diff --git a/Makefile b/Makefile
index fae6bed..39384e1 100644
--- a/Makefile
+++ b/Makefile
@@ -34,7 +34,7 @@ web: web-all
 
 .PHONY: build
 build: tidy sqlc # build.
-	@go build -v -ldflags "$(GO_LDFLAGS)" -o $(OUTPUT_DIR)/howmuch $(ROOT_DIR)/cmd/howmuch/main.go 2>/dev/null
+	@go build -v -ldflags "$(GO_LDFLAGS)" -o $(OUTPUT_DIR)/howmuch $(ROOT_DIR)/cmd/howmuch/main.go
 
 .PHONY: sqlc
 sqlc:
diff --git a/configs/howmuch.yml b/configs/howmuch.yml
index 45abff2..17f7dd5 100644
--- a/configs/howmuch.yml
+++ b/configs/howmuch.yml
@@ -16,6 +16,10 @@ db:
   # DB name
   database: howmuch
 
+  max-open-conns: 100
+  max-idle-conns: 100
+  max-lifetime: 10s
+
 cache:
   host: 127.0.0.1:6379
   password: ""
diff --git a/go.mod b/go.mod
index dd6d615..d97b4d7 100644
--- a/go.mod
+++ b/go.mod
@@ -41,6 +41,7 @@ require (
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/jackc/pgpassfile v1.0.0 // indirect
 	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
+	github.com/jackc/puddle/v2 v2.2.2 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
 	github.com/klauspost/cpuid/v2 v2.2.7 // indirect
 	github.com/leodido/go-urn v1.4.0 // indirect
@@ -65,6 +66,7 @@ require (
 	go.uber.org/multierr v1.11.0 // indirect
 	golang.org/x/arch v0.8.0 // indirect
 	golang.org/x/exp v0.0.0-20230905200255-921286631fa9 // indirect
+	golang.org/x/sync v0.8.0 // indirect
 	golang.org/x/sys v0.25.0 // indirect
 	golang.org/x/text v0.18.0 // indirect
 	google.golang.org/protobuf v1.34.1 // indirect
diff --git a/internal/howmuch/adapter/repo/db.go b/internal/howmuch/adapter/repo/db.go
index 8214510..e1db2f7 100644
--- a/internal/howmuch/adapter/repo/db.go
+++ b/internal/howmuch/adapter/repo/db.go
@@ -24,17 +24,17 @@ package repo
 
 import (
 	"context"
+	"database/sql"
 
 	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/usecase/repo"
 	"git.vinchent.xyz/vinchent/howmuch/internal/pkg/log"
-	"github.com/jackc/pgx/v5"
 )
 
 type dbRepository struct {
-	db *pgx.Conn
+	db *sql.DB
 }
 
-func NewDBRepository(db *pgx.Conn) repo.DBRepository {
+func NewDBRepository(db *sql.DB) repo.DBRepository {
 	return &dbRepository{
 		db: db,
 	}
@@ -46,20 +46,20 @@ func (dr *dbRepository) Transaction(
 	ctx context.Context,
 	txFunc func(txCtx context.Context, tx interface{}) (interface{}, error),
 ) (interface{}, error) {
-	tx, err := dr.db.Begin(ctx)
+	tx, err := dr.db.BeginTx(ctx, nil)
 	if err != nil {
 		return nil, err
 	}
 
 	defer func() {
 		if p := recover(); p != nil {
-			tx.Rollback(ctx)
+			tx.Rollback()
 			log.PanicLog("transaction panicked!")
 		} else if err != nil {
-			tx.Rollback(ctx)
+			tx.Rollback()
 			log.ErrorLog("transaction failed!", "err", err)
 		} else {
-			err = tx.Commit(ctx)
+			err = tx.Commit()
 		}
 	}()
 
diff --git a/internal/howmuch/adapter/repo/sqlc/db.go b/internal/howmuch/adapter/repo/sqlc/db.go
index b931bc5..2248616 100644
--- a/internal/howmuch/adapter/repo/sqlc/db.go
+++ b/internal/howmuch/adapter/repo/sqlc/db.go
@@ -6,15 +6,14 @@ package sqlc
 
