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Grow without your website becoming the bottleneck.Web Platform Engineering

Building fast, secure, and scalable web platforms that hold up as traffic, teams, and features grow.

Understanding the discipline

What a web platform really is.

A web platform is the system a business runs its public face on — the pages customers see, the services behind them, and the process by which anything on it changes. It is infrastructure, not a brochure.

The distinction matters commercially. A brochure is finished when it launches. A platform is judged by how cheaply it can be changed for the next three years, because that is where almost all of its cost lives.

  • A website used to be a launch. It is now a system that changes weekly.

  • Speed stopped being a technical metric and became a revenue one.

  • Publishing moved from engineering to the teams who own the message.

  • The real cost is not the build. It is every change after it.

Fast as a budget, not a hope

Performance targets set as numbers and enforced while the site is being built, so speed doesn't decay the first time someone adds a script.

Editable without a ticket

A content model shaped around how your team actually writes, so publishing stops routing through engineering.

Built to be handed over

Typed, component-driven architecture, documented and transferred — so your developers can take it forward without us.

The business case

Why businesses invest in web platform engineering.

Returns that show up on the business, not on the engineering backlog.

  • 01

    Speed that shows up in revenue

    Faster pages hold visitors and lift search rankings, and the gain is measured rather than assumed — a budget with a number on it, not a hope.

  • 02

    Change scoped in days, not rebuilds

    A clean architecture makes the blast radius of any change obvious, so a request comes back with a scope instead of a quote for starting again.

  • 03

    Publishing without engineering

    Marketing ships a page on Tuesday and a developer never sees it, because the content model was shaped around how the team actually writes.

  • 04

    One rebuild, not another migration

    A platform your own team extends, so the next three years are additions to what exists rather than a second re-platforming project.

What we build & capabilities

The things you can commission — and what each one ships with.

Defined engagements, one at a time: the thing itself on screen, and the capabilities that come with it.

01 / 06

Front-end architecture

A typed, component-driven front end where shared interface is built once and every page inherits it — so the next feature is an addition rather than a negotiation with the last one.

Capabilities

  • Design system
  • Reusable components
  • Typed codebase
  • Per-breakpoint layouts
  • Documented handover

Business outcomes

Where the business is today, and what changes.

The operational difference, in the terms the business already measures itself in.

Every change comes back quoted as a rebuild, because nobody can predict what it will break.
Changes get scoped in days, because the architecture makes the blast radius obvious.
Marketing files a ticket to change a headline, then waits for the next release.
Marketing publishes it, and engineering never sees it.
The site is slow, and the cause is somewhere between the images, the CDN, and the code.
Performance has a budget, an owner, and a number that fails the build when it slips.
The platform was already re-bought once, and it's the constraint again.
The platform is one your own team extends — so the next three years are additions, not another migration.

Faster load and better SEO

Scales without re-platforming

Lower maintenance cost

Our engineering process

How the engagement actually runs.

Every stage has an owner, an output, and a point where you can change direction.

  1. 01

    Discovery

    What the platform has to change commercially, and where the current one actually hurts.

  2. 02

    Architecture

    The rendering strategy, component model, and stack chosen for year three, not only launch.

  3. 03

    Content modelling

    The CMS shaped around how the team writes, so publishing never routes back through engineering.

  4. 04

    Design system

    Shared interface built once, per breakpoint, and reviewed on real devices.

  5. 05

    Build

    Short, reviewable increments against a performance budget that fails the build when it slips.

  6. 06

    Quality & accessibility

    Automated tests and WCAG checks run through delivery, not bolted on at the end.

  7. 07

    Deployment

    Edge delivery, CI/CD, and a rollback path rehearsed before the first real release.

  8. 08

    Handover & iteration

    Documented, transferred to your team, and improved by the people who built it.

Why Sumago

Why teams choose Sumago.

The technology partner serious businesses build with — and stay with.

