diff --git a/modules/server/src/main/scala/io/kevchuang/reviewboard/Application.scala b/modules/server/src/main/scala/io/kevchuang/reviewboard/Application.scala
index 6fcfcc3..b2de283 100644
--- a/modules/server/src/main/scala/io/kevchuang/reviewboard/Application.scala
+++ b/modules/server/src/main/scala/io/kevchuang/reviewboard/Application.scala
@@ -3,20 +3,30 @@ package io.kevchuang.reviewboard
 import io.kevchuang.reviewboard.http.routes.*
 import io.kevchuang.reviewboard.http.server.{HttpServer, HttpServerLive}
 import io.kevchuang.reviewboard.services.Services
+import io.kevchuang.reviewboard.services.company.CompanyServiceLive
+import io.kevchuang.reviewboard.services.db.{DatabaseService, InMemoryDatabase}
 import io.kevchuang.reviewboard.services.health.*
 import zio.*
 import zio.http.Server
 
 object Application extends ZIOAppDefault:
-  private val program: ZIO[HttpServer & Server & Services, Throwable, Unit] =
+  private val program
+      : ZIO[HttpServer & Server & DatabaseService & Services, Throwable, Unit] =
     for
-      healthRoutes <- HealthRoutes.make
-      routes        = healthRoutes.routes
-      _            <- HttpServer.start(routes)
+      companiesRoutes <- CompaniesRoutes.make
+      healthRoutes    <- HealthRoutes.make
+      routes           = companiesRoutes.routes ++ healthRoutes.routes
+      _               <- HttpServer.start(routes)
     yield ()
 
   override def run: ZIO[Any with ZIOAppArgs with Scope, Any, Any] =
     program
-      .provide(Server.default, HttpServerLive.live, HealthServiceLive.live)
+      .provide(
+        Server.default,
+        HttpServerLive.live,
+        CompanyServiceLive.live,
+        InMemoryDatabase.live,
+        HealthServiceLive.live
+      )
 
