Ruby On Rails Code Optimization Shortcuts

⚙️ Level Up Your Ruby on Rails Game: 10+ Code Optimization Shortcuts Only Pros Use 🚀💡

Ruby on Rails is elegant by default, but the real magic happens when you know its hidden shortcuts and smart optimizations. If you’re still writing verbose, repetitive code — you’re doing it wrong. 😅

Here’s your cheat sheet to code smarter, cleaner, and faster using these pro-level Rails tricks — optimized for performance, readability, and development speed. 💻⚡

🧠 1. select Only the Columns You Need (Avoid SELECT *)

User.select(:id, :email).where(active: true)

🔍 Why: Avoids loading unnecessary data into memory — faster DB queries and lighter memory footprint.

✅ Pro Tip: Combine with .find_each to process large records efficiently:

User.select(:id, :email).find_each(batch_size: 500) do |user|
  # process user
end

⚡ 2. pluck Over .map(&:field) = Ultra-Fast Fetch

User.pluck(:email)

🧠 Why: Direct SQL SELECT — skips ActiveRecord object creation = faster execution!

❌ Avoid this:

User.all.map(&:email) # Slow & memory heavy

✅ Pro Tip:

User.where(active: true).pluck(:id, :email)

🧙‍♂️ 3. find_by Over where(...).first

User.find_by(email: "demo@example.com")

🔥 Why: Less verbose, more intention-revealing, optimized under the hood for early exit.

🧩 4. Memoization Pattern for Heavy Methods

def user_profile
  @user_profile ||= fetch_profile_from_api
end

⛓️ Why: Avoids repeated expensive calls. Elegant state caching pattern for instance methods.

✅ Pro Tip: Use for:

• API responses
• DB-intensive lookups
• File reads

🧼 5. Service Objects + yield_self

class InvoiceGenerator
  def self.call(order)
    order.yield_self do |o|
      # process invoice
    end
  end
end

🛠 Why: Keeps business logic clean, separates concerns, and improves testability.

✅ Pro Tip: Chain-friendly and readable for complex service pipelines.

📊 6. scope for Reusable, Chainable Queries

scope :active, -> { where(active: true) }
scope :recent, -> { order(created_at: :desc) }

💎 Why: Clean and DRY code. Chaining becomes beautiful:

User.active.recent.limit(10)

🔐 7. before_save if: Condition for Lean Callbacks

before_save :normalize_email, if: -> { email_changed? }

def normalize_email
  self.email = email.strip.downcase
end

⚠️ Why: Avoid running unnecessary code — optimize only when needed.

✅ Pro Tip: Use conditional callbacks (if, unless) instead of burying checks inside methods.

🚀 8. update_columns vs update vs update_attribute

user.update_columns(views_count: user.views_count + 1)

⛔ update runs validations and callbacks. ✅ update_columns skips validations, callbacks — use only when safe.

📌 When to use:

• Updating counters/logs
• System-generated updates

🧬 9. JSON Column Access via store_accessor

store_accessor :preferences, :theme, :notifications_enabled

🎯 Why: Access JSON fields like normal attributes — reduces boilerplate!

user.theme # => "dark"
user.notifications_enabled = true

🌀 10. Rails Console Ninja Moves

app.get '/dashboard'
app.response.body

🐱‍👤 Why: Use the app object in console to simulate real HTTP requests.

✅ Pro Tip: Use .helpers, .url_helpers, and .reload! like a pro:

helpers.number_to_currency(12345.67)
Rails.application.routes.url_helpers.user_path(1)
reload!

🔄 Bonus: Optimize Seeds with find_or_create_by

User.find_or_create_by(email: 'admin@example.com') do |u|
  u.name = 'Admin'
  u.role = 'superadmin'
end

🔥 Why: Avoid duplicate records and make your seed idempotent (safe to run multiple times).

✨ Final Pro Tips

✅ Use .includes or .eager_load to prevent N+1 queries ✅ Prefer delegate for cleaner model relationships ✅ Cache partials or fragments with cache helper ✅ Use bullet gem in dev to catch performance issues ✅ Profile slow SQL queries using rails db:verbose and EXPLAIN

📌 Conclusion

You don’t need to write more code — you need to write optimized code. Rails gives you everything, but it’s up to you to use its power features wisely. ✨

These shortcuts aren’t just tricks — they’re a philosophy:

“Write less. Do more. Stay fast. Stay elegant.”