AI from scratch

Real domain · Finance & Energy

Projects interviewers respect

Hands-on systems with business metrics, public data, and a deployable demo — not curriculum toys. Pick one flagship; ship milestones as you learn.

Recommendation: choose one primary domain (Finance or Energy) and take it from baseline model → serious evaluation → optional GenAI/docs layer → API. Depth beats two half-finished demos every time.

Start here — FraudWatch Week 1

Locked primary: FraudWatch (then FilingPilot later). Follow these steps in order. Code lives in the repo folder fraudwatch/.

Step 0  Setup venv + pip install -r fraudwatch/requirements.txt
Step 1  Write the problem in 5 lines (who, costs, why accuracy fails)
Step 2  Run:  cd fraudwatch && python 01_baseline.py
Step 3  Read PR-AUC table + artifacts/pr_curve_week1.png
Step 4  Build-log note: which model wins and why
Step 5  Drill: precision vs recall for fraud queues

Full walkthrough: fraudwatch/README.md. First script: 01_baseline.py.

Week-1 teaching moment: logistic gets high recall but terrible precision at 0.5; random forest wins on PR-AUC (~0.81 vs ~0.72). Accuracy looks “amazing” for both because fraud is ~0.17% of rows — that is the trap.

When Step 2 works on your machine, tell me — we’ll add 02_thresholds.py (operating-point / cost matrix) next.

Which domain should you pick?

Want GenAI / LLM interviews?     → Finance docs RAG (+ fraud/credit baseline)
Want MLOps / time-series signal? → Energy load forecasting + anomaly detection
Want classic ML depth?           → Credit risk or fraud (imbalance, thresholds)
Unsure?                          → Start with FraudWatch (fast feedback), add FilingPilot later

Default pick if you want the broadest interview story: FraudWatch (tabular ML) → then FilingPilot (RAG over financial documents). Same “risk & trust” narrative, two complementary demos.

Finance flagships

1. FraudWatch — transaction fraud detection Recommended start

Problem: flag fraudulent payments without drowning analysts in false alarms.

Why interviews love it: class imbalance, precision/recall tradeoffs, threshold tuning, feature leakage traps, cost-sensitive decisions — all high-frequency ML interview topics with a clear business story.

Interview line: “I optimised for precision at a fixed recall so the review queue stayed usable — here’s the threshold curve.”

2. CreditRisk — default / risk scoring

Problem: predict probability of default; set an approve/reject threshold.

Slightly more “regulated industry” flavour than fraud — great for fintech / banking roles.

3. FilingPilot — RAG over financial filings / research GenAI signal

Problem: ask questions over 10-Ks, earnings transcripts, or investor PDFs and get answers with citations (no hallucinated numbers).

Interview line: “RAG vs fine-tune: filings change quarterly, so I kept knowledge in the index and versioned the prompt — here’s my eval harness.”

4. MarketSense — light forecasting (optional)

Volatility or direction models on public price data. Use carefully: easy to fool yourself with leakage. Only take this if you can defend time-based splits and walk-forward validation in an interview. Prefer FraudWatch/CreditRisk if unsure.

Energy flagships

5. LoadCast — electricity demand forecasting Strong MLOps story

Problem: forecast short-term load (hourly/daily) so operators can plan.

Interview line: “Forecasting isn’t accuracy alone — I report error by peak hours and monitor drift after weather regime changes.”

6. GridPulse — sensor / equipment anomaly detection

Problem: spot abnormal behaviour in SCADA-like time series before failure.

7. PowerPrice — energy price forecasting (advanced)

Day-ahead price prediction. High domain credibility for energy trading / flexibility roles; harder data cleaning. Treat as a second project after LoadCast.

How they map to your 6–8 month skills

These are domain projects — they don’t teach the curriculum, they consume the skills as you learn them:

Months 1–2 — baselines, metrics, leakage-safe splits FraudWatch v1LoadCast v1
Months 2–3 — deeper models, ablations, error analysis FraudWatch v2CreditRisk
Months 3–5 — GenAI layer (RAG, eval, citations) FilingPilotGridPulse+
Months 5–8 — API, monitoring, system-design write-up MLOps drillsDesign

Status tracker

We’ll lock a primary + secondary after you choose. Current proposal:

FraudWatch — fraud detection (Finance, classic ML) BuildingStart
FilingPilot — filings / research RAG (Finance, GenAI) Proposed #2Details
LoadCast — demand forecasting (Energy) Alt primaryDetails
GridPulse — anomaly / predictive maintenance (Energy) AltDetails
FraudWatch Week 1 is scaffolded. Finish Start here, then we add thresholds + cost matrix.

Stack & data sources

Classic ML    scikit-learn, LightGBM/XGBoost, pandas
Deep learning PyTorch (when you need sequences / custom nets)
GenAI / RAG   embeddings + Chroma/FAISS, then an LLM API
API / ship    FastAPI + simple UI; monitor latency, scores, drift
Finance data  Kaggle fraud sets, Lending-style credit, SEC EDGAR
Energy data   public ISO load + weather; NASA/C-MAPSS-style maintenance sets

What “done” looks like for interviews