diff --git a/packages/scales/src/compute.ts b/packages/scales/src/compute.ts
index 9a49edc60..b5c995554 100644
--- a/packages/scales/src/compute.ts
+++ b/packages/scales/src/compute.ts
@@ -4,56 +4,93 @@ import sortBy from 'lodash/sortBy'
 import last from 'lodash/last'
 import isDate from 'lodash/isDate'
 import { createDateNormalizer } from './timeHelpers'
-import { ScaleAxis, ScaleSpec, Series, ScaleValue, SerieAxis, OtherScaleAxis } from './types'
+import { ScaleAxis, ScaleSpec, Series, ScaleValue, SerieAxis } from './types'
 import { computeScale } from './computeScale'
 
-export const getOtherAxis = (axis: ScaleAxis): OtherScaleAxis<typeof axis> =>
-    axis === 'x' ? 'y' : 'x'
+type XY = ReturnType<typeof generateSeriesXY>
 
-const a = getOtherAxis('x')
-if (a === 'x') {
-    console.log('crap')
+type StackedXY = {
+    [K in keyof XY]: XY[K] & {
+        maxStacked: number
+        minStacked: number
+    }
+}
+
+type InputXYSeries = Record<'x' | 'y', number | string | Date | null>
+
+interface Data {
+    x: number
+    xStacked: number | null
+    y: number
+    yStacked: number | null
+
+    // Allow template literal `xStacked/yStacked` to be set on line 213
+    [key: string]: number | null
+}
+
+type XYSeries = InputXYSeries & {
+    data: Data[]
+}
+
+interface ComputedXYSeries extends InputXYSeries {
+    data: Array<{
+        data: Data
+        position: {
+            x: ScaleValue | null
+            y: ScaleValue | null
+        }
+    }>
 }
 
+type Compare = <T>(a: T, b: T) => boolean
+
+export const getOtherAxis = (axis: ScaleAxis): ScaleAxis => (axis === 'x' ? 'y' : 'x')
+
 export const compareValues = (a: string | number, b: string | number) => a === b
 export const compareDateValues = (a: Date, b: Date) => a.getTime() === b.getTime()
 
-export const computeXYScalesForSeries = (_series, xScaleSpec, yScaleSpec, width, height) => {
+export const computeXYScalesForSeries = (
+    _series: XYSeries[],
+    xScaleSpec: ScaleSpec,
+    yScaleSpec: ScaleSpec,
+    width: number,
+    height: number
+) => {
     const series = _series.map(serie => ({
         ...serie,
         data: serie.data.map(d => ({ data: { ...d } })),
-    }))
+    })) as ComputedXYSeries[]
 
-    let xy = generateSeriesXY(series, xScaleSpec, yScaleSpec)
-    if (xScaleSpec.stacked === true) {
-        stackX(yScaleSpec.type, xy, series)
+    const xy = generateSeriesXY(series, xScaleSpec, yScaleSpec)
+    if ('stacked' in xScaleSpec && xScaleSpec.stacked === true) {
+        stackX(xy as StackedXY, series)
     }
-    if (yScaleSpec.stacked === true) {
-        stackY(xScaleSpec.type, xy, series)
+    if ('stacked' in yScaleSpec && yScaleSpec.stacked === true) {
+        stackY(xy as StackedXY, series)
     }
 
