Data
Visualization
—
Technical
Skills
CONT ENT S
01
Programming
Languages
&
Core
Libraries
02
Visualization
Libraries
&
Frameworks
03
Data
Preparation
,
Query
&
Modeling
04
Statistical
&
Analytical
Methods
05
Visual
Encoding
&
Chart
Design
06
Color
,
Typography
&
Layout
Systems
07
Interactivity
&
Front
-
End
Delivery
08
Geospatial
&
Network
Visualization
09
BI
Platforms
&
Dashboard
Engineering
10
Storytelling
,
Accessibility
&
Ethics
01
Programming
Languages
&
Core
Libraries
Python
for
data
analysis
pandas
,
NumPy
,
Polars
—
reshaping
,
joins
,
grouped
aggregation
,
DataFrame
pipelines
.
R
for
statistical
graphics
tidyverse
,
dplyr
,
tidyr
—
vectorized
manipulation
and
modeling
-
ready
data
frames
.
JavaScript
/
TypeScript
ES
2022,
DOM
and
SVG
APIs
,
module
bundling
with
Vite
,
Rollup
,
or
esbuild
.
SQL
for
chart
-
ready
extracts
Window
functions
,
CTEs
,
date
bucketing
,
cohort
and
funnel
queries
.
HTML
5
Canvas
&
SVG
Direct
drawing
surfaces
for
custom
marks
,
axes
,
annotation
layers
,
and
hit
testing
.
Notebook
authoring
Jupyter
,
JupyterLab
,
Observable
,
Quarto
,
R
Markdown
—
reproducible
figure
generation
.
Numerical
computing
SciPy
,
NumPy
broadcasting
,
matrix
operations
for
scientific
and
volumetric
plots
.
Julia
/
MATLAB
Array
-
heavy
numerical
work
and
engineering
plot
output
(
working
proficiency
).
T O O LING
Python
R
TypeScript
SQL
Jupyter
Quarto
1 / 6
02
Visualization
Libraries
&
Frameworks
D
3.
js
Scales
,
axes
,
selections
,
data
joins
,
force
,
hierarchy
and
chord
layouts
.
Vega
&
Vega
-
Lite
Declarative
grammar
-
of
-
graphics
specs
,
layered
views
,
faceting
,
interactive
bindings
.
Observable
Plot
Fast
exploratory
marks
with
sensible
defaults
and
composable
transforms
.
ggplot
2
Grammar
of
graphics
,
facets
,
themes
,
custom
geoms
,
stats
,
and
scale
extensions
.
Matplotlib
&
Seaborn
Publication
figures
,
statistical
plots
,
style
sheets
,
and
colour
-
bar
control
.
Plotly
&
Dash
Interactive
charts
and
analytical
web
apps
with
callback
-
driven
updates
.
Component
chart
libraries
Chart
.
js
,
Apache
ECharts
,
Highcharts
,
ApexCharts
,
Recharts
in
production
UIs
.
Python
declarative
&
interactive
Altair
,
Bokeh
,
HoloViews
,
Panel
for
linked
and
server
-
backed
visualizations
.
GPU
&
high
-
density
rendering
deck
.
gl
,
regl
,
Three
.
js
,
WebGL
instancing
for
millions
of
marks
or
3
D
scenes
.
Grammar
-
of
-
graphics
fluency
Moving
cleanly
between
ggplot
2,
Vega
-
Lite
,
and
D
3
with
equivalent
chart
logic
.
T O O LING
D
3.
js
Vega
-
Lite
ggplot
2
Plotly
ECharts
deck
.
gl
03
Data
Preparation
,
Query
&
Modeling
Data
wrangling
&
cleaning
Type
coercion
,
missing
-
value
strategy
,
deduplication
,
outlier
review
before
plotting
.
ETL
/
ELT
pipelines
Airflow
,
Dagster
,
dbt
,
Dataform
—
scheduled
transforms
feeding
dashboards
.
Warehouse
&
lakehouse
querying
Snowflake
,
BigQuery
,
Redshift
,
Databricks
,
DuckDB
,
Athena
.
Analytical
data
modeling
Star
schema
,
slowly
changing
dimensions
,
bridge
tables
,
grain
definition
.
Semantic
&
metric
layers
LookML
,
MetricFlow
,
Cube
—
one
certified
definition
per
metric
.
Large
-
scale
processing
Spark
,
PySpark
,
Parquet
,
Arrow
columnar
formats
,
partitioning
strategy
.
Data
quality
&
validation
Freshness
checks
,
row
-
count
assertions
,
reconciliation
before
publication
.
Sampling
&
aggregation
trade
-
offs
Choosing
rollups
,
binning
,
and
pre
-
aggregation
without
distorting
the
signal
.
T O O LING
dbt
Airflow
Snowflake
BigQuery
DuckDB
Spark
2 / 6
04
Statistical
&
Analytical
Methods
Exploratory
data
analysis
Structured
EDA
workflow
—
shape
,
spread
,
outliers
,
subgroup
scan
,
anomaly
flags
.
