Marcell Kristianto
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Marcell Hermawan Kristianto

AI Engineer & Data Scientist

Intern candidate · Data Science at Binus. I build AI systems, then measure them against a baseline.

Available now · East Jakarta Resume (PDF) ↓

Marcell Hermawan Kristianto in his Binus Data Science Club 26/27 jacket, holding a book
Data Science Club 26/27 · club jacket

Roles I am applying for

No. 01 · Lead

AI Engineer

Fine-tuned CLIP, hybrid retrieval and an AI sales copilot, all in production.

Proof: Toko Marcell

No. 02

Data Scientist

Every retention strategy costed in dollars; the model spends 18% less than discounting everyone.

Proof: Telco churn

The folio

Two pieces of work you can open

  1. I. Toko Marcell search · live
  2. II. Telco churn model · notebook

I · The shop

toko-marcell.vercel.app/?q=black+leather+boots Toko Marcell search results: 118 results for black leather boots
Copilot The sales copilot chat: a shopper asks in Indonesian and the copilot recommends products
Captured from the live site, 29 Sep 2026: hybrid search, then the sales copilot answering a shopper.

Recall@126.5%39.2%539 held-out pairs · vs. baseline CLIP

Live

Toko Marcell

A storefront built as a test bench for retrieval.

I fine-tuned CLIP on 5,378 fashion image–text pairs and fused it with BM25 and dense text search in pgvector using reciprocal rank fusion. On top sits a LangChain copilot that works as the shop's salesperson: it finds products for a shopper, recommends and sells them, and answers sizing and store-policy questions.

  • PyTorch
  • CLIP
  • pgvector
  • FastAPI
  • LangChain
  • Next.js

Backend sleeps on a free tier; the first search can take ~40 s.

II · The till

Bar chart of one month of lost revenue on 986 held-out customers: offer nobody $19,654, offer everyone $6,439, gradient boosting at 0.50 $6,244, month-to-month rule $5,538, logistic regression at 0.06 $5,259, gradient boosting at 0.09 $5,226
From the notebook: one month of lost revenue on 986 held-out customers, for each targeting strategy.

Cost / month$6,439$5,259986 held-out customers · vs. discounting everyone

Notebook · reproducible

Telco churn

Who should get the retention discount?

I costed six targeting strategies on the same held-out customers. Logistic regression with a threshold chosen by cost instead of the default 0.5 spends 18% less than discounting everyone. A one-line contract rule gets most of that gain, and the notebook says so, along with the offer success rate below which the model stops winning.

  • scikit-learn
  • imbalanced-learn
  • XGBoost
  • LightGBM
  • pandas

The press

Published research

The ledger

Chapter in press 2nd of 5 authors

ICOBAR 2025

Which CNN should run on a low-power microscope?

We compared six pretrained CNNs on microscope images of toxigenic cyanobacteria. EfficientNetB1 reached 96.72% test accuracy, and FP16 post-training quantization halved its size with no accuracy lost. The work was done with the BDSRC research lab and accepted at ICOBAR 2025.

  • TensorFlow
  • Keras
  • TFLite FP16
  • Transfer learning

The jacket

Patches earned on real work

Each patch names where I used it.

Models & evaluation

  • PyTorch · CLIPfine-tuned image–text retrieval
  • CLIP · VLMsimage–text search
  • TensorFlow · Keras6-CNN benchmark, FP16
  • scikit-learn · XGBoostchurn models, cost-chosen thresholds
  • EvaluationRecall@k · MRR · PR-AUC

LLM & agents

  • LangChain · Geminisales copilot, tool calling
  • NVIDIA NIM · RAGLLM app workshop, 9 h
  • ONNX Runtimecross-encoder reranker
  • Hermes · Pi Agentdaily since Apr 2026

Data & serving

  • PostgreSQL · pgvectorHNSW + BM25 fusion
  • FastAPImodel serving
  • PySpark · Airflowbatch jobs, scheduling
  • Docker · Linuxcompose stacks
  • Next.js · Supabasestorefront, team portal
  • Python · R · SQLR for Bayesian stats

The campus walk

How I got here

Five stops since my first semester, and where I am now.

  1. Binus University

    Began a B.Sc. in Data Science. GPA 3.85 / 4.00.

  2. Research Activist

    Binus Data Science Club, with the BDSRC lab. Output: an ICOBAR 2025 paper, in press with Springer Nature.

    Read the paper ↓
  3. PIC, Data Seeker

    Lead 15 delegates in 5 squads, picked through a Kaggle entrance test I set and judged. Built the portal that runs the team's claims and solution vault.

    The team's portal ↗
  4. Mentor Scholarship

    SASC Binus, on a merit grant. Junior mentor, promoted to senior in Aug 2026. Weekly tutoring with study modules I design.

  5. TA · NVIDIA DLI workshop

    Teaching assistant for NVIDIA's 9-hour Rapid Application Development with LLMs workshop at Binus: poster, venue, registration, screening, and helping participants debug their labs.

    The club's post ↗
  6. 5th semester

    Looking for an AI Engineer or Data Scientist internship.

    Email me ↗

The credentials book

Ten certificates, each one checkable

Open one to read it here, or follow it to the issuer.

Contact

Hiring an AI Engineer or Data Scientist intern? Contact me.

marcellkristianto.ai@gmail.com
Chibi Marcell waving, holding a laptop

Verify at the issuer ↗