 import (
 	"context"
-
-	"github.com/jackc/pgx/v5"
-	"github.com/jackc/pgx/v5/pgconn"
+	"database/sql"
 )
 
 type DBTX interface {
-	Exec(context.Context, string, ...interface{}) (pgconn.CommandTag, error)
-	Query(context.Context, string, ...interface{}) (pgx.Rows, error)
-	QueryRow(context.Context, string, ...interface{}) pgx.Row
+	ExecContext(context.Context, string, ...interface{}) (sql.Result, error)
+	PrepareContext(context.Context, string) (*sql.Stmt, error)
+	QueryContext(context.Context, string, ...interface{}) (*sql.Rows, error)
+	QueryRowContext(context.Context, string, ...interface{}) *sql.Row
 }
 
 func New(db DBTX) *Queries {
@@ -25,7 +24,7 @@ type Queries struct {
 	db DBTX
 }
 
-func (q *Queries) WithTx(tx pgx.Tx) *Queries {
+func (q *Queries) WithTx(tx *sql.Tx) *Queries {
 	return &Queries{
 		db: tx,
 	}
diff --git a/internal/howmuch/adapter/repo/sqlc/models.go b/internal/howmuch/adapter/repo/sqlc/models.go
index d00eeb2..7913d60 100644
--- a/internal/howmuch/adapter/repo/sqlc/models.go
+++ b/internal/howmuch/adapter/repo/sqlc/models.go
@@ -5,7 +5,7 @@
 package sqlc
 
 import (
-	"github.com/jackc/pgx/v5/pgtype"
+	"time"
 )
 
 type Admin struct {
@@ -21,6 +21,6 @@ type User struct {
 	FirstName string
 	LastName  string
 	Password  string
-	CreatedAt pgtype.Timestamp
-	UpdatedAt pgtype.Timestamp
+	CreatedAt time.Time
+	UpdatedAt time.Time
 }
diff --git a/internal/howmuch/adapter/repo/sqlc/user.sql.go b/internal/howmuch/adapter/repo/sqlc/user.sql.go
index 6e9a1da..43837d9 100644
--- a/internal/howmuch/adapter/repo/sqlc/user.sql.go
+++ b/internal/howmuch/adapter/repo/sqlc/user.sql.go
@@ -7,8 +7,7 @@ package sqlc
 
 import (
 	"context"
-
-	"github.com/jackc/pgx/v5/pgtype"
+	"time"
 )
 
 const getUserByEmail = `-- name: GetUserByEmail :one
@@ -18,7 +17,7 @@ SELECT id, email, first_name, last_name, password, created_at, updated_at
 `
 
 func (q *Queries) GetUserByEmail(ctx context.Context, email string) (User, error) {
-	row := q.db.QueryRow(ctx, getUserByEmail, email)
+	row := q.db.QueryRowContext(ctx, getUserByEmail, email)
 	var i User
 	err := row.Scan(
 		&i.ID,
@@ -45,8 +44,8 @@ type InsertUserParams struct {
 	FirstName string
 	LastName  string
 	Password  string
-	CreatedAt pgtype.Timestamp
-	UpdatedAt pgtype.Timestamp
+	CreatedAt time.Time
+	UpdatedAt time.Time
 }
 
 // MIT License
@@ -71,7 +70,7 @@ type InsertUserParams struct {
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 // SOFTWARE.
 func (q *Queries) InsertUser(ctx context.Context, arg InsertUserParams) (User, error) {
-	row := q.db.QueryRow(ctx, insertUser,
+	row := q.db.QueryRowContext(ctx, insertUser,
 		arg.Email,
 		arg.FirstName,
 		arg.LastName,
diff --git a/internal/howmuch/adapter/repo/user.go b/internal/howmuch/adapter/repo/user.go
index a273ced..97814da 100644
--- a/internal/howmuch/adapter/repo/user.go
+++ b/internal/howmuch/adapter/repo/user.go
@@ -24,6 +24,7 @@ package repo
 
 import (
 	"context"
+	"database/sql"
 	"errors"
 	"time"
 
