diff --git a/kingfisher_scrapy/base_spider.py b/kingfisher_scrapy/base_spider.py
index 4036afb23..c0eda20df 100644
--- a/kingfisher_scrapy/base_spider.py
+++ b/kingfisher_scrapy/base_spider.py
@@ -5,8 +5,10 @@
 from io import BytesIO
 from zipfile import ZipFile
 
+import ijson
 import scrapy
 
+from kingfisher_scrapy import util
 from kingfisher_scrapy.exceptions import SpiderArgumentError
 
 
@@ -36,6 +38,10 @@ class BaseSpider(scrapy.Spider):
 
         scrapy crawl spider_name -a note='Started by NAME.'
     """
+
+    MAX_SAMPLE = 10
+    MAX_RELEASES_PER_PACKAGE = 100
+
     def __init__(self, sample=None, note=None, from_date=None, until_date=None, *args, **kwargs):
         super().__init__(*args, **kwargs)
 
@@ -152,18 +158,46 @@ def _get_crawl_path(self):
             name += '_sample'
         return os.path.join(name, self.get_start_time('%Y%m%d_%H%M%S'))
 
+    def _build_file_item(self, number, line, data_type, url, encoding):
+        return {
+            'success': True,
+            'number': number,
+            'file_name': 'data.json',
+            'data': line,
+            'data_type': data_type,
+            'url': url,
+            'encoding': encoding,
+        }
+
     def parse_json_lines(self, f, data_type, url, encoding='utf-8'):
         for number, line in enumerate(f, 1):
-            yield {
-                'success': True,
-                'number': number,
-                'file_name': 'data.json',
-                'data': line,
-                'data_type': data_type,
-                'url': url,
-                'encoding': encoding,
-            }
-            if self.sample and number > 9:
+            if self.sample and number > self.MAX_SAMPLE:
+                break
+            if isinstance(line, bytes):
+                line = line.decode()
+            yield self._build_file_item(number, line, data_type, url, encoding)
+
+    def get_package(self, f, array_name):
+        """
+        Returns the package data from a array_name_package object
+        """
+        package = {}
+        for item in util.items(ijson.parse(f), '', array_name=array_name):
+            package.update(item)
+        return package
+
+    def parse_json_array(self, f_package, f_list, data_type, url, encoding='utf-8', array_field_name='releases'):
+        if self.sample:
+            size = self.MAX_SAMPLE
+        else:
+            size = self.MAX_RELEASES_PER_PACKAGE
+
+        package = self.get_package(f_package, array_field_name)
+
+        for number, items in enumerate(util.grouper(ijson.items(f_list, '{}.item'.format(array_field_name)), size), 1):
+            package[array_field_name] = [item for item in items if item is not None]
+            yield self._build_file_item(number, json.dumps(package, default=util.default), data_type, url, encoding)
+            if self.sample:
                 break
 
 
@@ -172,15 +206,18 @@ def parse_zipfile(self, response, data_type, file_format=None, encoding='utf-8')
         """
         Handling response with JSON data in ZIP files
 
-        :param str file_format: The zipped files format. If this is set to 'json_lines', then the zipped file will be
-                                slitted by lines before send it to kingfisher-process and only the zip file will be
-                                stored as file.
+        :param str file_format: The zipped file's format. If this is set to "json_lines", then each line of the zipped
+                                file will be yielded separately. If this is set to "release_package", then the releases
+                                will be re-packaged in groups of :const:~kingfisher_scrapy.base_spider.BaseSpider.
+                                `~kingfisher_scrapy.base_spider.BaseSpider.MAX_RELEASES_PER_PACKAGE` and yielded.
+                                In both cases, only the zipped file will be saved to disk. If this is not set, the file
+                                will be yielded and saved to disk.
         :param response response: the response that contains the zip file.
         :param str data_type: the zipped files data_type
         :param str encoding: the zipped files encoding. Default to utf-8
         """
         if response.status == 200:
-            if file_format == 'json_lines':
+            if file_format:
                 self.save_response_to_disk(response, 'file.zip')
             zip_file = ZipFile(BytesIO(response.body))
             for finfo in zip_file.infolist():
@@ -190,6 +227,10 @@ def parse_zipfile(self, response, data_type, file_format=None, encoding='utf-8')
                 data = zip_file.open(finfo.filename)
                 if file_format == 'json_lines':
                     yield from self.parse_json_lines(data, data_type, response.request.url, encoding=encoding)
+                elif file_format == 'release_package':
+                    package = zip_file.open(finfo.filename)
+                    yield from self.parse_json_array(package, data, data_type, response.request.url,
+                                                     encoding=encoding)
                 else:
                     yield self.save_data_to_disk(data.read(), filename, data_type=data_type, url=response.request.url,
                                                  encoding=encoding)
diff --git a/kingfisher_scrapy/spiders/argentina_buenos_aires.py b/kingfisher_scrapy/spiders/argentina_buenos_aires.py
index 6a4ae297d..fb9ccff2c 100644
--- a/kingfisher_scrapy/spiders/argentina_buenos_aires.py
+++ b/kingfisher_scrapy/spiders/argentina_buenos_aires.py
@@ -1,14 +1,20 @@
-import hashlib
 import json
-from io import BytesIO
-from zipfile import ZipFile
 
 import scrapy
 
-from kingfisher_scrapy.base_spider import BaseSpider
+from kingfisher_scrapy.base_spider import ZipSpider
 
 
-class ArgentinaBuenosAires(BaseSpider):
+class ArgentinaBuenosAires(ZipSpider):
+    """
+    Bulk download documentation
+      https://data.buenosaires.gob.ar/dataset/buenos-aires-compras/archivo/2a3d077c-71b6-4ba7-8924-f3e38cf1b8fc
+    API documentation
+      https://data.buenosaires.gob.ar/acerca/ckan
+    Spider arguments
+      sample
+        Downloads the zip file and sends 10 releases to kingfisher process.
+    """
     name = 'argentina_buenos_aires'
     start_urls = ['https://data.buenosaires.gob.ar/api/3/action/package_show?id=buenos-aires-compras']
     # the data list service takes too long to be downloaded, so we increase the download timeout
@@ -17,29 +23,22 @@ class ArgentinaBuenosAires(BaseSpider):
     def start_requests(self):
         yield scrapy.Request(
             url='https://data.buenosaires.gob.ar/api/3/action/package_show?id=buenos-aires-compras',
-            meta={'type': 'meta'}
+            callback=self.parse_list
         )
 
-    def parse(self, response):
+    def parse_list(self, response):
         if response.status == 200:
-            if response.request.meta['type'] == 'meta':
-                data = json.loads(response.text)
-                for resource in data['result']['resources']:
-                    if resource['format'].upper() == 'JSON':
-                        yield scrapy.Request(
-                            url=resource['url'],
-                            meta={'type': 'data'}
-                        )
-            else:
-                zip_file = ZipFile(BytesIO(response.body))
-                for finfo in zip_file.infolist():
-                    data = zip_file.open(finfo.filename).read()
-                    yield self.save_data_to_disk(data, finfo.filename, url=response.request.url,
-                                                 data_type='release_package')
+            data = json.loads(response.text)
+            for resource in data['result']['resources']:
+                if resource['format'].upper() == 'JSON':
+                    yield scrapy.Request(url=resource['url'])
         else:
             yield {
                 'success': False,
-                'file_name': hashlib.md5(response.request.url.encode('utf-8')).hexdigest() + '.json',
+                'file_name': 'list.json',
                 'url': response.request.url,
                 'errors': {'http_code': response.status}
             }
+
+    def parse(self, response):
+        yield from self.parse_zipfile(response, 'release_package', file_format='release_package')
diff --git a/kingfisher_scrapy/spiders/portugal.py b/kingfisher_scrapy/spiders/portugal.py
index 7b998d0c4..67c054db6 100644
--- a/kingfisher_scrapy/spiders/portugal.py
+++ b/kingfisher_scrapy/spiders/portugal.py
@@ -43,5 +43,5 @@ def parse_list(self, response):
             }
 
