diff --git a/go.mod b/go.mod
index 2d80106..fedeb7a 100644
--- a/go.mod
+++ b/go.mod
@@ -10,6 +10,7 @@ require (
 	github.com/dgrijalva/jwt-go v3.2.0+incompatible // indirect
 	github.com/dustin/go-humanize v1.0.0
 	github.com/go-co-op/gocron v1.9.0
+	github.com/go-ozzo/ozzo-validation/v4 v4.3.0
 	github.com/go-redis/redis/v8 v8.11.4
 	github.com/gorilla/mux v1.8.0
 	github.com/heroku/x v0.0.32
diff --git a/go.sum b/go.sum
index 9556f7d..a6898e4 100644
--- a/go.sum
+++ b/go.sum
@@ -55,6 +55,8 @@ github.com/armon/circbuf v0.0.0-20150827004946-bbbad097214e/go.mod h1:3U/XgcO3hC
 github.com/armon/go-metrics v0.0.0-20180917152333-f0300d1749da/go.mod h1:Q73ZrmVTwzkszR9V5SSuryQ31EELlFMUz1kKyl939pY=
 github.com/armon/go-proxyproto v0.0.0-20190211145416-68259f75880e/go.mod h1:QmP9hvJ91BbJmGVGSbutW19IC0Q9phDCLGaomwTJbgU=
 github.com/armon/go-radix v0.0.0-20180808171621-7fddfc383310/go.mod h1:ufUuZ+zHj4x4TnLV4JWEpy2hxWSpsRywHrMgIH9cCH8=
+github.com/asaskevich/govalidator v0.0.0-20200108200545-475eaeb16496 h1:zV3ejI06GQ59hwDQAvmK1qxOQGB3WuVTRoY0okPTAv0=
+github.com/asaskevich/govalidator v0.0.0-20200108200545-475eaeb16496/go.mod h1:oGkLhpf+kjZl6xBf758TQhh5XrAeiJv/7FRz/2spLIg=
 github.com/aws/aws-sdk-go v1.13.10/go.mod h1:ZRmQr0FajVIyZ4ZzBYKG5P3ZqPz9IHG41ZoMu1ADI3k=
 github.com/axiomhq/hyperloglog v0.0.0-20180317131949-fe9507de0228/go.mod h1:IOXAcuKIFq/mDyuQ4wyJuJ79XLMsmLM+5RdQ+vWrL7o=
 github.com/benbjohnson/clock v1.1.0/go.mod h1:J11/hYXuz8f4ySSvYwY0FKfm+ezbsZBKZxNJlLklBHA=
@@ -120,6 +122,8 @@ github.com/go-kit/log v0.1.0/go.mod h1:zbhenjAZHb184qTLMA9ZjW7ThYL0H2mk7Q6pNt4vb
 github.com/go-logfmt/logfmt v0.4.0/go.mod h1:3RMwSq7FuexP4Kalkev3ejPJsZTpXXBr9+V4qmtdjCk=
 github.com/go-logfmt/logfmt v0.5.0/go.mod h1:wCYkCAKZfumFQihp8CzCvQ3paCTfi41vtzG1KdI/P7A=
 github.com/go-ole/go-ole v1.2.1/go.mod h1:7FAglXiTm7HKlQRDeOQ6ZNUHidzCWXuZWq/1dTyBNF8=
+github.com/go-ozzo/ozzo-validation/v4 v4.3.0 h1:byhDUpfEwjsVQb1vBunvIjh2BHQ9ead57VkAEY4V+Es=
+github.com/go-ozzo/ozzo-validation/v4 v4.3.0/go.mod h1:2NKgrcHl3z6cJs+3Oo940FPRiTzuqKbvfrL2RxCj6Ew=
 github.com/go-redis/redis/v8 v8.3.2/go.mod h1:jszGxBCez8QA1HWSmQxJO9Y82kNibbUmeYhKWrBejTU=
 github.com/go-redis/redis/v8 v8.11.4 h1:kHoYkfZP6+pe04aFTnhDH6GDROa5yJdHJVNxV3F46Tg=
 github.com/go-redis/redis/v8 v8.11.4/go.mod h1:2Z2wHZXdQpCDXEGzqMockDpNyYvi2l4Pxt6RJr792+w=
diff --git a/internal/cmd/worker.go b/internal/cmd/worker.go
index beb1b55..907e3f8 100644
--- a/internal/cmd/worker.go
+++ b/internal/cmd/worker.go
@@ -35,7 +35,8 @@ func WorkerCmd(ctx context.Context) *cobra.Command {
 
 			logger := cmdutil.NewLogrusLogger(false)
 
-			statsd, err := cmdutil.NewStatsdClient()
+			tag := fmt.Sprintf("worker:%s", queueID)
+			statsd, err := cmdutil.NewStatsdClient(tag)
 			if err != nil {
 				return err
 			}
diff --git a/internal/domain/account.go b/internal/domain/account.go
index bf74b98..5aef7bb 100644
--- a/internal/domain/account.go
+++ b/internal/domain/account.go
@@ -3,6 +3,8 @@ package domain
 import (
 	"context"
 	"strings"
+
+	validation "github.com/go-ozzo/ozzo-validation/v4"
 )
 
 // Account represents an account we need to periodically check in the notifications worker.
@@ -25,6 +27,13 @@ func (acct *Account) NormalizedUsername() string {
 	return strings.ToLower(acct.Username)
 }
 