@@ -31,16 +32,15 @@ import (
 	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/model"
 	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/usecase/repo"
 	"github.com/jackc/pgx/v5"
-	"github.com/jackc/pgx/v5/pgtype"
 )
 
 type userRepository struct {
-	db *pgx.Conn
+	db *sql.DB
 }
 
 const insertTimeout = 1 * time.Second
 
-func NewUserRepository(db *pgx.Conn) repo.UserRepository {
+func NewUserRepository(db *sql.DB) repo.UserRepository {
 	return &userRepository{
 		db: db,
 	}
@@ -60,11 +60,11 @@ func (ur *userRepository) Create(
 		FirstName: u.FirstName,
 		LastName:  u.LastName,
 		Password:  u.Password,
-		CreatedAt: pgtype.Timestamp{Time: time.Now(), Valid: true},
-		UpdatedAt: pgtype.Timestamp{Time: time.Now(), Valid: true},
+		CreatedAt: time.Now(),
+		UpdatedAt: time.Now(),
 	}
 
-	tx, ok := transaction.(pgx.Tx)
+	tx, ok := transaction.(*sql.Tx)
 	if !ok {
 		return nil, errors.New("transaction is not a pgx.Tx")
 	}
@@ -82,8 +82,8 @@ func (ur *userRepository) Create(
 		FirstName: userDB.FirstName,
 		LastName:  userDB.LastName,
 		Password:  userDB.Password,
-		CreatedAt: userDB.CreatedAt.Time,
-		UpdatedAt: userDB.CreatedAt.Time,
+		CreatedAt: userDB.CreatedAt,
+		UpdatedAt: userDB.CreatedAt,
 	}, nil
 }
 
@@ -104,7 +104,7 @@ func (ur *userRepository) GetByEmail(ctx context.Context, email string) (*model.
 		FirstName: userDB.FirstName,
 		LastName:  userDB.LastName,
 		Password:  userDB.Password,
-		CreatedAt: userDB.CreatedAt.Time,
-		UpdatedAt: userDB.CreatedAt.Time,
+		CreatedAt: userDB.CreatedAt,
+		UpdatedAt: userDB.CreatedAt,
 	}, nil
 }
diff --git a/internal/howmuch/howmuch.go b/internal/howmuch/howmuch.go
index e4d6a86..9e93735 100644
--- a/internal/howmuch/howmuch.go
+++ b/internal/howmuch/howmuch.go
@@ -38,7 +38,6 @@ import (
 	"git.vinchent.xyz/vinchent/howmuch/internal/pkg/token"
 	"git.vinchent.xyz/vinchent/howmuch/pkg/version/verflag"
 	"github.com/gin-gonic/gin"
-	"github.com/jackc/pgx/v5"
 	"github.com/redis/go-redis/v9"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
@@ -117,15 +116,17 @@ func run() error {
 		viper.GetString("db.password"),
 		viper.GetString("db.sslmode"),
 	)
-	dbConf, err := pgx.ParseConfig(dbConfString)
-	if err != nil {
-		log.FatalLog("DB connection config failure", "err", err, "cfg string", dbConfString)
+	// TODO: viper conf should be parsed into a struct directly
+	dbExtraConf := &datastore.DbExtraConf{
+		MaxOpenConns: viper.GetInt("db.max-open-conns"),
+		MaxIdleConns: viper.GetInt("db.max-idle-conns"),
+		MaxLifetime:  viper.GetDuration("db.max-lifetime"),
 	}
-	dbConn, err := datastore.NewDB(dbConf)
-	if err != nil {
-		log.FatalLog("DB connection failure", "err", err)
+	dbConn := datastore.NewDB(dbConfString, dbExtraConf)
+	if dbConn == nil {
+		log.FatalLog("DB connection failure")
 	}
-	defer dbConn.Close(context.Background())
+	defer dbConn.Close()
 