     def parse(self, response):
-        yield from self.parse_zipfile(response, data_type='record_package_json_lines',
+        yield from self.parse_zipfile(response, data_type='record_package',
                                       file_format='json_lines', encoding='iso-8859-1')
diff --git a/kingfisher_scrapy/util.py b/kingfisher_scrapy/util.py
new file mode 100644
index 000000000..7317da914
--- /dev/null
+++ b/kingfisher_scrapy/util.py
@@ -0,0 +1,60 @@
+import itertools
+import json
+from decimal import Decimal
+
+from ijson import ObjectBuilder, utils
+
+
+@utils.coroutine
+def items_basecoro(target, prefix, map_type=None, array_name=None):
+    """
+    This is copied from ``ijson/common.py``. An ``array_name`` argument is added. If the ``array_name`` is in the
+    current path, the current event is skipped. Otherwise, the method is identical.
+    """
+    while True:
+        current, event, value = (yield)
+        if array_name and array_name in current:
+            continue
+        if current == prefix:
+            if event in ('start_map', 'start_array'):
+                builder = ObjectBuilder(map_type=map_type)
+                end_event = event.replace('start', 'end')
+                while (current, event) != (prefix, end_event):
+                    builder.event(event, value)
+                    current, event, value = (yield)
+                del builder.containers[:]
+                target.send(builder.value)
+            else:
+                target.send(value)
+
+
+def items(events, prefix, map_type=None, array_name=None):
+    """
+    This is copied from ``ijson/common.py``. An ``array_name`` argument is added, which is passed as a keyword argument
+    to :meth:`~kingfisher_scrapy.util.items_basecoro`. Otherwise, the method is identical.
+
+    """
+    return utils.coros2gen(events,
+                           (items_basecoro, (prefix,), {'map_type': map_type, 'array_name': array_name})
+                           )
+
+
+def default(obj):
+    """
+    Dumps JSON to a string, and returns it.
+    """
+    if isinstance(obj, Decimal):
+        return float(obj)
+    try:
+        iterable = iter(obj)
+    except TypeError:
+        pass
+    else:
+        return list(iterable)
+    return json.JSONEncoder().default(obj)
+
+
+# See `grouper` recipe: https://docs.python.org/3.8/library/itertools.html#recipes
+def grouper(iterable, n, fillvalue=None):
+    args = [iter(iterable)] * n
+    return itertools.zip_longest(*args, fillvalue=fillvalue)
diff --git a/requirements.in b/requirements.in
index ab64af98c..34c50ac3d 100644
--- a/requirements.in
+++ b/requirements.in
@@ -5,3 +5,4 @@ rarfile
 requests
 Scrapy
 scrapyd-client
+ijson>=3
\ No newline at end of file
diff --git a/requirements.txt b/requirements.txt
index 6541b8237..669121e80 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -14,6 +14,7 @@ cryptography==2.8         # via pyopenssl, scrapy, service-identity
 cssselect==1.1.0          # via parsel, scrapy
 hyperlink==19.0.0         # via twisted
 idna==2.8                 # via hyperlink, requests
+ijson==3.0.3
 incremental==17.5.0       # via twisted
 lxml==4.4.2               # via parsel, scrapy
 parsel==1.5.2             # via scrapy
diff --git a/requirements_dev.txt b/requirements_dev.txt
index 3d2cb46d6..1ebbde865 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -20,6 +20,7 @@ entrypoints==0.3          # via flake8
 flake8==3.7.9
 hyperlink==19.0.0
 idna==2.8
+ijson==3.0.3
 importlib-metadata==1.3.0  # via pluggy, pytest
 incremental==17.5.0
 isort==4.3.21
diff --git a/tests/test_base_spider.py b/tests/test_base_spider.py
index 01ee92b26..dbfdab5d8 100644
--- a/tests/test_base_spider.py
+++ b/tests/test_base_spider.py
@@ -223,9 +223,8 @@ def test_parse_zipfile_json_lines():
         tmp = os.path.join(files_store, 'test/20010203_040506')
         os.makedirs(tmp)
         with open(tmp + "test.json", 'w') as f:
-            f.write('{"key": "value"}\n{"key": "value"}\n{"key": "value"}\n{"key": "value"}\n{"key": "value"}'
-                    '\n{"key": "value"}\n{"key": "value"}\n{"key": "value"}\n{"key": "value"}\n{"key": "value"}'
-                    '\n{"key": "value"}')
+            for i in range(10):
+                f.write('{"key": "value"}\n')
         with ZipFile(tmp + '/test.zip', 'w') as z:
             z.write(tmp + "test.json")
         with open(tmp + '/test.zip', 'rb') as z:
@@ -242,6 +241,44 @@ def test_parse_zipfile_json_lines():
         assert total == 10
 
 
+def test_parse_zipfile_release_package():
+    response = text.TextResponse('test')
+    response.status = 200
+    response.request = Mock()
+    response.request.meta = {'kf_filename': 'test.json'}
+    response.request.url = 'url'
+    with TemporaryDirectory() as tmpdirname:
+        files_store = os.path.join(tmpdirname, 'data')
+        tmp = os.path.join(files_store, 'test/20010203_040506')
+        os.makedirs(tmp)
+        with open(tmp + "test.json", 'w') as f:
+            release = {'releases': [], 'publisher': {'name': 'test'},
+                       'extensions': ['a', 'b'], 'license': 'test', 'extra': 1.1}
+            for i in range(110):
+                release['releases'].append({'key': 'value'})
+            json.dump(release, f)
+        with ZipFile(tmp + '/test.zip', 'w') as z:
+            z.write(tmp + "test.json")
+        with open(tmp + '/test.zip', 'rb') as z:
+            response = response.replace(body=z.read())
+        spider = spider_with_crawler(spider_class=ZipSpider)
+        spider.crawler.settings['FILES_STORE'] = files_store
+        actual = spider.parse_zipfile(response, None, file_format='release_package').__next__()
+        data = json.loads(actual['data'])
+        assert actual['success'] is True and actual['number'] == 1
+        assert data['publisher']['name'] == 'test'
+        assert data['extensions'] == ['a', 'b']
+        assert len(data['releases']) == spider.MAX_RELEASES_PER_PACKAGE
+        spider.sample = True
+        total = 0
+        for item in spider.parse_zipfile(response, None, file_format='release_package'):
+            total = total + 1
+            data = json.loads(item['data'])
+            assert item['success'] is True and item['number'] == total
+            assert len(data['releases']) == spider.MAX_SAMPLE
+        assert total == 1
+
+
 def test_date_arguments():
     test_date = '2000-01-01'
     error_message = "time data 'test' does not match format '%Y-%m-%d'"