 end Application
diff --git a/modules/server/src/main/scala/io/kevchuang/reviewboard/domain/company.scala b/modules/server/src/main/scala/io/kevchuang/reviewboard/domain/company.scala
new file mode 100644
index 0000000..439f629
--- /dev/null
+++ b/modules/server/src/main/scala/io/kevchuang/reviewboard/domain/company.scala
@@ -0,0 +1,82 @@
+package io.kevchuang.reviewboard.domain
+
+import io.github.iltotore.iron.constraint.all.*
+import io.github.iltotore.iron.zioJson.given
+import zio.json.*
+import io.github.iltotore.iron.*
+import io.kevchuang.reviewboard.domain.error.DomainError
+import io.kevchuang.reviewboard.types.{NotEmpty, OnlyLetters}
+import sttp.tapir.Schema
+import sttp.tapir.generic.auto.*
+
+object company:
+  opaque type CompanyId = Long :| Positive
+  object CompanyId extends RefinedTypeOps[Long, Positive, CompanyId]
+
+  opaque type CompanyName <: String :| Alphanumeric = String :| Alphanumeric
+  object CompanyName extends RefinedTypeOps[String, Alphanumeric, CompanyName]
+
+  opaque type CompanySlug = String :| NotEmpty
+  object CompanySlug extends RefinedTypeOps[String, NotEmpty, CompanySlug]
+
+  opaque type CountryName = String :| OnlyLetters
+  object CountryName extends RefinedTypeOps[String, OnlyLetters, CountryName]
+
+  opaque type IndustryName = String :| OnlyLetters
+  object IndustryName extends RefinedTypeOps[String, OnlyLetters, IndustryName]
+
+  opaque type LocationName = String :| OnlyLetters
+  object LocationName extends RefinedTypeOps[String, OnlyLetters, LocationName]
+
+  private type TagNameConstraint = NotEmpty & LettersLowerCase
+  opaque type TagName            = String :| TagNameConstraint
+  object TagName extends RefinedTypeOps[String, TagNameConstraint, TagName]
+
+  opaque type Url = String :| ValidURL
+  object Url extends RefinedTypeOps[String, ValidURL, Url]
+
+  final case class Company(
+      id: CompanyId,
+      slug: CompanySlug,
+      name: CompanyName,
+      url: Url,
+      location: Option[LocationName] = None,
+      country: Option[CountryName] = None,
+      industry: Option[IndustryName] = None,
+      image: Option[Url] = None,
+      tags: List[TagName] = List.empty[TagName]
+  )
+  object Company:
+    given JsonCodec[Company]     = DeriveJsonCodec.gen[Company]
+    inline given Schema[Company] = Schema.derived[Company]
+  end Company
+
+  final case class CreateCompany(
+      name: CompanyName,
+      url: Url,
+      location: Option[LocationName] = None,
+      country: Option[CountryName] = None,
+      industry: Option[IndustryName] = None,
+      image: Option[Url] = None,
+      tags: List[TagName] = List.empty[TagName]
+  )
+  object CreateCompany:
+    given JsonCodec[CreateCompany]     = DeriveJsonCodec.gen[CreateCompany]
+    inline given Schema[CreateCompany] = Schema.derived[CreateCompany]
+  end CreateCompany
+
+  sealed trait CompanyDomainError extends DomainError
+  final case class CompanyAlreadyExists(companyName: CompanyName)
+      extends CompanyDomainError
+  object CompanyAlreadyExists:
+    given JsonCodec[CompanyAlreadyExists] =
+      DeriveJsonCodec.gen[CompanyAlreadyExists]
+  end CompanyAlreadyExists
+
+  final case class UnableToGenerateCompanyId(message: String)
+      extends CompanyDomainError
+  object UnableToGenerateCompanyId:
+    given JsonCodec[UnableToGenerateCompanyId] =
+      DeriveJsonCodec.gen[UnableToGenerateCompanyId]
+  end UnableToGenerateCompanyId
+end company
diff --git a/modules/server/src/main/scala/io/kevchuang/reviewboard/domain/error.scala b/modules/server/src/main/scala/io/kevchuang/reviewboard/domain/error.scala
new file mode 100644
index 0000000..ee418a9
--- /dev/null
+++ b/modules/server/src/main/scala/io/kevchuang/reviewboard/domain/error.scala
@@ -0,0 +1,5 @@
+package io.kevchuang.reviewboard.domain
+
+object error:
+  trait DomainError extends Throwable
+end error
diff --git a/modules/server/src/main/scala/io/kevchuang/reviewboard/http/endpoints/CreateCompanyEndpoint.scala b/modules/server/src/main/scala/io/kevchuang/reviewboard/http/endpoints/CreateCompanyEndpoint.scala
new file mode 100644
index 0000000..84d10b5
--- /dev/null
+++ b/modules/server/src/main/scala/io/kevchuang/reviewboard/http/endpoints/CreateCompanyEndpoint.scala
@@ -0,0 +1,54 @@
+package io.kevchuang.reviewboard.http.endpoints
+
+import io.kevchuang.reviewboard.domain.company.{*, given}
+import io.kevchuang.reviewboard.services.company.CompanyService
+import io.kevchuang.reviewboard.services.db.DatabaseService
+import sttp.model.StatusCode
+import sttp.tapir.*
+import sttp.tapir.codec.iron.{*, given}
+import sttp.tapir.generic.auto.*
+import sttp.tapir.json.zio.*
+import zio.*
+
+final case class CreateCompanyEndpoint()
+    extends HttpEndpoint[
+      DatabaseService & CompanyService,
+      CreateCompany,
+      CompanyDomainError,
+      Company
+    ]:
+  def endpointDescription
+      : ApiEndpoint[CreateCompany, CompanyDomainError, Company] =
+    endpoint
+      .tag("companies")
+      .name("create")
+      .description("create a listing for a company")
+      .in("companies")
+      .post
+      .in(jsonBody[CreateCompany])
+      .errorOut(
+        oneOf[CompanyDomainError](
+          oneOfVariant[CompanyAlreadyExists](
+            StatusCode.BadRequest,
+            jsonBody[CompanyAlreadyExists]
+          ),
+          oneOfVariant[UnableToGenerateCompanyId](
+            StatusCode.BadRequest,
+            jsonBody[UnableToGenerateCompanyId]
+          )
+        )
+      )
+      .out(jsonBody[Company])
+
+  def endpointLogic: CreateCompany => ZIO[
+    DatabaseService & CompanyService,
+    CompanyDomainError,
+    Company
+  ] =
+    CompanyService.createCompany
+end CreateCompanyEndpoint
+
+object CreateCompanyEndpoint:
+  def make: UIO[CreateCompanyEndpoint] =
+    ZIO.succeed(CreateCompanyEndpoint())
+end CreateCompanyEndpoint
diff --git a/modules/server/src/main/scala/io/kevchuang/reviewboard/http/endpoints/HealthEndpoint.scala b/modules/server/src/main/scala/io/kevchuang/reviewboard/http/endpoints/HealthEndpoint.scala
index a4f1f61..5e6890b 100644
--- a/modules/server/src/main/scala/io/kevchuang/reviewboard/http/endpoints/HealthEndpoint.scala
+++ b/modules/server/src/main/scala/io/kevchuang/reviewboard/http/endpoints/HealthEndpoint.scala
@@ -9,7 +9,7 @@ import sttp.tapir.generic.auto.*
 import sttp.tapir.json.zio.{*, given}
 import zio.*
 