+func (acct *Account) Validate() error {
+	return validation.ValidateStruct(acct,
+		validation.Field(&acct.Username, validation.Required, validation.Length(3, 32)),
+		validation.Field(&acct.AccountID, validation.Required, validation.Length(5, 7)),
+	)
+}
+
 // AccountRepository represents the account's repository contract
 type AccountRepository interface {
 	GetByID(ctx context.Context, id int64) (Account, error)
diff --git a/internal/domain/device.go b/internal/domain/device.go
index d7fbc74..d7f2e11 100644
--- a/internal/domain/device.go
+++ b/internal/domain/device.go
@@ -1,6 +1,10 @@
 package domain
 
-import "context"
+import (
+	"context"
+
+	validation "github.com/go-ozzo/ozzo-validation/v4"
+)
 
 const (
 	DeviceGracePeriodDuration            = 3600          // 1 hour
@@ -14,6 +18,12 @@ type Device struct {
 	ActiveUntil int64
 }
 
+func (dev *Device) Validate() error {
+	return validation.ValidateStruct(dev,
+		validation.Field(&dev.APNSToken, validation.Required, validation.Length(64, 200)),
+	)
+}
+
 type DeviceRepository interface {
 	GetByID(ctx context.Context, id int64) (Device, error)
 	GetByAPNSToken(ctx context.Context, token string) (Device, error)
diff --git a/internal/domain/subreddit.go b/internal/domain/subreddit.go
index 4563f22..fd0fd8e 100644
--- a/internal/domain/subreddit.go
+++ b/internal/domain/subreddit.go
@@ -3,6 +3,8 @@ package domain
 import (
 	"context"
 	"strings"
+
+	validation "github.com/go-ozzo/ozzo-validation/v4"
 )
 
 type Subreddit struct {
@@ -18,6 +20,13 @@ func (sr *Subreddit) NormalizedName() string {
 	return strings.ToLower(sr.Name)
 }
 
+func (sr *Subreddit) Validate() error {
+	return validation.ValidateStruct(sr,
+		validation.Field(&sr.Name, validation.Required, validation.Length(3, 32)),
+		validation.Field(&sr.SubredditID, validation.Required, validation.Length(5, 7)),
+	)
+}
+
 type SubredditRepository interface {
 	GetByID(ctx context.Context, id int64) (Subreddit, error)
 	GetByName(ctx context.Context, name string) (Subreddit, error)
diff --git a/internal/domain/user.go b/internal/domain/user.go
index 44dabc0..f855640 100644
--- a/internal/domain/user.go
+++ b/internal/domain/user.go
@@ -3,6 +3,8 @@ package domain
 import (
 	"context"
 	"strings"
+
+	validation "github.com/go-ozzo/ozzo-validation/v4"
 )
 
 type User struct {
@@ -18,6 +20,13 @@ func (u *User) NormalizedName() string {
 	return strings.ToLower(u.Name)
 }
 
+func (u *User) Validate() error {
+	return validation.ValidateStruct(u,
+		validation.Field(&u.Name, validation.Required, validation.Length(3, 32)),
+		validation.Field(&u.UserID, validation.Required, validation.Length(5, 7)),
+	)
+}
+
 type UserRepository interface {
 	GetByID(context.Context, int64) (User, error)
 	GetByName(context.Context, string) (User, error)
diff --git a/internal/repository/postgres_device.go b/internal/repository/postgres_device.go
index 14eb75b..5f3252e 100644
--- a/internal/repository/postgres_device.go
+++ b/internal/repository/postgres_device.go
@@ -102,6 +102,10 @@ func (p *postgresDeviceRepository) CreateOrUpdate(ctx context.Context, dev *doma
 }
 
 func (p *postgresDeviceRepository) Create(ctx context.Context, dev *domain.Device) error {
+	if err := dev.Validate(); err != nil {
+		return err
+	}
+
 	query := `
 		INSERT INTO devices
 			(apns_token, sandbox, active_until)
@@ -118,6 +122,10 @@ func (p *postgresDeviceRepository) Create(ctx context.Context, dev *domain.Devic
 }
 
 func (p *postgresDeviceRepository) Update(ctx context.Context, dev *domain.Device) error {
+	if err := dev.Validate(); err != nil {
+		return err
+	}
+
 	query := `
 		UPDATE devices
 		SET active_until = $2
diff --git a/internal/repository/postgres_subreddit.go b/internal/repository/postgres_subreddit.go
index 3a7e88e..663f92e 100644
--- a/internal/repository/postgres_subreddit.go
+++ b/internal/repository/postgres_subreddit.go
@@ -76,6 +76,10 @@ func (p *postgresSubredditRepository) GetByName(ctx context.Context, name string
 }
 
 func (p *postgresSubredditRepository) CreateOrUpdate(ctx context.Context, sr *domain.Subreddit) error {
+	if err := sr.Validate(); err != nil {
+		return err
+	}
+
 	query := `
 		INSERT INTO subreddits (subreddit_id, name)
 		VALUES ($1, $2)
diff --git a/internal/repository/postgres_user.go b/internal/repository/postgres_user.go
index 5f038ad..fdf9eab 100644
--- a/internal/repository/postgres_user.go
+++ b/internal/repository/postgres_user.go
@@ -5,8 +5,9 @@ import (
 	"fmt"
 	"strings"
 
-	"github.com/christianselig/apollo-backend/internal/domain"
 	"github.com/jackc/pgx/v4/pgxpool"
+
+	"github.com/christianselig/apollo-backend/internal/domain"
 )
 
 type postgresUserRepository struct {
@@ -77,6 +78,10 @@ func (p *postgresUserRepository) GetByName(ctx context.Context, name string) (do
 }
 
 func (p *postgresUserRepository) CreateOrUpdate(ctx context.Context, u *domain.User) error {
+	if err := u.Validate(); err != nil {
+		return err
+	}
+
 	query := `
 		INSERT INTO users (user_id, name)
 		VALUES ($1, $2)