diff --git a/api/.ruby-version b/api/.ruby-version
index 9c25013db..2aa513199 100644
--- a/api/.ruby-version
+++ b/api/.ruby-version
@@ -1 +1 @@
-3.3.6
+3.4.7
diff --git a/api/Dockerfile b/api/Dockerfile
index cab40aff1..e83488b6f 100644
--- a/api/Dockerfile
+++ b/api/Dockerfile
@@ -1,5 +1,5 @@
 # syntax=docker/dockerfile:1
-FROM ruby:3.3.6
+FROM ruby:3.4.7
 RUN apt-get update -qq && apt-get -y install mariadb-client
 
 LABEL org.opencontainers.image.source=https://github.com/dodona-edu/dolos
diff --git a/api/Gemfile b/api/Gemfile
index 677622a22..c5f84e0ce 100644
--- a/api/Gemfile
+++ b/api/Gemfile
@@ -1,7 +1,7 @@
 source 'https://rubygems.org'
 git_source(:github) { |repo| "https://github.com/#{repo}.git" }
 
-ruby '3.3.6'
+ruby '3.4.7'
 
 # Bundle edge Rails instead: gem "rails", github: "rails/rails", branch: "main"
 gem 'rails', '~> 8.0.2'
@@ -15,6 +15,9 @@ gem 'puma', '~> 6.6'
 # Process ZIP archives
 gem 'rubyzip', '~> 2.4.1'
 
+# Parse CSV files
+gem 'csv', '~> 3.3', '>= 3.3.5'
+
 # Validate ActiveStorage attachments
 gem 'active_storage_validations', '~> 1.4'
 
diff --git a/api/Gemfile.lock b/api/Gemfile.lock
index 9577058ec..680a277fc 100644
--- a/api/Gemfile.lock
+++ b/api/Gemfile.lock
@@ -121,6 +121,7 @@ GEM
     concurrent-ruby (1.3.5)
     connection_pool (2.5.3)
     crass (1.0.6)
+    csv (3.3.5)
     daemons (1.4.1)
     date (3.4.1)
     debug (1.10.0)
@@ -327,6 +328,7 @@ DEPENDENCIES
   capistrano-rvm (~> 0.1.2)
   capistrano-yarn (~> 2.0.2)
   capistrano3-delayed-job (~> 1.7.6)
+  csv (~> 3.3, >= 3.3.5)
   debug
   delayed_job_active_record
   docker-api (~> 2.4.0)
@@ -347,7 +349,7 @@ DEPENDENCIES
   tzinfo-data
 
 RUBY VERSION
-   ruby 3.3.6p108
+   ruby 3.4.7p58
 
 BUNDLED WITH
    2.3.26
diff --git a/api/shell.nix b/api/shell.nix
index 4d68d1a12..2fdb00bad 100644
--- a/api/shell.nix
+++ b/api/shell.nix
@@ -2,7 +2,7 @@
 let
   dev = fetchTarball "https://github.com/numtide/devshell/archive/main.tar.gz";
   devshell = pkgs.devshell or (import dev { inherit system; });
-  ruby = pkgs.ruby_3_3;
+  ruby = pkgs.ruby_3_4;
 in
 devshell.mkShell {
   name = "Dolos API server";
@@ -19,7 +19,7 @@ devshell.mkShell {
     docker-compose
   ];
   language.ruby = {
-    package = (pkgs.lowPrio ruby);
+    package = ruby;
     nativeDeps = with pkgs; [ libmysqlclient libyaml ];
   };
   env = [
diff --git a/flake.lock b/flake.lock
index 252eb9886..5f337b7ef 100644
--- a/flake.lock
+++ b/flake.lock
@@ -7,11 +7,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1741473158,
-        "narHash": "sha256-kWNaq6wQUbUMlPgw8Y+9/9wP0F8SHkjy24/mN3UAppg=",
+        "lastModified": 1762521437,
+        "narHash": "sha256-RXN+lcx4DEn3ZS+LqEJSUu/HH+dwGvy0syN7hTo/Chg=",
         "owner": "numtide",
         "repo": "devshell",
-        "rev": "7c9e793ebe66bcba8292989a68c0419b737a22a0",
+        "rev": "07bacc9531f5f4df6657c0a02a806443685f384a",
         "type": "github"
       },
       "original": {
@@ -42,11 +42,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1744232761,
-        "narHash": "sha256-gbl9hE39nQRpZaLjhWKmEu5ejtQsgI5TWYrIVVJn30U=",
+        "lastModified": 1762977756,
+        "narHash": "sha256-4PqRErxfe+2toFJFgcRKZ0UI9NSIOJa+7RXVtBhy4KE=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "f675531bc7e6657c10a18b565cfebd8aa9e24c14",
+        "rev": "c5ae371f1a6a7fd27823bc500d9390b38c05fa55",
         "type": "github"
       },
       "original": {