Arvin Arun Dcosta (home)

Open to full-stack roles, internships & freelance work

Full-Stack Developer · Final-year CSE @ VIT-AP

I build full-stack web apps end to end — and add AI where it actually helps.

From the UI and the API to the database and the deployment. Typed end to end, tested against real databases, and measured before I make claims.

01 Selected work

Live projects, with the numbers to back them.

Each one is deployed, open source and written up. The figures come from the projects' own tests and evaluations, caveats included.

Fig. 01 AI / ML Live

SynChat

A messenger whose group chats sort themselves into topics as each message arrives, with no threads to start.

of messages in the right lane with the AI tidy-up
86% (how this was measured)
median time for a topic to reach other members’ screens
136 ms (how this was measured)
backend tests against a real PostgreSQL
245
  • React
  • TypeScript
  • Vite
  • Tailwind CSS
  • Zustand
  • Node.js
  • Express
  • +13 more

Fig. 02 Web App Live

SkillSwap

A peer-to-peer skill exchange: get matched with someone who can teach what you want to learn, agree a plan, and meet in a live learning room.

unit and integration tests
200+ (how this was measured)
WCAG 2.2 checks on every page, in CI
AA (how this was measured)
signals behind every match score
5 (how this was measured)
  • React
  • TypeScript
  • Vite
  • Tailwind CSS
  • TanStack Query
  • React Router
  • CodeMirror
  • +14 more

Fig. 03 Web App Live

SafetyWatch

Community crime reporting: file a report with or without an account, follow it with a tracking ID, and explore verified incidents on a list, a map and charts.

accounts needed to file or track a report
0
steps from incident to submitted report
3
review states, from pending to resolved
5
  • Next.js
  • React
  • TypeScript
  • Tailwind CSS
  • Radix UI
  • React Hook Form
  • Zod
  • +9 more

All 3 projects in one place, filterable by category and tech.

Browse all projects

02 About

Hi, I’m Arvin.

I’m a final-year Computer Science student at VIT-AP who builds full-stack web apps end to end: the UI, the API, the database and the deployment.

Lately most of my time goes into bringing AI into the web: semantic search, embeddings running on my own server, and LLM features that stay optional, get validated and fail gracefully.

I like shipping things I can measure. Every number I quote comes with its caveat, and the known failures get tests too.

How I build

  • 01

    AI that earns its place

    Semantic search with pgvector, small models running locally, and opt-in LLM features whose output is validated in code.

  • 02

    Realtime that survives bad networks

    WebSockets with idempotent retries, offline queues and reconnect catch-up.

  • 03

    Security from day one

    Server-owned roles, session checks on every mutation, rate limiting and schema-validated input.

  • 04

    Typed and tested end to end

    TypeScript and Zod from database to UI, with Vitest and Playwright running against a real Postgres.

  • 05

    Honest numbers

    Benchmarks with their caveats, baselines to compare against, and dead ends written down.

  • Motto

    Measure it. Test it. Write down where it falls short.

03 Skills

The stack I build with.

Grouped by layer. The count next to a skill is how many of the projects on this site use it; select it to see them.

Languages

  • TypeScript
  • JavaScript
  • Python
  • Java
  • HTML
  • CSS

04 Services

Need something built? I can help.

For founders, small businesses and teams who need a fast, reliable web product. Every project starts with a clear scope and a fixed quote.

  • Landing pages

    A fast, responsive landing page that reads well on phones, loads quickly and is ready for search engines.

    • Responsive layout for phone, tablet and desktop
    • Contact form or email sign-up
    • SEO basics: titles, meta tags, sitemap, link previews
    • Deployed to your domain

    Pricing Custom quote

    Get a quote : Landing pages
  • Full-stack web apps

    A complete web application, with sign-in, a database, dashboards and APIs, built with React or Next.js, Node.js and PostgreSQL or MongoDB.

    • Authentication and user roles
    • Database design and REST or realtime APIs
    • Admin dashboard
    • Automated tests and deployment
  • AI features for your app

    Useful AI added to an existing product: search by meaning, drafting from photos or text, summaries. Output is validated, and there is a fallback for when the model fails.

    • Semantic search with embeddings
    • LLM features with structured, validated output
    • Gemini, Claude or models on your own server
    • Costs and privacy kept in check
  • Redesign & migration

    A modern, faster version of your current site, or a move to a better stack, without losing your content.

    • Modern responsive redesign
    • Migration to Next.js, Astro or React
    • Performance and accessibility fixes
    • Existing URLs and SEO preserved
  • Bug fixes & improvements

    A broken page, a slow query, a failing deploy or a feature that needs finishing, diagnosed and fixed in your existing code.

    • Bug diagnosis and fixes
    • Performance improvements
    • New features in your existing code
    • A short write-up of what changed

Not sure which fits? Describe your project and I'll suggest the simplest option.

05 Process

How we'll work together.

A clear, predictable process from the first message to launch, and after.

  1. 01

    Discovery

    We talk through your goals, your users, the must-haves and the deadline.

    You get A written scope and a fixed quote

  2. 02

    Design

    Wireframes or a mockup of the key screens, so we agree on the look and flow before any code is written.

    You get Approved layouts

  3. 03

    Build

    Development in small milestones, with regular updates and a preview link you can click through.

    You get A working preview

  4. 04

    Deliver

    Deployment to your hosting and domain, a walkthrough of how everything works, and the full source code.

    You get A live site you own

  5. 05

    Support

    Bug fixes after launch, and optional ongoing maintenance as your product grows.

    You get Peace of mind

06 Background

Education.

Education

  1. B.Tech, Computer Science and Engineering

    Final year

    VIT-AP University

    2023 – 2027

07 Contact

Let’s build something good.

Hiring for a full-stack role or an internship, or need a web app built? Send me a message and I’ll get back to you.

Download résumé

The quickest way to reach me is email.

Tell me about the role or the project, and I'll reply from arvindcosta200@gmail.com.

Email me