-final case class HealthEndpoint(health: HealthService)
+final case class HealthEndpoint()
     extends HttpEndpoint[HealthService, Unit, Unit, HealthCheckResponse]:
   def endpointDescription: ApiEndpoint[Unit, Unit, HealthCheckResponse] =
     endpoint
@@ -20,12 +20,11 @@ final case class HealthEndpoint(health: HealthService)
       .in("health")
       .out(jsonBody[HealthCheckResponse])
 
-  def endpointLogic: Unit => UIO[HealthCheckResponse] = _ => health.checkHealth
+  def endpointLogic: Unit => URIO[HealthService, HealthCheckResponse] = _ =>
+    HealthService.checkHealth
 end HealthEndpoint
 
 object HealthEndpoint:
-  def make: RIO[HealthService, HealthEndpoint] =
-    for health <- ZIO.service[HealthService]
-    yield HealthEndpoint(health)
-
+  def make: UIO[HealthEndpoint] =
+    ZIO.succeed(HealthEndpoint())
 end HealthEndpoint
diff --git a/modules/server/src/main/scala/io/kevchuang/reviewboard/http/routes/CompaniesRoutes.scala b/modules/server/src/main/scala/io/kevchuang/reviewboard/http/routes/CompaniesRoutes.scala
new file mode 100644
index 0000000..db0c579
--- /dev/null
+++ b/modules/server/src/main/scala/io/kevchuang/reviewboard/http/routes/CompaniesRoutes.scala
@@ -0,0 +1,22 @@
+package io.kevchuang.reviewboard.http.routes
+
+import io.kevchuang.reviewboard.http.endpoints.CreateCompanyEndpoint
+import io.kevchuang.reviewboard.services.company.CompanyService
+import io.kevchuang.reviewboard.services.db.DatabaseService
+import sttp.tapir.ztapir.ZServerEndpoint
+import zio.*
+
+private case class CompaniesRoutes(
+    createCompanyEndpoint: CreateCompanyEndpoint
+) extends HttpRoute[DatabaseService & CompanyService]:
+  def endpoints: List[ZServerEndpoint[DatabaseService & CompanyService, Any]] =
+    List(
+      createCompanyEndpoint.serverEndpoint
+    )
+end CompaniesRoutes
+
+object CompaniesRoutes:
+  def make: UIO[CompaniesRoutes] =
+    for createCompany <- CreateCompanyEndpoint.make
+    yield CompaniesRoutes(createCompany)
+end CompaniesRoutes
diff --git a/modules/server/src/main/scala/io/kevchuang/reviewboard/http/routes/HealthRoutes.scala b/modules/server/src/main/scala/io/kevchuang/reviewboard/http/routes/HealthRoutes.scala
index 989c8f5..fce2344 100644
--- a/modules/server/src/main/scala/io/kevchuang/reviewboard/http/routes/HealthRoutes.scala
+++ b/modules/server/src/main/scala/io/kevchuang/reviewboard/http/routes/HealthRoutes.scala
@@ -2,7 +2,6 @@ package io.kevchuang.reviewboard.http.routes
 
 import io.kevchuang.reviewboard.http.endpoints.HealthEndpoint
 import io.kevchuang.reviewboard.services.health.HealthService
-import sttp.tapir.server.ServerEndpoint
 import sttp.tapir.ztapir.*
 import zio.*
 
