diff --git a/day-22/benchmark b/day-22/benchmark
new file mode 100644
index 0000000..728f20a
--- /dev/null
+++ b/day-22/benchmark
@@ -0,0 +1,15 @@
+goos: linux
+goarch: amd64
+pkg: github.com/onyx-and-iris/aoc2024/day-22
+cpu: Intel(R) Core(TM) i7-8700K CPU @ 3.70GHz
+BenchmarkSolve-12    	       1	2054969661 ns/op
+BenchmarkSolve-12    	       1	1820308129 ns/op
+BenchmarkSolve-12    	       1	1853098610 ns/op
+BenchmarkSolve-12    	       1	1825725443 ns/op
+BenchmarkSolve-12    	       1	1817395243 ns/op
+BenchmarkSolve-12    	       1	1823292443 ns/op
+BenchmarkSolve-12    	       1	1825067743 ns/op
+BenchmarkSolve-12    	       1	1827243915 ns/op
+BenchmarkSolve-12    	       1	1821714708 ns/op
+BenchmarkSolve-12    	       1	1825390608 ns/op
+ok  	github.com/onyx-and-iris/aoc2024/day-22	18.538s
diff --git a/day-22/cmd/cli/main.go b/day-22/cmd/cli/main.go
new file mode 100644
index 0000000..28f204d
--- /dev/null
+++ b/day-22/cmd/cli/main.go
@@ -0,0 +1,41 @@
+/********************************************************************************
+    Advent of Code 2024 - day-22
+********************************************************************************/
+
+package main
+
+import (
+	"embed"
+	"flag"
+	"fmt"
+	"slices"
+
+	log "github.com/sirupsen/logrus"
+
+	problems "github.com/onyx-and-iris/aoc2024/day-22"
+)
+
+//go:embed testdata
+var files embed.FS
+
+func main() {
+	filename := flag.String("f", "input.txt", "input file")
+	loglevel := flag.Int("l", int(log.InfoLevel), "log level")
+	flag.Parse()
+
+	if slices.Contains(log.AllLevels, log.Level(*loglevel)) {
+		log.SetLevel(log.Level(*loglevel))
+	}
+
+	data, err := files.ReadFile(fmt.Sprintf("testdata/%s", *filename))
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	one, two, err := problems.Solve(data)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	fmt.Printf("solution one: %d\nsolution two: %d\n", one, two)
+}
diff --git a/day-22/go.mod b/day-22/go.mod
new file mode 100644
index 0000000..06575ad
--- /dev/null
+++ b/day-22/go.mod
@@ -0,0 +1,7 @@
+module github.com/onyx-and-iris/aoc2024/day-22
+
+go 1.23.3
+
+require github.com/sirupsen/logrus v1.9.3
+
+require golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8 // indirect
diff --git a/day-22/go.sum b/day-22/go.sum
new file mode 100644
index 0000000..21f9bfb
--- /dev/null
+++ b/day-22/go.sum
@@ -0,0 +1,15 @@
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ=
+github.com/sirupsen/logrus v1.9.3/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8 h1:0A+M6Uqn+Eje4kHMK80dtF3JCXC4ykBgQG4Fe06QRhQ=
+golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/day-22/internal/one/benchmark b/day-22/internal/one/benchmark
new file mode 100644
index 0000000..2c173d8
--- /dev/null
+++ b/day-22/internal/one/benchmark
@@ -0,0 +1,6 @@
+goos: linux
+goarch: amd64
+pkg: github.com/onyx-and-iris/aoc2024/day-22/internal/one
+cpu: Intel(R) Core(TM) i7-8700K CPU @ 3.70GHz
+BenchmarkSolve-12    	1000000000	         0.03026 ns/op
+ok  	github.com/onyx-and-iris/aoc2024/day-22/internal/one	0.219s
diff --git a/day-22/internal/one/solve.go b/day-22/internal/one/solve.go
new file mode 100644
index 0000000..ad1a43b
--- /dev/null
+++ b/day-22/internal/one/solve.go
@@ -0,0 +1,29 @@
+package one
+
+import (
+	"bytes"
+
+	"github.com/onyx-and-iris/aoc2024/day-22/internal/randomiser"
+)
+
+const numIterations = 2000
+
+func Solve(buf []byte) (int, error) {
+	r := bytes.NewReader(buf)
+	secrets, err := parseLines(r)
+	if err != nil {
+		return 0, err
+	}
+
+	var sum int
+	for _, secret := range secrets {
+		randomiser := randomiser.New(secret)
+
+		for range numIterations {
+			randomiser.Randomise()
+		}
+		sum += randomiser.Secret()
+	}
+
+	return sum, nil
+}
diff --git a/day-22/internal/one/solve_internal_test.go b/day-22/internal/one/solve_internal_test.go
new file mode 100644
