diff --git a/backend/backend/idfm_interface/idfm_interface.py b/backend/backend/idfm_interface/idfm_interface.py
index 20ef89d..99ea17e 100644
--- a/backend/backend/idfm_interface/idfm_interface.py
+++ b/backend/backend/idfm_interface/idfm_interface.py
@@ -1,4 +1,5 @@
 from collections import defaultdict
+from logging import getLogger
 from re import compile as re_compile
 from time import time
 from typing import (
@@ -37,6 +38,10 @@ from .idfm_types import (
 from .ratp_types import Picto as RatpPicto
 
 
+
+logger = getLogger(__name__)
+
+
 class IdfmInterface:
 
     IDFM_ROOT_URL = "https://prim.iledefrance-mobilites.fr/marketplace"
@@ -358,9 +363,22 @@ class IdfmInterface:
 
             picto_id = fields.picto.id_ if fields.picto is not None else None
 
+            line_id = fields.id_line
+            try:
+                formatted_line_id = int(line_id[1:] if line_id[0] == "C" else line_id)
+            except ValueError:
+                logger.warning("Unable to format %s line id.", line_id)
+                continue
+
+            try:
+                operator_id = int(fields.operatorref)  # type: ignore
+            except (ValueError, TypeError):
+                logger.warning("Unable to format %s operator id.", fields.operatorref)
+                operator_id = 0
+
             ret.append(
                 Line(
-                    id=fields.id_line,
+                    id=formatted_line_id,
                     short_name=fields.shortname_line,
                     name=fields.name_line,
                     status=IdfmLineState(fields.status.value),
@@ -373,7 +391,7 @@ class IdfmInterface:
                     ),
                     colour_web_hexa=fields.colourweb_hexa,
                     text_colour_hexa=fields.textcolourprint_hexa,
-                    operator_id=optional_value(fields.operatorref),
+                    operator_id=operator_id,
                     operator_name=optional_value(fields.operatorname),
                     accessibility=IdfmState(fields.accessibility.value),
                     visual_signs_available=IdfmState(
@@ -403,13 +421,21 @@ class IdfmInterface:
                 fields.arrxepsg2154, fields.arryepsg2154
             )
 
+            try:
+                postal_region = int(fields.arrpostalregion)
+            except ValueError:
+                logger.warning(
+                    "Unable to format %s postal region.", fields.arrpostalregion
+                )
+                continue
+
             yield Stop(
                 id=int(fields.arrid),
                 name=fields.arrname,
                 epsg3857_x=epsg3857_point[0],
                 epsg3857_y=epsg3857_point[1],
                 town_name=fields.arrtown,
-                postal_region=fields.arrpostalregion,
+                postal_region=postal_region,
                 transport_mode=TransportMode(fields.arrtype.value),
                 version=fields.arrversion,
                 created_ts=created_ts,
diff --git a/backend/backend/models/line.py b/backend/backend/models/line.py
index 4888e48..786c585 100644
--- a/backend/backend/models/line.py
+++ b/backend/backend/models/line.py
@@ -27,7 +27,7 @@ from .stop import _Stop
 class LineStopAssociations(Base):
 
     id = mapped_column(BigInteger, primary_key=True)
-    line_id = mapped_column(String, ForeignKey("lines.id"))
+    line_id = mapped_column(BigInteger, ForeignKey("lines.id"))
     stop_id = mapped_column(BigInteger, ForeignKey("_stops.id"))
 
     __tablename__ = "line_stop_associations"
@@ -53,7 +53,7 @@ class Line(Base):
 
     db = db
 
-    id = mapped_column(String, primary_key=True)
+    id = mapped_column(BigInteger, primary_key=True)
 
     short_name = mapped_column(String)
     name = mapped_column(String, nullable=False)
@@ -68,7 +68,7 @@ class Line(Base):
     colour_web_hexa = mapped_column(String, nullable=False)
     text_colour_hexa = mapped_column(String, nullable=False)
 
-    operator_id = mapped_column(String)
+    operator_id = mapped_column(Integer)
     operator_name = mapped_column(String)
 
     accessibility = mapped_column(Enum(IdfmState), nullable=False)
diff --git a/backend/backend/models/stop.py b/backend/backend/models/stop.py
index 658869f..05e05e2 100644
--- a/backend/backend/models/stop.py
+++ b/backend/backend/models/stop.py
@@ -53,7 +53,7 @@ class _Stop(Base):
 
     name = mapped_column(String, nullable=False, index=True)
     town_name = mapped_column(String, nullable=False)
-    postal_region = mapped_column(String, nullable=False)
+    postal_region = mapped_column(Integer, nullable=False)
     epsg3857_x = mapped_column(Float, nullable=False)
     epsg3857_y = mapped_column(Float, nullable=False)
 
diff --git a/backend/backend/schemas/line.py b/backend/backend/schemas/line.py
index 8a65841..01feeed 100644
--- a/backend/backend/schemas/line.py
+++ b/backend/backend/schemas/line.py
@@ -46,7 +46,7 @@ class TransportMode(StrEnum):
 
 
 class Line(BaseModel):
-    id: str
+    id: int
     shortName: str
     name: str
     status: IdfmLineState
diff --git a/backend/main.py b/backend/main.py
index ff1acd5..e5a1f08 100755
--- a/backend/main.py
+++ b/backend/main.py
@@ -73,13 +73,11 @@ trace.set_tracer_provider(TracerProvider())
 trace.get_tracer_provider().add_span_processor(BatchSpanProcessor(OTLPSpanExporter()))
 tracer = trace.get_tracer(APP_NAME)
 
-with tracer.start_as_current_span("foo"):
-    print("Hello world!")
-
 
 idfm_interface = IdfmInterface(API_KEY, db)
 
 
+# TODO: Add command line argument to force database reset.
 @app.on_event("startup")
 async def startup():
     await db.connect(DB_PATH, clear_static_data=True)
@@ -102,7 +100,7 @@ def optional_datetime_to_ts(dt: datetime | None) -> int | None:
 
 
 @app.get("/line/{line_id}", response_model=LineSchema)
-async def get_line(line_id: str) -> LineSchema:
+async def get_line(line_id: int) -> LineSchema:
     line: Line | None = await Line.get_by_id(line_id)
 
     if line is None: