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Available for projects

01 Mark Sevillano / Software engineer

I build the
backend parts
people rely on.

Backend and integration engineer helping teams connect systems, automate workflows, and build reliable cloud infrastructure.

Talk about a project See selected work
System Blueprint signal mapAn editorial system map connecting an API, queue, worker, event, and external systems.FIELD RECORD 08SIGNAL MAP / 0101API02QUEUE03WORKER04EXTERNAL05EVENTROUTED / ASYNC / OBSERVABLECONNECT THE PARTS
8 years building softwareAvailable for selected freelance projects ↓
AWS SERVERLESSENTERPRISE INTEGRATIONSAPI ARCHITECTURENODE.JSSYSTEM DESIGN

02 Selected work

Selected backend, integration, and product work.

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03 Services

Practical support from architecture through implementation.

01

API & System Integrations

Connect business platforms with reliable APIs, webhooks, and asynchronous workflows.

  • APIs & webhooks
  • Salesforce / LMS / CRM sync
  • Asynchronous middleware
  • Identity & CDP integrations
02

AWS & Serverless Backends

Build observable, cost-aware backends with clear handling for failures and retries.

  • Lambda & API Gateway
  • SQS event processing
  • S3 data flows
  • Secrets Manager
03

Backend Troubleshooting & Architecture

Find the cause of production issues and improve the architecture behind them.

  • Production debugging
  • Architecture reviews
  • API design & reliability
  • Failure investigation
04

Data & Workflow Automation

Automate repetitive operations with dependable data processing and reconciliation.

  • CSV transformation
  • Imports, exports & migrations
  • Reconciliation pipelines
  • Business-process automation

04 Experience

From software development to backend leadership and solution architecture.

From individual features
to connected systems.

  1. 01Software Development
  2. 02Backend Development
  3. 03Enterprise Integrations
  4. 04Lead Backend Engineering
  5. 05Solution Architecture

05 Technical capabilities

The tools and platforms I work with.

Backend

JavaScriptNode.jsNestJSCakePHPGo

Cloud / Infrastructure

AWS LambdaAPI GatewaySQSS3Secrets ManagerTerraform

Data

MySQLOracle DatabaseMongoDB

Enterprise / Integration

Salesforce APIJSForceNetSuite automationREST APIswebhooksasynchronous / event-driven integrations

Frontend

Next.jsReactAlpine.jsVite

06 About

Behind the parts
users never see.

I'm a software engineer with 8 years of experience building APIs, integrations, background processing, and cloud infrastructure.

I enjoy work where several systems have to cooperate reliably: understanding how data moves, where failures happen, and how the architecture can make both easier to manage.

Backend engineering is home base, but I also build complete web products when the project calls for it.

Off the clock / SIDE B

Pokémon
A Pokémon geek. Yes, considerably.
Games
Nintendo Switch 2.
Collecting
Plush toys. There's always room for one more.
Listening
Indie music and new discoveries.
Going
Travelling somewhere new.

Make the complicated
feel considered.

Practical engineering for founders, product teams, and agencies.