diff --git a/cmd/go_migrate/build-extract-query.go b/cmd/go_migrate/build-extract-query.go
deleted file mode 100644
index 478a4a8..0000000
--- a/cmd/go_migrate/build-extract-query.go
+++ /dev/null
@@ -1,75 +0,0 @@
-package main
-
-import (
-	"fmt"
-	"strings"
-
-	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/config"
-)
-
-func buildExtractQueryMssql(sourceDbInfo config.SourceTableInfo, columns []ColumnType, includeRange bool, isMinInclusive bool) string {
-	var sbQuery strings.Builder
-
-	sbQuery.WriteString("SELECT ")
-
-	if len(columns) == 0 {
-		sbQuery.WriteString("*")
-	} else {
-		for i, col := range columns {
-			fmt.Fprintf(&sbQuery, "[%s]", col.name)
-
-			if col.unifiedType == "GEOMETRY" {
-				fmt.Fprintf(&sbQuery, ".STAsBinary() AS [%s]", col.name)
-			}
-
-			if i < len(columns)-1 {
-				sbQuery.WriteString(", ")
-			}
-		}
-	}
-
-	fmt.Fprintf(&sbQuery, " FROM [%s].[%s]", sourceDbInfo.Schema, sourceDbInfo.Table)
-
-	if includeRange {
-		fmt.Fprintf(&sbQuery, " WHERE [%s]", sourceDbInfo.PrimaryKey)
-		if isMinInclusive {
-			sbQuery.WriteString(" >=")
-		} else {
-			sbQuery.WriteString(" >")
-		}
-
-		fmt.Fprintf(&sbQuery, " @min AND [%s] <= @max", sourceDbInfo.PrimaryKey)
-	}
-
-	fmt.Fprintf(&sbQuery, " ORDER BY [%s] ASC", sourceDbInfo.PrimaryKey)
-
-	return sbQuery.String()
-}
-
-func buildExtractQueryPostgres(sourceDbInfo config.SourceTableInfo, columns []ColumnType) string {
-	var sbColumns strings.Builder
-
-	if len(columns) == 0 {
-		sbColumns.WriteString("*")
-	} else {
-		for i, col := range columns {
-			if col.unifiedType == "GEOMETRY" {
-				sbColumns.WriteString(`ST_AsEWKB("`)
-				sbColumns.WriteString(col.name)
-				sbColumns.WriteString(`") AS "`)
-				sbColumns.WriteString(col.name)
-				sbColumns.WriteString(`"`)
-			} else {
-				sbColumns.WriteString(`"`)
-				sbColumns.WriteString(col.name)
-				sbColumns.WriteString(`"`)
-			}
-
-			if i < len(columns)-1 {
-				sbColumns.WriteString(", ")
-			}
-		}
-	}
-
-	return fmt.Sprintf(`SELECT %s FROM "%s"."%s"  ORDER BY "%s" ASC`, sbColumns.String(), sourceDbInfo.Schema, sourceDbInfo.Table, sourceDbInfo.PrimaryKey)
-}
diff --git a/cmd/go_migrate/job-error-handler.go b/cmd/go_migrate/job-error-handler.go
deleted file mode 100644
index 4fc89ff..0000000
--- a/cmd/go_migrate/job-error-handler.go
+++ /dev/null
@@ -1,47 +0,0 @@
-package main
-
-import (
-	"context"
-	"fmt"
-
-	log "github.com/sirupsen/logrus"
-)
-
-type JobError struct {
-	ShouldCancelJob bool
-	Msg             string
-	Prev            error
-}
-
-func (e *JobError) Error() string {
-	if e.Prev != nil {
-		return fmt.Sprintf("%s: %v", e.Msg, e.Prev)
-	}
-
-	return e.Msg
-}
-
-func jobErrorHandler(ctx context.Context, chErrorsIn <-chan JobError) error {
-	for {
-		if ctx.Err() != nil {
-			return nil
-		}
-
-		select {
-		case <-ctx.Done():
-			return nil
-
-		case err, ok := <-chErrorsIn:
-			if !ok {
-				return nil
-			}
-
-			if err.ShouldCancelJob {
-				log.Error(err.Msg, " - ", err.Prev)
-				return &err
-			}
-
-			log.Error(err.Msg, " - ", err.Prev)
-		}
-	}
-}
diff --git a/cmd/go_migrate/loader.go b/cmd/go_migrate/loader.go
index 70faa5e..54a9957 100644
--- a/cmd/go_migrate/loader.go
+++ b/cmd/go_migrate/loader.go
@@ -25,7 +25,7 @@ func loadRowsPostgres(
 	tableInfo config.TargetTableInfo,
 	columns []models.ColumnType,
 	chChunksIn <-chan models.Chunk,
-	chErrorsOut chan<- LoaderError,
+	chErrorsOut chan<- custom_errors.LoaderError,
 	chJobErrorsOut chan<- custom_errors.JobError,
 	wgActiveChunks *sync.WaitGroup,
 	rowsLoaded *int64,
@@ -61,7 +61,7 @@ func loadChunkPostgres(
 	identifier pgx.Identifier,
 	colNames []string,
 	chunk models.Chunk,
-	chErrorsOut chan<- LoaderError,
+	chErrorsOut chan<- custom_errors.LoaderError,
 	chJobErrorsOut chan<- custom_errors.JobError,
 	wgActiveChunks *sync.WaitGroup,
 	rowsLoaded *int64,
@@ -92,7 +92,7 @@ func loadChunkPostgres(
 		}
 
