Available for new projects

Marlon Coreas · Independent product designer & developer

More useful inquiries.Less manual work.

I plan, design and build bilingual websites and custom software for service businesses. Before promising an outcome, we define the problem, the scope, the timeline and what success should look like.

See the evidence Tell me the problem

How it works online

From idea to live

01 · plangoals before pixels

02 · buildfast, clear, yours

03 · launchlive and supported

Working principle

Scope, price and ownership agreed first

13.69°NDEV/26

Publicly verifiable

03working products online

APP STOREone product published

EN / ESdelivered bilingually

Selected work

Proof, not promises.

Three public projects you can open and use, plus the one I'm building now. Each finished project shows the problem, the work delivered and the evidence that can be checked today.

Peek Compress displaying the contents of an archive on macOS

My own product · Mac app on the App Store

Peek Compress

A Mac app that lets people open, browse, edit and compare compressed files without unpacking anything or filling their desktop with folders. I designed it, built it, published it and wrote the site that sells it.

Product · Design · Development · Launch site

Challenge: Make archive work faster without creating temporary folders or changing a familiar Mac workflow.
Delivered: Native product experience, visual system, App Store release and its commercial website.
Evidence: Available publicly on the Mac App Store and its product site.

View live project App Store

Client work · Bilingual service-business website

NC Home Remodeling

A bilingual website that presents completed remodeling work, explains the services clearly and gives homeowners direct paths to call or request a quote.

Strategy · Design · Development · Google visibility

Challenge: Turn a collection of finished projects into a credible sales presence for homeowners in the greater DC area.
Delivered: Positioning, bilingual content, project presentation, responsive build and search-ready technical foundations.
Evidence: The complete bilingual website and its quote paths are public. Lead-volume claims are intentionally omitted until client data is authorized.

View live project

My own product · Free bilingual web tool

LoanPilot

Seven free calculators for the money questions most Salvadorans have to take on trust: what a loan or a card paid at the minimum will really cost, what a severance settlement and a Christmas bonus should pay, how overtime is counted, and what payroll withholdings and the year-end tax balance come to. Built on the labor code and official rate tables, reconciled against the labor ministry's own settlement calculation, and nothing anyone types ever leaves their browser.

Idea · Design · Development · Launch

Challenge: Turn scattered legal and financial rules into answers a person can trust, without requiring expertise, an account or any personal data.
Delivered: Calculators for loans, credit cards, severance, the Christmas bonus, overtime, payroll withholdings and the annual tax balance; yearly cost breakdowns, extra-payment scenarios, PDF and Excel export of the loan schedule, and shareable links that carry the figures.
Evidence: Free to open and test in Spanish or English; every official source is cited and dated on the page, the settlement figures are reconciled against the ministry's own calculation, the rule registry and the code are public on GitHub, and calculations remain in the browser.
Judgment: Salvadoran law does not always say one thing. Where a text and the ministry's own practice disagree, the site publishes both readings, says which one it applies and marks it as applied — never as correct. Read the disputed rules

View live project

My own product · Not announced yet

Next product

A product of my own currently in build and test. There is nothing to open or verify here yet, and that is the point: this card is what an honest work-in-progress looks like next to three finished projects.

Idea · Design · Development

Challenge: Still being sharpened against real use before anything is announced.
Delivered: In progress — research, prototypes and the first version that has to survive daily use.
Evidence: None yet, deliberately. It gets a link and the same problem, work and evidence breakdown as the projects above on the day it ships.

What I can do for you

Choose the problem, not a list of technologies.

These are the three situations where I can be most useful. Every engagement begins with a written scope, timeline and price before development starts.

A website that earns trust

For service businesses whose current site is unclear, dated or difficult to find. The work starts with what a customer must understand before making contact.

Best fit: established service businesses with real work, a clear offer and someone ready to answer inquiries.

From US$2,000

Positioning and content
English & Spanish
Mobile, accessibility and search foundations

Explore business websites

Custom software

Web platforms, client portals, quoting and booking systems, internal dashboards, integrations between the tools you already pay for — software shaped around how your business actually runs.

Best fit: a repeated process is costing time, creating errors or forcing the team to work across disconnected tools.

From US$8,000

Process discovery
A focused first release
Support after launch

Explore custom software

Products built from scratch

For founders who need to turn a specific, testable idea into a first useful release — including web and desktop software.

Best fit: the user, problem and first essential workflow can be described without relying on a long feature list.

From US$10,000

Research and product scope
Desktop and web
Launch and App Store experience

See the product process

How I work

Small details. Serious outcomes.

Good software is not just working software. It explains itself in seconds, feels considered at every edge, and is still easy to change a year later.

01
Fit before proposal
A short conversation confirms the problem, decision maker, constraints and whether I am the right person to help.
02
Written scope before work
You receive the deliverables, exclusions, schedule and fixed price or billing model before committing.
03
Visible progress
You talk directly with me, review working increments and make decisions while changes are still inexpensive.
04
Launch with ownership
Access, documentation and next steps are handed over clearly. Support is agreed, never assumed.

About

A technical partner, not another vendor.

I'm Marlon Coreas, an independent designer and developer based in El Salvador. I've taken my own products from an empty file to the Mac App Store and I work directly with businesses in the US and Latin America. There is no handoff to an anonymous delivery team: the person in the first conversation is the person responsible for the work.

Taking on new client projects — working remotely with businesses across the US and Latin America.

Capabilities

Business websites
Web platforms and portals
Custom web applications
Online stores
Booking and quoting systems
Internal dashboards and tools
Automation and integrations
Desktop apps
English and Spanish
Google visibility
Ongoing support and evolution

GitHub LinkedIn

A useful filter

A good project fit is clear on both sides.

Usually a good fit

There is a real business or user problem to solve
A decision maker can review progress and answer questions
Quality and maintainability matter more than the cheapest possible build
The first release can be focused around an essential outcome

Probably not a fit

Guaranteed rankings, sales or growth without evidence
Copying another product without understanding the users
An undefined feature list with a fixed deadline and no discovery
Speculative work in exchange for future exposure or revenue share

Before we talk

Straight answers to common questions.

How much does a project cost?

It depends on the scope and risk. After an initial conversation, you receive a written proposal with deliverables, exclusions, schedule and price. The inquiry form asks for a budget range so I can recommend a realistic path.

How long will it take?

A focused business website and a custom platform are different projects. I confirm the schedule only after understanding the content, integrations, feedback process and launch requirements.

Do you guarantee more leads or Google rankings?

No. I can build the message, user journey, performance and search foundations needed to compete, then measure what happens. No responsible developer can guarantee market behavior or rankings.

Who owns the finished work?

Ownership, accounts, licenses and handover are written into the proposal. You receive the agreed access and assets when the project obligations are complete.

What happens after launch?

Every project includes a defined launch and handover. Ongoing support, maintenance or a next release can be agreed separately when it is useful.

Have a project in mind?

Tell me the problem. I'll tell you honestly if I can help.

Share the context, desired outcome, timing and a comfortable investment range. I will reply personally with the next useful step — even when that means recommending a smaller solution or a different specialist.