diff --git a/api/auth.go b/api/auth.go
index 727ceada..af20e471 100644
--- a/api/auth.go
+++ b/api/auth.go
@@ -83,9 +83,9 @@ func NewAuth(key *ecdsa.PrivateKey, customers customers.Repository, passwd strin
 // CreateCustomerJWT creates a JWT that only stores the customer ID.
 func (auth *Auth) CreateCustomerJWT(customerId int) ([]byte, error) {
 	t := openid.New()
-	t.Set(jwt.IssuedAtKey, time.Now())
-	t.Set(jwt.ExpirationKey, time.Now().Add(MaxSessionAge))
-	t.Set(CustomerID, customerId)
+	_ = t.Set(jwt.IssuedAtKey, time.Now())
+	_ = t.Set(jwt.ExpirationKey, time.Now().Add(MaxSessionAge))
+	_ = t.Set(CustomerID, customerId)
 
 	return jwt.Sign(t, jwa.ES256, auth.sessionKey)
 }
diff --git a/api/transfer.go b/api/transfer.go
index 22c5c432..509250db 100644
--- a/api/transfer.go
+++ b/api/transfer.go
@@ -1,7 +1,6 @@
 package api
 
 import (
-	"context"
 	"errors"
 	"fmt"
 	"net/http"
@@ -96,6 +95,9 @@ func (w Wrapper) UpdateTransfer(ctx echo.Context, transferID string) error {
 		t.TransferDate = updateRequest.TransferDate
 		return t, nil
 	})
+	if err != nil {
+		return err
+	}
 
 	transfer, err := w.TransferSenderService.GetTransferByID(ctx.Request().Context(), cid, transferID)
 	if err != nil {
@@ -258,16 +260,3 @@ func (w Wrapper) NotifyTransferUpdate(ctx echo.Context, taskID string) error {
 
 	return ctx.NoContent(http.StatusAccepted)
 }
-
-func (w Wrapper) findNegotiation(ctx context.Context, customerID int, transferID, negotiationID string) (*types.TransferNegotiation, error) {
-	negotiations, err := w.TransferSenderRepo.ListNegotiations(ctx, customerID, transferID)
-	if err != nil {
-		return nil, err
-	}
-	for _, curr := range negotiations {
-		if string(curr.Id) == negotiationID {
-			return &curr, nil
-		}
-	}
-	return nil, errors.New("transfer negotiation not found")
-}
diff --git a/config.go b/config.go
index 5d0e22a4..24fb2f22 100644
--- a/config.go
+++ b/config.go
@@ -167,7 +167,9 @@ func generateSessionKey() (*ecdsa.PrivateKey, error) {
 		return nil, err
 	}
 	block := pem.Block{Type: "EC PRIVATE KEY", Bytes: keyBytes}
-	pem.Encode(log.Writer(), &block)
+	if err := pem.Encode(log.Writer(), &block); err != nil {
+		return nil, err
+	}
 
 	return key, nil
 }
diff --git a/domain/customers/repository.go b/domain/customers/repository.go
index 715bc8b6..7664d321 100644
--- a/domain/customers/repository.go
+++ b/domain/customers/repository.go
@@ -19,13 +19,14 @@ type jsonFileRepo struct {
 	filepath string
 }
 
-func NewJsonFileRepository(filepath string) *jsonFileRepo {
+func NewJsonFileRepository(filepath string) Repository {
 	f, err := os.OpenFile(filepath, os.O_RDONLY, 0666)
-	defer f.Close()
 	if err != nil {
 		log.Warnf("Could not open cusomers file (path=%s), it still needs to be created: %s", filepath, err)
 		// But allow to proceed, since it is shared with nuts-registry-admin-demo, which creates it.
 		// In Docker environments, it might not be there yet if demo-ehr starts first.
+	} else {
+		defer f.Close()
 	}
 
 	return &jsonFileRepo{
diff --git a/domain/episode/service.go b/domain/episode/service.go
index 825ecb71..61932f1e 100644
--- a/domain/episode/service.go
+++ b/domain/episode/service.go
@@ -5,7 +5,6 @@ import (
 	"errors"
 	"fmt"
 	"github.com/nuts-foundation/nuts-demo-ehr/domain/acl"
-	nutsClient "github.com/nuts-foundation/nuts-demo-ehr/nuts/client"
 	"github.com/sirupsen/logrus"
 	"net/url"
 	"strings"
@@ -46,7 +45,6 @@ type service struct {
 	factory       fhir.Factory
 	auth          auth.Service
 	aclRepository *acl.Repository
-	nutsClient    nutsClient.HTTPClient
 	registry      registry.OrganizationRegistry
 	vcr           registry.VerifiableCredentialRegistry
 }
@@ -166,7 +164,7 @@ func (service *service) GetCollaborations(ctx context.Context, customerDID, doss
 