Distribution
analysis
Histograms
,
KDE
,
ECDF
,
box
,
violin
,
and
ridge
plots
with
consistent
bins
.
Correlation
&
regression
diagnostics
Scatter
matrices
,
residual
plots
,
LOESS
fits
,
leverage
and
influence
checks
.
Time
-
series
visualization
Decomposition
,
seasonality
bands
,
rolling
windows
,
forecast
intervals
.
Uncertainty
representation
Confidence
intervals
,
error
bars
,
bootstrapped
bands
,
fan
charts
,
ensemble
spread
.
Dimensionality
reduction
PCA
,
t
-
SNE
,
UMAP
for
embedding
plots
,
cluster
views
,
and
neighbourhood
maps
.
Bayesian
visualization
Posterior
densities
,
credible
intervals
,
trace
and
forest
plots
.
Survey
&
weighted
data
Weighted
crosstabs
,
margin
-
of
-
error
reporting
,
Likert
and
diverging
stacked
bars
.
A
/
B
test
reporting
Effect
sizes
with
intervals
,
sequential
-
testing
caveats
,
segment
breakdowns
.
Model
evaluation
visuals
ROC
/
PR
curves
,
calibration
plots
,
confusion
matrices
,
feature
-
importance
charts
.
T O O LING
pandas
statsmodels
scikit
-
learn
SciPy
tidymodels
05
Visual
Encoding
&
Chart
Design
Perceptual
encoding
selection
Ranking
position
,
length
,
angle
,
area
,
volume
,
colour
,
and
shape
by
accuracy
.
Chart
selection
by
task
Comparison
,
distribution
,
relationship
,
composition
,
change
over
time
,
flow
,
spatial
.
Small
multiples
&
faceting
Shared
scales
,
aligned
axes
,
cohort
grids
,
and
trellis
ordering
that
aids
scanning
.
Annotation
systems
Direct
labelling
,
reference
lines
,
thresholds
,
event
markers
,
and
callout
design
.
Composite
&
blended
charts
Bullet
charts
,
slope
graphs
,
Sankey
,
alluvial
,
waterfall
,
and
dual
-
axis
avoidance
.
Table
&
micro
-
chart
design
Sparklines
,
in
-
cell
bars
,
conditional
formatting
,
tabular
figures
.
Chart
junk
audit
Removing
unnecessary
gridlines
, 3
D
effects
,
redundant
legends
,
and
decorative
fills
.
Axis
and
scale
decisions
Log
vs
.
linear
,
zero
baseline
rules
,
banding
,
tick
density
,
and
unit
notation
.
T O O LING
D
3
scales
Vega
-
Lite
Altair
Figma
Tableau
3 / 6
06
Color
,
Typography
&
Layout
Systems
Colour
theory
for
data
Sequential
,
diverging
,
cyclic
,
and
categorical
palettes
matched
to
data
type
.
Palette
construction
ColorBrewer
,
viridis
family
,
OKLCH
/
HCL
interpolation
,
colourblind
-
safe
sets
.
Contrast
management
WCAG
2.2
contrast
ratios
,
light
/
dark
theming
,
print
-
safe
colour
separations
.
Typographic
hierarchy
Axis
label
sizing
,
tabular
numerals
,
unit
formatting
,
label
depopulation
rules
.
Layout
grid
&
whitespace
Aspect
-
ratio
selection
,
panel
rhythm
,
baseline
grid
alignment
,
density
control
.
Design
systems
for
charts
Tokenized
themes
,
reusable
chart
components
,
documented
style
guides
.
Print
&
screen
calibration
Vector
export
,
raster
resolution
,
hairlines
,
and
greyscale
legibility
checks
.
T O O LING
ColorBrewer
viridis
Chroma
.
js
OKLCH
Figma
tokens
07
Interactivity
&
Front
-
End
Delivery
Interaction
patterns
Hover
tooltips
,
crossfiltering
,
linked
brushing
,
drill
-
down
,
brush
-
and
-
zoom
.
Responsive
chart
layout
Fluid
SVG
viewBox
,
container
queries
,
mobile
-
first
sizing
and
touch
targets
.
Animation
&
transitions
Data
-
driven
transitions
,
easing
,
restrained
motion
,
prefers-
reduced-motion
support
.
Front
-
end
performance
Virtualization
,
memoization
,
Web
Workers
,
debounced
re
-
renders
,
frame
budgeting
.
Real
-
time
&
streaming
charts
WebSocket
and
SSE
feeds
,
ring
buffers
,
rolling
windows
,
backpressure
handling
.
Export
&
publishing
PDF
and
print
export
,
PNG
/
SVG
capture
,
embedded
iframes
,
static
site
deployment
.
Visual
regression
testing
Playwright
screenshot
diffs
,
snapshot
fixtures
,
chart
rendering
assertions
.