Performance as a gateCertified engineeringBuilt to hand overAccessible by defaultScales without re-platforming

Business understanding first

We understand the business before writing a line of code.

Strategic consulting

A consultative partner, not just a development shop.

Multidisciplinary team

Analysts, architects, designers, engineers, cloud & AI specialists, QA.

Transparency

Clear communication in every engagement.

Engineering quality

High standards, scalable and secure architecture.

Long-term partnership

Support and improvement long after delivery.

Technology ecosystem

Mainstream technology, chosen so you can hire for it later.

The stack is a means, not a position. It gets chosen against your constraints — and it stays maintainable by people who aren't us.

Next.js / ReactTypeScriptHeadless CMSEdge / CDN
  • Slack

Proof of work

Work that has already shipped.

Real engagements, named clients, and what changed for the business behind them.

An Aggregator Platform for a Fragmented, High-Value Market
Retail & E-commerce

An Aggregator Platform for a Fragmented, High-Value Market

Client challenge
A vast, high-value trade was running without a home. Buyers had no reliable way to discover genuine inventory or compare it with confidence; sellers had no efficient way to reach a wider audience; and with no trusted intermediary in the middle, every transaction carried friction and risk. The value was undeniable — but it was scattered across countless disconnected sellers, invisible to the buyers who wanted it. The opportunity was not a better listing site; it was to organize an entire market.
Our solution
A B2B2C aggregator platform that brings both sides of the trade onto one trusted marketplace. Sellers gain reach and a professional storefront through a subscription that scales with their ambition; buyers gain effortless discovery, confident comparison, and a direct line to verified sellers; and the platform operator governs quality and trust across the whole ecosystem — verifying participants, curating what appears, and keeping the marketplace credible as it grows. Two purpose-built experiences, one connected network. ### The platform A three-part ecosystem on one shared backend, each surface built for a different user: - **Buyer App (Android & iOS)** — *for the consumer.* A simple, mobile-first way to discover inventory, compare with confidence, and connect directly with verified sellers. *How it helped:* removed the friction and doubt that kept buyers away, drawing demand onto the platform and giving the marketplace its pull. - **Seller App (Android & iOS)** — *for the dealer.* A self-serve storefront to list inventory, manage listings, respond to interest, and track demand — all from a phone. *How it helped:* gave sellers real reach and control, attracting the supply that makes the marketplace worth visiting and driving the recurring subscription revenue. - **Web Operations Platform** — *for the operator.* The command layer to verify participants, curate listings, run the subscription model, and govern trust across the whole market. *How it helped:* kept the marketplace credible and commercially healthy as it scaled — the trust engine that lets both sides transact safely. ### Architecture highlights - **API-first, shared-backend architecture** — two mobile apps and the operator platform are served by one consistent API, so every surface stays in sync. - **Discovery-optimized data layer** — catalog modeling and indexing tuned to keep search and comparison fast as listings scale into the thousands. - **Horizontally scalable and cache-backed** — stateless services plus caching and a CDN for media keep the experience fast under load. - **Decoupled monetization layer** — subscription and payment logic is isolated from the marketplace core, so commercial rules can evolve without risk. - **Secure, token-based auth** — frictionless OTP onboarding with JWT-secured sessions across every app. ### Technology stack The buyer and seller apps are built as **cross-platform React Native** mobile applications — one build that runs natively on **both Android and iOS** — while the operator platform and backend run on the **MERN stack** (MongoDB · Express.js · React · Node.js).
Business impact
The platform converts a fragmented, informal trade into an organized, trust-driven market with its own gravity: the more sellers list, the more buyers browse, and the more each side has a reason to stay. Monetization comes not from one-off fees but from a **recurring-revenue subscription model** that grows with seller success — a business that compounds as the network expands. For the operator, it turns market chaos into a defensible, scalable, and self-reinforcing asset.

Marketplace Architecture · Trust & Verification · Discovery & Search · Subscription Monetization · Operator Governance