Available for select opportunities
Yohanes Sefrianto Laga Keraf
I design and ship data-intensive software — from pipelines and backends to AI-powered automation and the dashboards that make it all legible.
About
I build the systems behind the product — and the dashboards that explain them.
I'm Yohanes, an engineer who works across the full data and software lifecycle — from backend services and data pipelines to AI-powered automation and the business intelligence layer that turns all of it into decisions people can act on.
My work sits at the intersection of five disciplines: software engineering, data engineering, AI engineering, automation, and BI development. I like that intersection — it means I rarely just write code, I design how data flows, gets processed, gets modeled, and eventually gets understood.
I care about correctness, clean architecture, and building things that keep working quietly in the background long after they ship. If I can automate a manual process, integrate an LLM to remove repetitive work, or turn a spreadsheet into a live dashboard — I'm interested.
Focus
Data-intensive software & AI-driven automation
Approach
Ship reliable systems, then make them legible
Currently exploring
Applied LLMs & agentic workflows
Skills
Range across the whole data & software stack.
Frontend
Building fast, accessible interfaces for the tools people actually use.
Backend
APIs and services designed to stay correct under real-world load.
Data Engineering
Pipelines that move data reliably from source to decision.
Cloud
Deploying and running systems on managed infrastructure.
AI
Applying LLMs and ML to real product and business problems.
Automation
Removing manual work with dependable, monitored workflows.
DevOps
Shipping changes safely and often.
Databases
Modeling and tuning storage for correctness and speed.
Business Intelligence
Turning raw data into dashboards decision-makers trust.
Programming Languages
Comfortable moving between languages depending on the job.
Experience
A path through software, data, and AI.
-
Software & Data Engineer
2024 — PresentCompany Name
Building backend services and data pipelines that power internal analytics and customer-facing features.
- Designed and shipped ETL pipelines feeding a BigQuery warehouse used for company-wide reporting
- Built REST APIs and automation workflows that removed hours of manual weekly work
- Introduced CI/CD pipelines that cut deployment time significantly
-
Business Intelligence Developer
2023 — 2024Company Name
Owned the reporting stack end to end — from raw source data to the dashboards leadership relied on daily.
- Modeled data warehouses and built dashboards tracking core business KPIs
- Automated recurring reports with scheduled pipelines and n8n workflows
- Partnered with stakeholders to translate ambiguous questions into reliable metrics
-
AI & Automation Engineer
2022 — 2023Company Name
Explored applied AI and automation to reduce manual, repetitive operational work.
- Integrated LLM APIs (OpenAI, Claude, Gemini) into internal tools
- Built automation workflows connecting disparate internal systems
- Prototyped and shipped an internal RAG-based knowledge assistant
-
Software Engineer
2021 — 2022Company Name
Started my professional path building full-stack web applications.
- Developed features across the stack using PHP/Laravel and JavaScript
- Collaborated in an agile team shipping weekly releases
- Learned to balance shipping speed with maintainable, tested code
Featured Projects
Repositories, sorted by what people starred.
Projects couldn't be loaded at build time. Check back soon, or browse the full list directly on GitHub .
Tech Stack
Tools I reach for daily.
Python 
JavaScript 
TypeScript 
PHP 
Laravel 
Node.js 
Docker 
Git 
GitHub 
BigQuery 
SQL Server 
MySQL 
PostgreSQL 
n8n 
OpenAI 
Claude 
Gemini GitHub Statistics
What the commit history says.
—
Public Repos
—
Followers
—
Following
Contribution Activity
Contact
Have a project, a role, or an idea worth building? Let's talk.
I'm open to freelance work, full-time roles, and interesting collaborations across software, data, and AI.