T O O LING
D
3
transitions
CSS
WebSockets
Vite
Playwright
4 / 6
08
Geospatial
&
Network
Visualization
Projections
&
geodata
formats
GeoJSON
,
TopoJSON
,
WKT
,
shapefiles
,
vector
tiles
,
coordinate
systems
.
Map
chart
types
Choropleth
,
dot
density
,
proportional
symbol
,
hexbin
,
isochrone
,
flow
maps
.
Web
mapping
libraries
Leaflet
,
Mapbox
GL
JS
,
MapLibre
,
deck
.
gl
,
Kepler
.
gl
for
interactive
maps
.
GIS
toolchain
QGIS
,
PostGIS
,
GeoPandas
,
GDAL
for
spatial
joins
and
geoprocessing
.
Network
&
graph
visualization
Force
-
directed
,
Sankey
,
chord
,
arc
,
and
matrix
views
;
Gephi
,
Cytoscape
,
Graphviz
.
Hierarchy
&
flow
layouts
Treemaps
,
sunbursts
,
icicle
plots
,
tree
and
DAG
layouts
with
path
highlighting
.
T O O LING
Mapbox
GL
Leaflet
deck
.
gl
QGIS
GeoPandas
Gephi
09
BI
Platforms
&
Dashboard
Engineering
BI
platform
fluency
Tableau
,
Power
BI
,
Looker
,
Looker
Studio
,
Mode
,
Metabase
,
Superset
,
Sigma
.
Dashboard
architecture
KPI
tiles
,
drill
paths
,
filter
panels
,
narrative
headers
,
progressive
disclosure
.
Semantic
layer
governance
Certified
datasets
,
metric
definitions
,
row
-
level
security
,
access
modelling
.
Query
performance
tuning
Extracts
and
aggregates
,
query
plans
,
incremental
refresh
,
result
caching
.
Embedded
analytics
Embedding
APIs
,
SSO
,
multi
-
tenant
filtering
,
white
-
label
reporting
.
Visualization
governance
Versioning
,
publishing
review
,
usage
monitoring
,
retirement
of
stale
dashboards
.
T O O LING
Tableau
Power
BI
Looker
Metabase
Superset
10
Storytelling
,
Accessibility
&
Ethics
Narrative
structure
Headline
-
first
framing
,
scrollytelling
,
annotated
walkthroughs
,
chaptered
reports
.
Audience
adaptation
Executive
summary
charts
vs
.
analyst
detail
views
;
tailoring
density
and
framing
.
Accessibility
engineering
Alt
text
and
data
tables
,
keyboard
navigation
,
ARIA
roles
,
pattern
fills
beyond
colour
.
Ethics
&
data
integrity
Zero
-
baseline
checks
,
truncated
axes
,
dual
-
axis
misuse
,
Simpson
'
s
paradox
,
bias
disclosure
.
Chart
critique
&
peer
review
Rubric
-
based
review
,
before
/
after
critique
,
pre
-
publication
fact
checks
.
Documentation
&
provenance
Methodology
notes
,
source
citations
,
tooltip
definitions
,
data
lineage
references
.
Stakeholder
enablement
Chart
literacy
workshops
,
template
handoffs
,
self
-
serve
chart
guidelines
.
T O O LING
axe
DevTools
WAVE
Notion
Quarto
Figma
5 / 6
—
Proficiency
Matrix
at
a
Glance
Self
-
assessed
levels
across
the
ten
competency
areas
,
based
on
production
use
in
analytical
reporting
and
product
analytics
.
CO MPET ENCY
AREA
SIGNAT URE
T O O LS
&
MET HO DS
LEVEL
Visualization
programming
D
3.
js
,
SVG
,
Canvas
,
TypeScript
Advanced
Declarative
&
grammar
-
of
-
graphics
Vega
-
Lite
,
Observable
Plot
,
ggplot
2,
Altair
Advanced
Statistical
computing
&
analysis
Python
,
R
,
pandas
,
statsmodels
,
scikit
-
learn
Advanced
Data
query
&
modeling
SQL
,
dbt
,
LookML
,
Snowflake
,
DuckDB
Advanced
Dashboard
engineering
Tableau
,
Power
BI
,
Looker
,
Metabase
,
Superset
Proficient
Geospatial
&
network
visualization
Mapbox
GL
,
deck
.
gl
,
QGIS
,
GeoPandas
,
Gephi
Proficient
Visual
design
systems
ColorBrewer
,
viridis
,
OKLCH
,
typography
,
Figma
Advanced
Accessibility
&
ethics
WCAG
2.2,
ARIA
,
alt
text
&
data
tables
,
integrity
checks
Proficient
Performance
&
large
data
WebGL
,
Parquet
,
DuckDB
,
Web
Workers
,
caching
Proficient
Storytelling
&
delivery
Quarto
,
Observable
,
PDF
/
print
export
,
narrative
layout
Advanced
6 / 6
