diff --git a/internal/runner/go.go b/internal/runner/go.go
new file mode 100644
index 00000000..fbacb1af
--- /dev/null
+++ b/internal/runner/go.go
@@ -0,0 +1,17 @@
+package runner
+
+import "github.com/buildkite/test-splitter/internal/api"
+
+type GoTests struct{}
+
+func (GoTests) FindFiles() ([]string, error) {
+	return nil, nil
+}
+
+func (GoTests) Run(testCases []string) error {
+	return nil
+}
+
+func (GoTests) Report([]api.TestCase) {
+
+}
diff --git a/internal/runner/rspec.go b/internal/runner/rspec.go
index afb12a1a..68b577cb 100644
--- a/internal/runner/rspec.go
+++ b/internal/runner/rspec.go
@@ -1,22 +1,22 @@
 package runner
 
 import (
+	"errors"
 	"fmt"
-	"log"
 	"math"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"strings"
+	"syscall"
 	"time"
 
 	"github.com/buildkite/test-splitter/internal/api"
 )
 
-type Rspec struct {
-}
+type Rspec struct{}
 
-func (Rspec) GetFiles() []string {
+func (Rspec) FindFiles() ([]string, error) {
 	var files []string
 
 	// Use filepath.Walk to traverse the directory recursively
@@ -34,24 +34,39 @@ func (Rspec) GetFiles() []string {
 
 	// Handle potential error from filepath.Walk
 	if err != nil {
-		log.Fatal("Error when getting files: ", err)
+		return nil, fmt.Errorf("walking to find files: %w", err)
 	}
 
-	return files
+	return files, nil
 }
 
-func (Rspec) Run(testCases []string) error {
+func (r Rspec) Run(testCases []string) error {
 	args := []string{"--options", ".rspec.ci"}
 
 	args = append(args, testCases...)
 
+	// TODO: Figure out in advance whether we'll hit ARG_MAX and make args
+	// an appropriate size
+
 	fmt.Println("+++ :test-analytics: Executing tests 🏃")
 	fmt.Println("bin/rspec", strings.Join(args, " "))
 
 	cmd := exec.Command("bin/rspec", args...)
 	cmd.Stderr = os.Stderr
 	cmd.Stdout = os.Stdout
-	return cmd.Run()
+
+	err := cmd.Run()
+	if errors.Is(err, syscall.E2BIG) { // Will this work on e.g. Windows?
+		n := len(testCases) / 2
+		if err := r.Run(testCases[:n]); err != nil {
+			return err
+		}
+		if err := r.Run(testCases[n:]); err != nil {
+			return err
+		}
+		return nil
+	}
+	return err
 }
 
 type RspecExample struct {
diff --git a/main.go b/main.go
index 0800bd1c..b5061721 100644
--- a/main.go
+++ b/main.go
@@ -4,6 +4,7 @@ package main
 
 import (
 	"encoding/json"
+	"flag"
 	"fmt"
 	"log"
 
@@ -22,12 +23,32 @@ type RspecData struct {
 }
 
 func main() {
-	// TODO: detect test runner and use appropriate runner
-	testRunner := runner.Rspec{}
+	testType := flag.String("type", "rspec", "Test `framework` to be run [rspec, go]")
+	flag.Parse()
+
+	var testRunner interface {
+		FindFiles() ([]string, error)
+		Run([]string) error
+		Report([]api.TestCase)
+	}
+
+	switch *testType {
+	case "rspec":
+		testRunner = runner.Rspec{}
+
+	case "go":
+		testRunner = runner.GoTests{}
+
+	default:
+		log.Fatalf("Unsupported test type %q", *testType)
+	}
 
 	// get files
 	fmt.Println("--- :test-analytics: Gathering test plan context and creating test plan request 🐿️")
-	files := testRunner.GetFiles()
+	files, err := testRunner.FindFiles()
+	if err != nil {
+		log.Fatalf("Couldn't find test files: %v", err)
+	}
 	fmt.Printf("Found %d files\n", len(files))
 
 	// fetch env vars