index 0000000..e5fd7ea
--- /dev/null
+++ b/day-22/internal/one/solve_internal_test.go
@@ -0,0 +1,15 @@
+package one
+
+import (
+	_ "embed"
+	"os"
+	"testing"
+)
+
+//go:embed testdata/input.txt
+var data []byte
+
+func BenchmarkSolve(b *testing.B) {
+	os.Stdout, _ = os.Open(os.DevNull)
+	Solve(data)
+}
diff --git a/day-22/internal/one/util.go b/day-22/internal/one/util.go
new file mode 100644
index 0000000..b3d7400
--- /dev/null
+++ b/day-22/internal/one/util.go
@@ -0,0 +1,31 @@
+package one
+
+import (
+	"bufio"
+	"io"
+	"strconv"
+	"strings"
+)
+
+func parseLines(r io.Reader) ([]int, error) {
+	secrets := []int{}
+
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		secrets = append(secrets, mustConv(strings.TrimSpace(scanner.Text())))
+	}
+
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+
+	return secrets, nil
+}
+
+func mustConv(s string) int {
+	n, err := strconv.Atoi(s)
+	if err != nil {
+		panic(err)
+	}
+	return n
+}
diff --git a/day-22/internal/randomiser/randomiser.go b/day-22/internal/randomiser/randomiser.go
new file mode 100644
index 0000000..96d97cf
--- /dev/null
+++ b/day-22/internal/randomiser/randomiser.go
@@ -0,0 +1,43 @@
+package randomiser
+
+type Randomiser struct {
+	secret int
+}
+
+func New(secret int) *Randomiser {
+	return &Randomiser{secret: secret}
+}
+
+func (r *Randomiser) multiplyBy(n int) int {
+	return r.secret * n
+}
+
+func (r *Randomiser) divideBy(n int) int {
+	return r.secret / n
+}
+
+func (r *Randomiser) mix(a int) {
+	r.secret ^= a
+}
+
+func (r *Randomiser) prune() {
+	r.secret %= 16777216
+}
+
+func (r *Randomiser) Randomise() {
+	res := r.multiplyBy(64)
+	r.mix(res)
+	r.prune()
+
+	res = r.divideBy(32)
+	r.mix(res)
+	r.prune()
+
+	res = r.multiplyBy(2048)
+	r.mix(res)
+	r.prune()
+}
+
+func (r *Randomiser) Secret() int {
+	return r.secret
+}
diff --git a/day-22/internal/randomiser/randomiser_internal_test.go b/day-22/internal/randomiser/randomiser_internal_test.go
new file mode 100644
index 0000000..6690237
--- /dev/null
+++ b/day-22/internal/randomiser/randomiser_internal_test.go
@@ -0,0 +1,19 @@
+package randomiser
+
+import "testing"
+
+func TestRandomiserMix(t *testing.T) {
+	r := New(42)
+	r.mix(15)
+	if r.secret != 37 {
+		t.Errorf("r.secret: got = %d want = 3", r.secret)
+	}
+}
+
+func TestRandomiserPrune(t *testing.T) {
+	r := New(10e7)
+	r.prune()
+	if r.secret != 16113920 {
+		t.Errorf("r.secret: got = %d want = 16113920", r.secret)
+	}
+}
diff --git a/day-22/internal/two/benchmark b/day-22/internal/two/benchmark
new file mode 100644
index 0000000..bdea7c6
--- /dev/null
+++ b/day-22/internal/two/benchmark
@@ -0,0 +1,6 @@
+goos: linux
+goarch: amd64
+pkg: github.com/onyx-and-iris/aoc2024/day-22/internal/two
+cpu: Intel(R) Core(TM) i7-8700K CPU @ 3.70GHz
+BenchmarkSolve-12    	       1	2064547562 ns/op
+ok  	github.com/onyx-and-iris/aoc2024/day-22/internal/two	2.091s
diff --git a/day-22/internal/two/cache.go b/day-22/internal/two/cache.go
new file mode 100644
index 0000000..f6a6542
--- /dev/null
+++ b/day-22/internal/two/cache.go
@@ -0,0 +1,21 @@
+package two
+
+import "sync"
+
+type sequenceCache struct {
+	mu   sync.RWMutex
+	data map[sequence]int
+}
+
+func newSequenceCache() sequenceCache {
+	return sequenceCache{
+		data: make(map[sequence]int),
+	}
+}
+
+func (sc *sequenceCache) upsert(seq sequence, value int) {
+	sc.mu.Lock()
+	defer sc.mu.Unlock()
+
+	sc.data[seq] += value
+}
diff --git a/day-22/internal/two/sequence.go b/day-22/internal/two/sequence.go
new file mode 100644
index 0000000..632f7d0
--- /dev/null
+++ b/day-22/internal/two/sequence.go
@@ -0,0 +1,7 @@
+package two
+
+type sequence [4]int
+
+func (s *sequence) shift(next int) {
+	s[0], s[1], s[2], s[3] = s[1], s[2], s[3], next
+}
diff --git a/day-22/internal/two/solve.go b/day-22/internal/two/solve.go
new file mode 100644
index 0000000..829b09a
--- /dev/null
+++ b/day-22/internal/two/solve.go
@@ -0,0 +1,56 @@
+package two
+
+import (
+	"bytes"
+	"math"
+
+	"github.com/onyx-and-iris/aoc2024/day-22/internal/randomiser"
+)
+
+const numIterations = 2000
+
+func Solve(buf []byte) (int, error) {
+	r := bytes.NewReader(buf)
+	secrets, err := parseLines(r)
+	if err != nil {
+		return 0, err
+	}
+
+	conc := len(secrets)
+	done := make(chan bool)
+
+	sequences := newSequenceCache()
+	for _, secret := range secrets {
+		go func() {
+			seen := make(map[sequence]struct{})
+			sequence := sequence{math.MaxInt, math.MaxInt, math.MaxInt, math.MaxInt}
+
+			randomiser := randomiser.New(secret)
+			for range numIterations {
+				prev := lastDigit(randomiser.Secret())
+				randomiser.Randomise()
+
+				sequence.shift(prev - lastDigit(randomiser.Secret()))
+
+				_, ok := seen[sequence]
+				if !ok {
+					seen[sequence] = struct{}{}
+					sequences.upsert(sequence, lastDigit(randomiser.Secret()))
+				}
+			}
+			done <- true
+		}()
+	}
+
+	for range conc {
+		<-done
+	}
+
+	max := 0
+	for _, sum := range sequences.data {
+		if sum > max {
+			max = sum
+		}
+	}
+	return max, nil
+}
diff --git a/day-22/internal/two/solve_internal_test.go b/day-22/internal/two/solve_internal_test.go
new file mode 100644
index 0000000..ecb05d5
--- /dev/null
+++ b/day-22/internal/two/solve_internal_test.go
@@ -0,0 +1,15 @@
+package two
+
+import (
+	_ "embed"
+	"os"
+	"testing"
+)
+
+//go:embed testdata/input.txt
+var data []byte
+
+func BenchmarkSolve(b *testing.B) {
+	os.Stdout, _ = os.Open(os.DevNull)
+	Solve(data)
+}
diff --git a/day-22/internal/two/util.go b/day-22/internal/two/util.go
new file mode 100644
index 0000000..7407209
--- /dev/null
+++ b/day-22/internal/two/util.go
@@ -0,0 +1,35 @@
+package two
+
+import (
+	"bufio"
+	"io"
+	"strconv"
+	"strings"
+)
+
+func parseLines(r io.Reader) ([]int, error) {
+	secrets := []int{}
+
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		secrets = append(secrets, mustConv(strings.TrimSpace(scanner.Text())))
+	}
+
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+
+	return secrets, nil
+}
+
+func mustConv(s string) int {
+	n, err := strconv.Atoi(s)
+	if err != nil {
+		panic(err)
+	}
+	return n
+}
+
+func lastDigit(n int) int {
+	return n % 10
+}
diff --git a/day-22/makefile b/day-22/makefile
new file mode 100644
index 0000000..1fc6528
--- /dev/null
+++ b/day-22/makefile
@@ -0,0 +1,30 @@
+program = day-22
+
+GO = go
+SRC_DIR := src
+BIN_DIR := bin
+
+EXE := $(BIN_DIR)/$(program)
+
+.DEFAULT_GOAL := build
+
+.PHONY: fmt vet build bench clean
+fmt:        
+	$(GO) fmt ./...
+
+vet: fmt        
+	$(GO) vet ./...
+
+build: vet | $(BIN_DIR)
+	$(GO) build -o $(EXE) ./$(SRC_DIR)
+
+bench:
+	$(GO) test ./internal/one/ -bench=. > internal/one/benchmark
+	$(GO) test ./internal/two/ -bench=. > internal/two/benchmark
+	$(GO) test . -count=10 -bench=. > benchmark
+
+$(BIN_DIR):
+	@mkdir -p $@
+
+clean:
+	@rm -rv $(BIN_DIR)
diff --git a/day-22/solve.go b/day-22/solve.go
new file mode 100644
index 0000000..1e78fca
--- /dev/null
+++ b/day-22/solve.go
@@ -0,0 +1,20 @@
+package daytwentytwo
+
+import (
+	"github.com/onyx-and-iris/aoc2024/day-22/internal/one"
+	"github.com/onyx-and-iris/aoc2024/day-22/internal/two"
+)
+
+func Solve(buf []byte) (int, int, error) {
+	answerOne, err := one.Solve(buf)
+	if err != nil {
+		return 0, 0, err
+	}
+
+	answerTwo, err := two.Solve(buf)
+	if err != nil {
+		return 0, 0, err
+	}
+
+	return answerOne, answerTwo, nil
+}
diff --git a/day-22/solve_internal_test.go b/day-22/solve_internal_test.go
new file mode 100644
index 0000000..b8bfd4b
--- /dev/null
+++ b/day-22/solve_internal_test.go
@@ -0,0 +1,15 @@
+package daytwentytwo
+
+import (
+	_ "embed"
+	"os"
+	"testing"
+)
+
+//go:embed testdata/input.txt
+var data []byte
+
+func BenchmarkSolve(b *testing.B) {
+	os.Stdout, _ = os.Open(os.DevNull)
+	Solve(data)
+}