diff --git a/modules/server/src/main/scala/io/kevchuang/reviewboard/services/company/CompanyService.scala b/modules/server/src/main/scala/io/kevchuang/reviewboard/services/company/CompanyService.scala
new file mode 100644
index 0000000..e219b51
--- /dev/null
+++ b/modules/server/src/main/scala/io/kevchuang/reviewboard/services/company/CompanyService.scala
@@ -0,0 +1,18 @@
+package io.kevchuang.reviewboard.services.company
+
+import io.kevchuang.reviewboard.domain.company.*
+import io.kevchuang.reviewboard.services.db.DatabaseService
+import zio.*
+
+trait CompanyService:
+  def createCompany(
+      company: CreateCompany
+  ): ZIO[DatabaseService, CompanyDomainError, Company]
+end CompanyService
+
+object CompanyService:
+  def createCompany(
+      company: CreateCompany
+  ): ZIO[DatabaseService & CompanyService, CompanyDomainError, Company] =
+    ZIO.serviceWithZIO[CompanyService](_.createCompany(company))
+end CompanyService
diff --git a/modules/server/src/main/scala/io/kevchuang/reviewboard/services/company/CompanyServiceLive.scala b/modules/server/src/main/scala/io/kevchuang/reviewboard/services/company/CompanyServiceLive.scala
new file mode 100644
index 0000000..c00386a
--- /dev/null
+++ b/modules/server/src/main/scala/io/kevchuang/reviewboard/services/company/CompanyServiceLive.scala
@@ -0,0 +1,65 @@
+package io.kevchuang.reviewboard.services.company
+
+import io.kevchuang.reviewboard.domain.company.*
+import io.kevchuang.reviewboard.services.db.DatabaseService
+import zio.*
+import io.github.iltotore.iron.*
+import io.github.iltotore.iron.constraint.all.*
+import io.kevchuang.reviewboard.types.NotEmpty
+
+object CompanyServiceLive:
+  lazy val live: ULayer[CompanyService] = ZLayer.succeed(
+    new CompanyService:
+      private def generateCompanyId
+          : ZIO[DatabaseService, UnableToGenerateCompanyId, CompanyId] =
+        DatabaseService.countCompanies
+          .flatMap: id =>
+            ZIO
+              .fromEither(id.refineEither[Positive])
+              .mapBoth(
+                error => UnableToGenerateCompanyId(error),
+                companyId => CompanyId(companyId)
+              )
+
+      private def generateCompanySlug(
+          companyName: CompanyName
+      ): UIO[CompanySlug] =
+        ZIO.succeed(
+          CompanySlug(
+            companyName
+              .replaceAll(" +", " ")
+              .split(" ")
+              .map(_.toLowerCase)
+              .mkString("-")
+              .assume[NotEmpty]
+          )
+        )
+
+      private def generateCompany(
+          company: CreateCompany
+      ): ZIO[DatabaseService, UnableToGenerateCompanyId, Company] =
+        for
+          companyId   <- generateCompanyId
+          companySlug <- generateCompanySlug(company.name)
+        yield Company(
+          id = companyId,
+          slug = companySlug,
+          name = company.name,
+          url = company.url,
+          location = company.location,
+          country = company.country,
+          industry = company.industry,
+          image = company.image,
+          tags = company.tags
+        )
+
+      override def createCompany(
+          company: CreateCompany
+      ): ZIO[DatabaseService, CompanyDomainError, Company] =
+        DatabaseService
+          .existsCompany(company.name)
+          .flatMap: exists =>
+            if exists then ZIO.fail(CompanyAlreadyExists(company.name))
+            else generateCompany(company).tap(DatabaseService.insertCompany)
+  )
+end CompanyServiceLive
diff --git a/modules/server/src/main/scala/io/kevchuang/reviewboard/services/db/DatabaseService.scala b/modules/server/src/main/scala/io/kevchuang/reviewboard/services/db/DatabaseService.scala
new file mode 100644
index 0000000..a15dbe8
--- /dev/null
+++ b/modules/server/src/main/scala/io/kevchuang/reviewboard/services/db/DatabaseService.scala
@@ -0,0 +1,25 @@
+package io.kevchuang.reviewboard.services.db
+
+import io.kevchuang.reviewboard.domain.company.*
+import zio.*
+
+trait DatabaseService:
+  def countCompanies: UIO[Long]
+  def existsCompany(companyName: CompanyName): UIO[Boolean]
+  def insertCompany(company: Company): UIO[Unit]
+end DatabaseService
+
+object DatabaseService:
+  def countCompanies: URIO[DatabaseService, Long] =
+    ZIO.serviceWithZIO[DatabaseService](_.countCompanies)
+
+  def existsCompany(
+      companyName: CompanyName
+  ): URIO[DatabaseService, Boolean] =
+    ZIO.serviceWithZIO[DatabaseService](_.existsCompany(companyName))
+
+  def insertCompany(
+      company: Company
+  ): URIO[DatabaseService, Unit] =
+    ZIO.serviceWithZIO[DatabaseService](_.insertCompany(company))
+end DatabaseService
diff --git a/modules/server/src/main/scala/io/kevchuang/reviewboard/services/db/InMemoryDatabase.scala b/modules/server/src/main/scala/io/kevchuang/reviewboard/services/db/InMemoryDatabase.scala
new file mode 100644
index 0000000..10c877f
--- /dev/null
+++ b/modules/server/src/main/scala/io/kevchuang/reviewboard/services/db/InMemoryDatabase.scala
@@ -0,0 +1,26 @@
+package io.kevchuang.reviewboard.services.db
+
+import io.kevchuang.reviewboard.domain.company.*
+import zio.*
+
+import scala.collection.mutable
+
+final case class InMemoryDatabase(database: mutable.Map[CompanyId, Company])
+    extends DatabaseService:
+  override def countCompanies: UIO[Long] =
+    ZIO.succeed(database.size.toLong)
+
+  override def existsCompany(companyName: CompanyName): UIO[Boolean] =
+    ZIO.succeed(database.exists((_, c) => c.name == companyName))
+
+  override def insertCompany(
+      company: Company
+  ): UIO[Unit] =
+    ZIO.succeed(database.addOne(company.id -> company))
+end InMemoryDatabase
+
+object InMemoryDatabase:
+  val live: ULayer[InMemoryDatabase] =
+    ZLayer.succeed:
+      InMemoryDatabase(mutable.Map.empty[CompanyId, Company])
+end InMemoryDatabase
diff --git a/modules/server/src/main/scala/io/kevchuang/reviewboard/services/package.scala b/modules/server/src/main/scala/io/kevchuang/reviewboard/services/package.scala
index ac17fb1..735c5b7 100644
--- a/modules/server/src/main/scala/io/kevchuang/reviewboard/services/package.scala
+++ b/modules/server/src/main/scala/io/kevchuang/reviewboard/services/package.scala
@@ -1,7 +1,8 @@
 package io.kevchuang.reviewboard
 