-    const xScale = computeScale({ ...xScaleSpec, axis: 'x' }, xy.x, width, 'x')
-    const yScale = computeScale({ ...yScaleSpec, axis: 'y' }, xy.y, height, 'y')
+    const xScale = computeScale(xScaleSpec, xy.x, width, 'x')
+    const yScale = computeScale(yScaleSpec, xy.y, height, 'y')
 
     series.forEach(serie => {
         serie.data.forEach(d => {
             d.position = {
                 x:
-                    xScale.stacked === true
+                    'stacked' in xScale && xScale.stacked === true
                         ? d.data.xStacked === null
                             ? null
                             : xScale(d.data.xStacked)
                         : d.data.x === null
                         ? null
-                        : xScale(d.data.x),
+                        : xScale(d.data.x) ?? null,
                 y:
-                    yScale.stacked === true
+                    'stacked' in yScale && yScale.stacked === true
                         ? d.data.yStacked === null
                             ? null
                             : yScale(d.data.yStacked)
                         : d.data.y === null
                         ? null
-                        : yScale(d.data.y),
+                        : yScale(d.data.y) ?? null,
             }
         })
     })
@@ -97,8 +134,9 @@ export const generateSeriesAxis = <Axis extends ScaleAxis, Value extends ScaleVa
         series.forEach(serie => {
             serie.data.forEach(d => {
                 const value = getValue(d)
-                if (value !== null) {
-                    setValue(d, parseFloat(value))
+
+                if (value) {
+                    setValue(d, (parseFloat(String(value)) as unknown) as Value)
                 }
             })
         })
@@ -106,55 +144,61 @@ export const generateSeriesAxis = <Axis extends ScaleAxis, Value extends ScaleVa
         // `native` means we already have Date instances,
         // otherwise we have to convert the values to Date.
         const parseTime = createDateNormalizer(scaleSpec)
+
         series.forEach(serie => {
             serie.data.forEach(d => {
                 const value = getValue(d)
-                setValue(d, getValue(d) === null ? null : parseTime(getValue(d)))
+
+                if (value) {
+                    setValue(d, (parseTime(value as Date) as unknown) as Value)
+                }
             })
         })
     }
 
-    let all = []
+    const values: unknown[] = []
+
     series.forEach(serie => {
         serie.data.forEach(d => {
-            all.push(getValue(d))
+            values.push(getValue(d))
         })
     })
 
-    let min, max
-    if (scaleSpec.type === 'linear') {
-        all = uniq(all)
-        all = sortBy(all, v => v)
-        min = Math.min(...all)
-        max = Math.max(...all)
-    } else if (scaleSpec.type === 'time') {
-        all = uniqBy(all, v => v.getTime())
-        all = all
-            .slice(0)
-            .sort((a, b) => b - a)
-            .reverse()
-        min = all[0]
-        max = last(all)
-    } else {
-        all = uniq(all)
-        min = all[0]
-        max = last(all)
-    }
+    switch (scaleSpec.type) {
+        case 'linear': {
+            const all = sortBy(uniq(values as number[]), v => v)
+
+            return { all, min: Math.min(...all), max: Math.max(...all) }
+        }
+        case 'time': {
+            const all = uniqBy(values as Date[], v => v.getTime())
+                .slice(0)
+                .sort((a, b) => b.getTime() - a.getTime())
+                .reverse()
+
+            return { all, min: all[0], max: last(all) }
+        }
+        default: {
+            const all = uniq(values)
 
-    return { all, min, max }
+            return { all, min: all[0], max: last(all) }
+        }
+    }
 }
 
-export const stackAxis = (axis: ScaleAxis, otherType: ScaleAxis, xy: any, series: any) => {
+export const stackAxis = (axis: ScaleAxis, xy: StackedXY, series: ComputedXYSeries[]) => {
     const otherAxis = getOtherAxis(axis)
+    const all: number[] = []
 
-    let all = []
     xy[otherAxis].all.forEach(v => {
-        const compare = isDate(v) ? compareDateValues : compareValues
-        const stack = []
+        const compare = (isDate(v) ? compareDateValues : compareValues) as Compare
+        const stack: Array<number | null> = []
+
         series.forEach(serie => {
             const datum = serie.data.find(d => compare(d.data[otherAxis], v))
             let value = null
             let stackValue = null
+
             if (datum !== undefined) {
                 value = datum.data[axis]
                 if (value !== null) {
@@ -165,45 +209,21 @@ export const stackAxis = (axis: ScaleAxis, otherType: ScaleAxis, xy: any, series
                         stackValue = head + value
                     }
                 }
+
                 datum.data[`${axis}Stacked`] = stackValue
             }
+
             stack.push(stackValue)
-            all.push(stackValue)
+
+            if (stackValue !== null) {
+                all.push(stackValue)
+            }
         })
     })
-    all = all.filter(v => v !== null)
 
     xy[axis].minStacked = Math.min(...all)
     xy[axis].maxStacked = Math.max(...all)
 }
 
-export const stackX = (xy, otherType: ScaleAxis, series) => stackAxis('x', xy, otherType, series)
-export const stackY = (xy, otherType: ScaleAxis, series) => stackAxis('y', xy, otherType, series)
-
-export const computeAxisSlices = (axis: ScaleAxis, data) => {
-    const otherAxis = getOtherAxis(axis)
-
-    return data[otherAxis].all.map(v => {
-        const slice = {
-            id: v,
-            [otherAxis]: data[`${otherAxis}Scale`](v),
-            data: [],
-        }
-        const compare = isDate(v) ? compareDateValues : compareValues
-        data.series.forEach(serie => {
-            const datum = serie.data.find(d => compare(d.data[otherAxis], v))
-            if (datum !== undefined) {
-                slice.data.push({
-                    ...datum,
-                    serie,
-                })
-            }
-        })
-        slice.data.reverse()
-
-        return slice
-    })
-}
-
-export const computeXSlices = data => computeAxisSlices('x', data)
-export const computeYSlices = data => computeAxisSlices('y', data)
+const stackX = (xy: StackedXY, series: ComputedXYSeries[]) => stackAxis('x', xy, series)
+const stackY = (xy: StackedXY, series: ComputedXYSeries[]) => stackAxis('y', xy, series)
diff --git a/packages/scales/src/computeScale.ts b/packages/scales/src/computeScale.ts
index a96c44018..be57af625 100644
--- a/packages/scales/src/computeScale.ts
+++ b/packages/scales/src/computeScale.ts
@@ -1,20 +1,4 @@
-import {
-    ScaleAxis,
-    ScaleBand,
-    ScaleBandSpec,
-    ScalePoint,
-    ScalePointSpec,
-    ScaleSpec,
-    ComputedSerieAxis,
-    ScaleValue,
-    StringValue,
-    NumericValue,
-    ScaleLinear,
-    ScaleLinearSpec,
-    ScaleLogSpec,
-    ScaleLog,
-    ScaleSymLogSpec,
-} from './types'
+import { ScaleAxis, ScaleSpec, ComputedSerieAxis, ScaleValue } from './types'
 import { createLinearScale } from './linearScale'
 import { createPointScale } from './pointScale'
 import { createBandScale } from './bandScale'
@@ -22,65 +6,26 @@ import { createTimeScale } from './timeScale'
 import { createLogScale } from './logScale'
 import { createSymLogScale } from './symLogScale'
 