 	// Init Cache
 	cache := datastore.NewCache(&redis.Options{
diff --git a/internal/howmuch/infra/datastore/db.go b/internal/howmuch/infra/datastore/db.go
index 8141785..d3fc37c 100644
--- a/internal/howmuch/infra/datastore/db.go
+++ b/internal/howmuch/infra/datastore/db.go
@@ -23,22 +23,65 @@
 package datastore
 
 import (
-	"context"
+	"database/sql"
+	"time"
 
-	"github.com/jackc/pgx/v5"
+	"git.vinchent.xyz/vinchent/howmuch/internal/pkg/log"
+	_ "github.com/jackc/pgx/v5"
+	_ "github.com/jackc/pgx/v5/stdlib"
 )
 
+var counts int
+
+type DbExtraConf struct {
+	MaxOpenConns int
+	MaxIdleConns int
+	MaxLifetime  time.Duration
+}
+
 // NewDB creates a new database for the application
-func NewDB(connConfig *pgx.ConnConfig) (*pgx.Conn, error) {
-	conn, err := pgx.ConnectConfig(context.Background(), connConfig)
+func NewDB(dsn string, opts interface{}) *sql.DB {
+	var db *sql.DB
+	var err error
+
+	for {
+		db, err = openDB(dsn)
+		if err != nil {
+			log.WarnLog("postgres not ready", "err", err)
+			counts++
+		} else {
+			log.InfoLog("connected to postgres")
+			break
+		}
+
+		if counts > 10 {
+			break
+		}
+		log.InfoLog("retry in 2 seconds")
+		time.Sleep(2 * time.Second)
+	}
+
+	if db == nil {
+		return nil
+	}
+
+	extraConf, ok := opts.(DbExtraConf)
+	if ok {
+		db.SetMaxOpenConns(extraConf.MaxOpenConns)
+		db.SetMaxIdleConns(extraConf.MaxIdleConns)
+		db.SetConnMaxLifetime(extraConf.MaxLifetime)
+	}
+	return db
+}
+
+func openDB(dsn string) (*sql.DB, error) {
+	db, err := sql.Open("pgx", dsn)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ping test the conn
-	if err = conn.Ping(context.Background()); err != nil {
+	if err := db.Ping(); err != nil {
 		return nil, err
 	}
-
-	return conn, err
+	return db, nil
 }
diff --git a/internal/howmuch/registry/registry.go b/internal/howmuch/registry/registry.go
index 98ed3fe..76a538a 100644
--- a/internal/howmuch/registry/registry.go
+++ b/internal/howmuch/registry/registry.go
@@ -23,9 +23,10 @@
 package registry
 
 import (
+	"database/sql"
+
 	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/adapter/controller"
 	"git.vinchent.xyz/vinchent/howmuch/internal/pkg/core"
-	"github.com/jackc/pgx/v5"
 )
 
 // registry is an implementation of Registry interface.
@@ -33,7 +34,7 @@ import (
 // It might holds other drivers when the projects grows. For example
 // the object needed to connect to Redis or Kafka.
 type registry struct {
-	db    *pgx.Conn
+	db    *sql.DB
 	cache core.Cache
 }
 
@@ -45,7 +46,7 @@ type Registry interface {
 }
 
 // NewRegistry returns a new Registry's implementation.
-func NewRegistry(db *pgx.Conn, cache core.Cache) Registry {
+func NewRegistry(db *sql.DB, cache core.Cache) Registry {
 	return &registry{db: db, cache: cache}
 }
 
diff --git a/sqlc.yml b/sqlc.yml
index a512ce5..7c7a57c 100644
--- a/sqlc.yml
+++ b/sqlc.yml
@@ -28,4 +28,3 @@ sql:
     gen:
       go:
         out: "internal/howmuch/adapter/repo/sqlc"
-        sql_package: "pgx/v5"