+import io.kevchuang.reviewboard.services.company.CompanyService
 import io.kevchuang.reviewboard.services.health.HealthService
 
 package object services:
-  type Services = HealthService
+  type Services = CompanyService & HealthService
 end services
diff --git a/modules/server/src/main/scala/io/kevchuang/reviewboard/types/package.scala b/modules/server/src/main/scala/io/kevchuang/reviewboard/types/package.scala
index b2308d6..c8e592a 100644
--- a/modules/server/src/main/scala/io/kevchuang/reviewboard/types/package.scala
+++ b/modules/server/src/main/scala/io/kevchuang/reviewboard/types/package.scala
@@ -1,7 +1,15 @@
 package io.kevchuang.reviewboard
 
 import io.github.iltotore.iron.constraint.all.*
+import zio.http.URL
+import zio.json.*
 
 package object types:
-  type NotEmpty = Not[Empty]
+  type OnlyLetters = ForAll[Letter] DescribedAs "Should contain only letters"
+  type NotEmpty    = Not[Empty] DescribedAs "Should not be empty"
+
+  given JsonDecoder[URL] = JsonDecoder[String].mapOrFail(url =>
+    URL.decode(url).fold(e => Left(e.getMessage), value => Right(value))
+  )
+  given JsonEncoder[URL] = JsonEncoder[String].contramap(_.encode)
 end types
diff --git a/project/ScalaSettings.scala b/project/ScalaSettings.scala
index c9ba1cf..09e0fe5 100644
--- a/project/ScalaSettings.scala
+++ b/project/ScalaSettings.scala
@@ -18,6 +18,8 @@ object ScalaSettings {
     "-language:higherKinds",
     "-language:implicitConversions",
     "-unchecked",
-    "-deprecation"
+    "-deprecation",
+    "-Xmax-inlines",
+    "64"
   )
 }