-// override for linear scale
-export function computeScale<Input extends NumericValue>(
-    spec: ScaleLinearSpec,
-    data: ComputedSerieAxis<Input>,
-    size: number,
-    axis: ScaleAxis
-): ScaleLinear<Input>
-
-// override for point scale
-export function computeScale<Input extends StringValue>(
-    spec: ScalePointSpec,
-    data: ComputedSerieAxis<Input>,
-    size: number,
-    axis: ScaleAxis
-): ScalePoint<Input>
-
-// override for band scale
-export function computeScale<Input extends StringValue>(
-    spec: ScaleBandSpec,
-    data: ComputedSerieAxis<Input>,
-    size: number,
-    axis: ScaleAxis
-): ScaleBand<Input>
-
-// override for log scale
-export function computeScale(
-    spec: ScaleLogSpec,
-    data: ComputedSerieAxis<number>,
-    size: number,
-    axis: ScaleAxis
-): ScaleLog
-
-// override for symlog scale
-export function computeScale(
-    spec: ScaleSymLogSpec,
-    data: ComputedSerieAxis<number>,
-    size: number,
-    axis: ScaleAxis
-): ScaleLog
-
-export function computeScale<Input extends ScaleValue, Output>(
+export function computeScale<Input extends ScaleValue>(
     spec: ScaleSpec,
-    data: ComputedSerieAxis<Input>,
+    data: ComputedSerieAxis<any>,
     size: number,
     axis: ScaleAxis
 ) {
-    if (spec.type === 'linear') {
-        return createLinearScale(spec, data, size, axis)
-    } else if (spec.type === 'point') {
-        return createPointScale<Input>(spec, data, size)
-    } else if (spec.type === 'band') {
-        return createBandScale<Input>(spec, data, size)
-    } else if (spec.type === 'time') {
-        return createTimeScale(spec, data, size)
-    } else if (spec.type === 'log') {
-        return createLogScale(spec, data, size, axis)
-    } else if (spec.type === 'symlog') {
-        return createSymLogScale(spec, data, size, axis)
+    switch (spec.type) {
+        case 'linear':
+            return createLinearScale(spec, data, size, axis)
+        case 'point':
+            return createPointScale<Input>(spec, data, size)
+        case 'band':
+            return createBandScale<Input>(spec, data, size)
+        case 'time':
+            return createTimeScale(spec, data, size)
+        case 'log':
+            return createLogScale(spec, data, size, axis)
+        case 'symlog':
+            return createSymLogScale(spec, data, size, axis)
+        default:
+            throw new Error('invalid scale spec')
     }
-
-    throw new Error('invalid scale spec')
 }
diff --git a/packages/scales/src/timeScale.ts b/packages/scales/src/timeScale.ts
index 4fa720f11..4a14878e4 100644
--- a/packages/scales/src/timeScale.ts
+++ b/packages/scales/src/timeScale.ts
@@ -2,7 +2,7 @@ import { NumberValue, scaleTime, scaleUtc } from 'd3-scale'
 import { createDateNormalizer } from './timeHelpers'
 import { ComputedSerieAxis, ScaleTime, ScaleTimeSpec } from './types'
 
-export const createTimeScale = <Input extends Date | NumberValue, Output>(
+export const createTimeScale = <Input extends Date | NumberValue>(
     {
         format = 'native',
         precision = 'millisecond',
@@ -41,7 +41,7 @@ export const createTimeScale = <Input extends Date | NumberValue, Output>(
     if (nice === true) scale.nice()
     else if (typeof nice === 'object' || typeof nice === 'number') scale.nice(nice)
 
-    const typedScale = (scale as unknown) as ScaleTime<Input, Output>
+    const typedScale = (scale as unknown) as ScaleTime<Input>
 
     typedScale.type = 'time'
     typedScale.useUTC = useUTC
diff --git a/packages/scales/src/types.ts b/packages/scales/src/types.ts
index abe9619cf..2a07fc128 100644
--- a/packages/scales/src/types.ts
+++ b/packages/scales/src/types.ts
@@ -117,8 +117,7 @@ export type ScaleTimeSpec = {
     nice?: boolean
 }
 
-export interface ScaleTime<Input extends Date | NumberValue, Output>
-    extends D3ScaleTime<Input, Output> {
+export interface ScaleTime<Input extends Date | NumberValue> extends D3ScaleTime<Input, Date> {
     type: 'time'
     useUTC: boolean
 }
@@ -141,7 +140,7 @@ export type SerieAxis<Axis extends ScaleAxis, Value extends ScaleValue> = {
 export type ComputedSerieAxis<Value extends ScaleValue> = {
     all: Value[]
     min: Value
-    minStacked: Value
+    minStacked?: Value
     max: Value
-    maxStacked: Value
+    maxStacked?: Value
 }