| Name | Lines of code | Maintainability | Test coverage |
| lib/mongo/server/monitor.rb | 183 | B 4 hrs | |
| lib/mongo/protocol/message.rb | 190 | B 6 hrs | |
| lib/mongo/socket/ssl.rb | 205 | B 5 hrs | |
| lib/mongo/protocol/msg.rb | 206 | B 4 hrs | |
| lib/mongo/socket.rb | 225 | C 1 day | |
| lib/mongo/collection.rb | 225 | C 7 hrs | |
| lib/mongo/cursor.rb | 226 | C 7 hrs | |
| lib/mongo/socket/ocsp_verifier.rb | 241 | D 1 day | |
| lib/mongo/collection/view/writable.rb | 250 | D 3 days | |
| lib/mongo/retryable.rb | 254 | D 1 day | |
| lib/mongo/collection/view/readable.rb | 276 | D 2 days | |
| lib/mongo/server/description.rb | 290 | D 2 days | |
| lib/mongo/uri.rb | 295 | D 2 days | |
| lib/mongo/server.rb | 298 | C 1 day | |
| lib/mongo/server_selector/base.rb | 320 | D 3 days | |
| lib/mongo/uri/options_mapper.rb | 337 | D 1 day | |
| lib/mongo/cluster/sdam_flow.rb | 399 | D 2 days | |
| lib/mongo/crypt/binding.rb | 416 | C 1 day | |
| lib/mongo/server/connection_pool.rb | 468 | F 4 days | |
| lib/mongo/cluster.rb | 472 | F 4 days | |
| lib/mongo/session.rb | 509 | F 5 days | |
| lib/mongo/client.rb | 672 | F 1 wk | |
| lib/mongo/auth/stringprep/unicode_normalize/tables.rb | 1,161 | D 2 days | |
| lib/mongo/auth/stringprep/tables.rb | 3,148 | F 1 wk |