Learn Anomaly Detection with Phoebe

How machines spot what does not belong

The idea behind every fraud alert, outage page, quality reject, and intrusion warning - explained end to end. A leader track that makes every kind of anomaly and every method click in plain English (with a visual for each), and a builder track that implements them in real Python: statistical detectors, distance and density, isolation forests, one-class methods, time-series change detection, and a look at deep models. You even drive a live detector in the browser. And the whole team pipeline - analyst to data scientist to engineering to on-call - laid out so you know who does what.

2tracks
16sessions
45min per session
1live detector you drive

The leader track 🀝 · for PMs, product & business leaders · 6 x 45 min · no code, ever

Thinking mode: what an anomaly really is, the kinds you will meet, the ladder of methods and when each fits, who on the team does what, and why measuring detection is a trap for the unwary - each session ends with the questions to ask your team.

The builder track πŸ› οΈ Β· for analysts, data scientists & engineers Β· 10 x 45 min Β· Python + a notebook

One running series, Lumen's daily web sessions with four hidden anomalies, threaded through the demos: you implement each family of detector in real Python and follow one detection from the analyst's first plot to a monitored, alerting production system.

πŸ—οΈ Builder 1 Β· easy

Anomaly foundations

The labelled Lumen series, the three anomaly types, the base-rate problem that makes accuracy lie, and the z-score baseline every detector must beat.

β–Ά Builders start here
πŸ“ Builder 2 Β· easy

Statistical detectors

Z-score and the three-sigma rule, IQR and Tukey fences, and robust MAD - and why the robust versions survive their own outliers.

Lumen thresholds
〰️ Builder 3 Β· medium

Rolling & seasonal detectors

Rolling mean and std, EWMA, and the STL-residual detector that finally catches the contextual anomaly - plus a live detector you drive.

β˜… interactive: anomaly-live
πŸ•ΈοΈ Builder 4 Β· medium

Distance & density

kNN distance to nearest neighbours, and the Local Outlier Factor - flagging points that sit in a sparser neighbourhood than their peers.

LOF, cited
🌲 Builder 5 · hands-on

Isolation Forest

Anomalies are few and different, so random splits isolate them fast - the elegant tree-based detector (Liu, Ting & Zhou 2008) in scikit-learn.

Isolation Forest
β­• Builder 6 Β· hands-on

One-class & covariance

Learn the shape of "normal" and flag departures: One-Class SVM and the Elliptic Envelope - the semi-supervised, normal-only approach.

Novelty detection
πŸ“ˆ Builder 7 Β· hands-on

Time-series anomalies

Change-point detection, CUSUM, and forecast-residual anomalies - detecting when the series shifts, tying straight back to the forecasting course.

Change detection
πŸ€– Builder 8 Β· hardest

Deep anomaly detection

Autoencoder reconstruction error and LSTM autoencoders - where deep methods help and where they do not, surveyed and cited (Pang et al. 2021).

The frontier, cited
πŸ“Š Builder 9 Β· medium

Evaluation

Precision, recall, F1, and PR-AUC, point-adjustment for time series, threshold tuning, and handling brutal class imbalance - the honest scoreboard.

Score the detector
🚨 Builder 10 · hardest

Productionizing & alerting

Streaming detection, alert routing and deduplication, the feedback loop from on-call, and monitoring the detector so it never quietly rots.

Lumen on call
easy - everyone medium hands-on / deciding hardest
An honest note on detection: anomalies are rare, so accuracy lies - a detector that flags nothing is 99% accurate and useless. This course measures with precision and recall from the first session, treats alert fatigue as the real failure mode, and teaches the published canon - the Chandola survey, LOF, Isolation Forest, and One-Class SVM - honestly. Most real detection is unsupervised; labels are scarce and late. Deep methods are surveyed and cited, not trained from scratch. The live detector is real math on a small labelled teaching series, not a production system.

Choose your path πŸ—ΊοΈ

Two doors, one course. Leaders get the concepts and the pipeline; builders implement every detector in Python - and both meet at the live detector.

🀝 Leader (no code, ever) a1β†’ a2β†’ a3β†’ a4β†’ a5β†’ a6
πŸ› οΈ Builder (implement in Python) b1β†’ b2β†’ b3β†’ b4β†’ b5β†’ b6β†’ b7β†’ b8β†’ b9β†’ b10
🌱 Curious follower (a taste) a1β†’ a2β†’ b3
πŸš€ Full journey (understand AND build) a1-a6β†’ b1-b10

The knowledge map 🧠

Both tracks at a glance - hover a session to spotlight its concepts, click any node to jump in.