 		select {
-		case chErrorsOut <- LoaderError{Chunk: chunk, Msg: err.Error()}:
+		case chErrorsOut <- custom_errors.LoaderError{Chunk: chunk, Msg: err.Error()}:
 		case <-ctx.Done():
 			return true
 		}
diff --git a/cmd/go_migrate/process.go b/cmd/go_migrate/process.go
index c5c7513..0a7b800 100644
--- a/cmd/go_migrate/process.go
+++ b/cmd/go_migrate/process.go
@@ -52,7 +52,7 @@ func processMigrationJob(
 	chExtractorErrors := make(chan custom_errors.ExtractorError, job.QueueSize)
 	chChunksRaw := make(chan models.Chunk, job.QueueSize)
 	chChunksTransformed := make(chan models.Chunk, job.QueueSize)
-	chLoadersErrors := make(chan LoaderError, job.QueueSize)
+	chLoadersErrors := make(chan custom_errors.LoaderError, job.QueueSize)
 
 	var wgActiveBatches sync.WaitGroup
 	var wgActiveChunks sync.WaitGroup
@@ -68,7 +68,7 @@ func processMigrationJob(
 	}()
 
 	go custom_errors.ExtractorErrorHandler(jobCtx, job.Retry.Attempts, chExtractorErrors, chBatches, chJobErrors, &wgActiveBatches)
-	go loaderErrorHandler(jobCtx, job.Retry.Attempts, chLoadersErrors, chChunksTransformed, chJobErrors, &wgActiveChunks)
+	go custom_errors.LoaderErrorHandler(jobCtx, job.Retry.Attempts, chLoadersErrors, chChunksTransformed, chJobErrors, &wgActiveChunks)
 
 	maxExtractors := min(job.MaxExtractors, len(batches))
 	log.Infof("Starting %d extractor(s)...", maxExtractors)
diff --git a/cmd/go_migrate/loader-error-handler.go b/internal/app/custom_errors/loader.error.go
similarity index 83%
rename from cmd/go_migrate/loader-error-handler.go
rename to internal/app/custom_errors/loader.error.go
index edd3569..3114b67 100644
--- a/cmd/go_migrate/loader-error-handler.go
+++ b/internal/app/custom_errors/loader.error.go
@@ -1,11 +1,10 @@
-package main
+package custom_errors
 
 import (
 	"context"
 	"fmt"
 	"sync"
 
-	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/custom_errors"
 	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/models"
 )
 
@@ -18,12 +17,12 @@ func (e *LoaderError) Error() string {
 	return e.Msg
 }
 
-func loaderErrorHandler(
+func LoaderErrorHandler(
 	ctx context.Context,
 	maxRetryAttempts int,
 	chErrorsIn <-chan LoaderError,
 	chChunksOut chan<- models.Chunk,
-	chJobErrorsOut chan<- custom_errors.JobError,
+	chJobErrorsOut chan<- JobError,
 	wgActiveChunks *sync.WaitGroup,
 ) {
 	for {
@@ -41,7 +40,7 @@ func loaderErrorHandler(
 			}
 
 			if err.RetryCounter >= maxRetryAttempts {
-				jobError := custom_errors.JobError{
+				jobError := JobError{
 					ShouldCancelJob: false,
 					Msg:             fmt.Sprintf("chunk %v reached max retries (%d)", err.Id, maxRetryAttempts),
 					Prev:            &err,