 	var collaborations []types.Collaboration
 
-	for authorizedDID, _ := range authorizedDIDs {
+	for authorizedDID := range authorizedDIDs {
 		org, err := service.registry.Get(ctx, authorizedDID)
 		if err != nil {
 			logrus.WithError(err).Warn("Error looking up episode collaborator organization")
diff --git a/domain/fhir/client.go b/domain/fhir/client.go
index 51e9b251..29ea9223 100644
--- a/domain/fhir/client.go
+++ b/domain/fhir/client.go
@@ -74,7 +74,6 @@ type httpClient struct {
 	url                 string
 	tenant              int
 	multiTenancyEnabled bool
-	tlsConfig           *tls.Config
 }
 
 func (h httpClient) Create(ctx context.Context, resource interface{}, result interface{}) error {
diff --git a/domain/fhir/util.go b/domain/fhir/util.go
index 853dd53f..f60c5e72 100644
--- a/domain/fhir/util.go
+++ b/domain/fhir/util.go
@@ -67,8 +67,3 @@ func ToIDPtr(str string) *datatypes.ID {
 	result := datatypes.ID(str)
 	return &result
 }
-
-func toCodePtr(str string) *datatypes.Code {
-	result := datatypes.Code(str)
-	return &result
-}
diff --git a/domain/reports/repository.go b/domain/reports/repository.go
index 79446de6..7f6f9a08 100644
--- a/domain/reports/repository.go
+++ b/domain/reports/repository.go
@@ -26,7 +26,7 @@ type fhirRepository struct {
 	factory fhir.Factory
 }
 
-func NewFHIRRepository(factory fhir.Factory) *fhirRepository {
+func NewFHIRRepository(factory fhir.Factory) Repository {
 	return &fhirRepository{
 		factory: factory,
 	}
diff --git a/http/auth/service.go b/http/auth/service.go
index 9c1324ab..edca4e29 100644
--- a/http/auth/service.go
+++ b/http/auth/service.go
@@ -30,14 +30,6 @@ type authService struct {
 	client *nutsAuthClient.ClientWithResponses
 }
 
-func fromStringPtr(ptr *string) (output string) {
-	if ptr != nil {
-		output = *ptr
-	}
-
-	return
-}
-
 func NewService(server string) (Service, error) {
 	authClient, err := nutsAuthClient.NewClientWithResponses(server)
 	if err != nil {
diff --git a/main.go b/main.go
index f003f829..90b35904 100644
--- a/main.go
+++ b/main.go
@@ -58,8 +58,6 @@ const assetPath = "web/dist"
 //go:embed web/dist/*
 var embeddedFiles embed.FS
 
-const apiTimeout = 10 * time.Second
-
 func getFileSystem(useFS bool) http.FileSystem {
 	if useFS {
 		logrus.Info("using live mode")
@@ -134,7 +132,7 @@ func createServer() *echo.Echo {
 	server.Logger.SetLevel(log2.DEBUG)
 	server.HTTPErrorHandler = func(err error, ctx echo.Context) {
 		if !ctx.Response().Committed {
-			ctx.Response().Write([]byte(err.Error()))
+			_, _ = ctx.Response().Write([]byte(err.Error()))
 			ctx.Echo().Logger.Error(err)
 		}
 	}
@@ -357,7 +355,7 @@ func httpErrorHandler(err error, c echo.Context) {
 		code = he.Code
 		msg = he.Message
 		if he.Internal != nil {
-			err = fmt.Errorf("%v, %v", err, he.Internal)
+			msg = fmt.Sprintf("%v, %v", err, he.Internal)
 		}
 	} else {
 		msg = err.Error()
@@ -410,7 +408,7 @@ func (cb *fhirBinder) Bind(i interface{}, c echo.Context) (err error) {
 	}
 
 	if strings.Contains(c.Request().Header.Get("Content-Type"), "application/fhir+json") {
-		var bytes = make([]byte, 0)
+		var bytes []byte
 		if bytes, err = io.ReadAll(c.Request().Body); err != nil {
 			return
 		}