordPress maintenance
  • — Projects without a defined scope
Tell me about your project