Backend Development
I design REST APIs, service architecture, authentication, databases and integrations using NestJS, Spring Boot and Node.js.
Fullstack Developer — Portfolio 2026
I build scalableweb applicationsthat turn ideas intoreal products.
I'm Agustín Hernández Serpa, a Fullstack Developer specialised in backend and application architecture. I build modern platforms with NestJS, Next.js, React and Spring Boot, integrating third-party services and designing production-ready solutions.
- Fullstack Developer
- Backend & Software Architecture
- Montería, Colombia
- Available for projects
About
I do more than writing code. Igenerate solutionsand solve issues
I care about building software that is reliable, scalable and easy to maintain. Throughout my career I have worked on projects across HealthTech, digital media and customer service platforms, taking part from architecture design through to deployment and production maintenance.
I enjoy solving complex problems, optimising existing systems and turning business requirements into applications that create value for users and companies.
What I do
I build end-to-endsolutions.
Four areas of work that usually come together within the same project, from architecture to production release.
Frontend Development
I build fast, modern and optimised interfaces with React and Next.js, focused on user experience and performance.
Integrations
I connect applications to external services such as Twilio, SendGrid, GoHighLevel and other APIs to automate processes and improve communication between systems.
Deployment & Infrastructure
I set up production environments, deployments and development workflows using tools such as Dokploy and Git to ensure reliable releases.
Experience
Professionalexperience.
01
Fullstack Developer
Axias Media
2025 - Present
I build applications for the healthcare and customer service sectors, implementing features on both the frontend and the backend. I also work on performance optimisation, database migrations and integrations with external services.
02
Lead Fullstack Developer
La Nota Digital
I led the full development of a digital journalism platform, defining the backend architecture, handling the system deployment and guiding the development team technically.
03
Programming Tutor
Unitareas Ibagué
For almost three years I helped university students strengthen their knowledge of programming, algorithms and data structures using Java, Python, PHP, C# and MySQL.
Projects
Products and platformsI've worked on.
Answer Clinic
Voice AI / HealthTech / 24/7 Support
No patient call goes unanswered. AI voice agents that cover the hospital after hours, book appointments and hand the call to a person when the case calls for it.
Role — Fullstack Developer — backend architecture, telephony and voice AI integration, and the operations dashboard.
- NestJS
- Next.js
- Twilio
- ElevenLabs
- PostgreSQL
- Redis
- AWS
- SendGrid
- Gmail API
Axias Media
Digital Marketing / Custom Software
Several applications, one team. Product development for a marketing and content agency in Florida: the internal tools and client platforms that keep their day-to-day running.
Role — Fullstack Developer — product development across several applications, backend, frontend and integrations.
- NestJS
- Next.js
- Spring
- Twilio
- ElevenLabs
- PostgreSQL
- SQL Server
- Prisma
- TypeORM
- Redis
- AWS
- SendGrid
- Gmail API
La Nota Digital
Digital Media / Technical Leadership
A digital newspaper in Montería, Córdoba. I built the platform and also led two developers: assigning work, reviewing code and teaching them the tooling so the newsroom keeps growing without depending on me.
Role — Lead Fullstack Developer — architecture, development and leadership of a two-developer team.
- NestJS
- Next.js
- PostgreSQL
- Redis
- Cloudinary
Acosta Santuario Abogado
Professional Website / Lead Generation
A lawyer's website in Medellín with a single goal: whoever lands on it ends up writing or calling. Clear message, instant load and contact always one click away.
Role — Fullstack Developer — website, contact backend and production rollout.
- Next.js
- NestJS
- PostgreSQL
Technologies
Technologies Iwork with.
01
Frontend
- React
- Next.js
- TypeScript
02
Backend
- NestJS
- Spring Boot
- Node.js
03
Databases
- PostgreSQL
- SQL Server
- MySQL
- MongoDB
- Redis
- Firebase
04
Tools
- Prisma
- TypeORM
- Git
- Dokploy
- Expo
- Electron
How I work
How I approachevery project.
A simple, repeatable method that keeps product quality steady over time, whatever the size of the team.
01
Understand the problem
Before writing a single line of code, I work to understand the business goals and the real needs of the user.
02
Design the solution
I define a clear architecture, prioritising scalability, maintainability and performance.
03
Build with quality
I write clean, reusable and maintainable code, following good practices and agile methodologies.
04
Improve continuously
I analyse how the system behaves, optimise processes and keep a mindset of constant learning.
Achievements
A fewresults.
Work delivered within real teams and products, from the first release through to production maintenance.
- 01
Development of platforms running in production.
- 02
Technical leadership of development teams.
- 03
Implementation of scalable backend architectures.
- 04
Integration of multiple external services for automation.
- 05
Performance optimisation and maintenance of existing applications.
- 06
Technical training for new developers and students.
Philosophy
My approach.
I believe the best software is not the one with the most features, but the one that solves problems in a simple, reliable and sustainable way.
That is why I aim to build applications that can grow over time, keeping a solid architecture and a quality user experience.
Contact
Have a projectin mind?
I am always interested in new challenges, collaborations and opportunities to build products that make an impact.
If you are looking for a Fullstack Developer experienced in backend architecture, modern web development and service integrations, I would be glad to talk.