Time to First Byte (TTFB) Optimization

Optimizing TTFB (Time to First Byte)

TTFB — time from request sending to receiving first byte from server. Good value: ≤ 800 ms (Google considers up to 600 ms acceptable). TTFB directly affects LCP: impossible to have good LCP with poor TTFB.

What comprises TTFB

DNS → TCP → TLS → Request → Server processing → First byte of response

Typical breakdown:

• DNS lookup: 10–100 ms (solved via preconnect + CDN)
• TCP + TLS: 30–150 ms (solved via HTTP/2, CDN)
• Server processing: 50–3000+ ms (most manageable part)

Full Page Cache

Most effective method: cache ready HTML.

// spatie/laravel-responsecache or custom solution
// Middleware added for guest GET requests

class FullPageCache
{
    private const TTL = 300; // 5 minutes

    public function handle(Request $request, Closure $next): Response
    {
        if (!$this->isCacheable($request)) {
            return $next($request);
        }

        $key = $this->cacheKey($request);

        if (Cache::has($key)) {
            return response(Cache::get($key))
                ->header('X-Cache', 'HIT')
                ->header('Content-Type', 'text/html; charset=UTF-8');
        }

        $response = $next($request);

        if ($response->getStatusCode() === 200) {
            Cache::put($key, $response->getContent(), self::TTL);
        }

        return $response->header('X-Cache', 'MISS');
    }

    private function isCacheable(Request $request): bool
    {
        return $request->isMethod('GET')
            && !auth()->check()
            && !$request->hasCookie(session()->getName());
    }

    private function cacheKey(Request $request): string
    {
        return 'fpc:' . sha1($request->fullUrl());
    }
}

Nginx FastCGI Cache

Cache at nginx level — faster than PHP/Redis cache:

# nginx.conf
fastcgi_cache_path /var/cache/nginx/fcgi
    levels=1:2
    keys_zone=LARAVEL:10m
    inactive=60m
    max_size=1g;

fastcgi_cache_key "$scheme$request_method$host$request_uri";

server {
    location ~ \.php$ {
        fastcgi_cache LARAVEL;
        fastcgi_cache_valid 200 5m;
        fastcgi_cache_valid 404 1m;

        # Don't cache for authorized users
        fastcgi_cache_bypass $cookie_laravel_session $http_authorization;
        fastcgi_no_cache     $cookie_laravel_session $http_authorization;

        add_header X-Fastcgi-Cache $upstream_cache_status;
        fastcgi_pass unix:/run/php/php8.2-fpm.sock;
    }
}

Purge by tag (via nginx-cache-purge module):

curl -X PURGE https://example.ru/products/iphone-15-pro

Database query optimization

// Slow query: N+1 problem
$products = Product::all();
foreach ($products as $product) {
    echo $product->category->name; // N+1 queries to categories
}

// Fast: eager loading
$products = Product::with(['category', 'images', 'brand'])->get();

// Profiling slow queries
DB::listen(function ($query) {
    if ($query->time > 100) {
        Log::warning('Slow query', [
            'sql'  => $query->sql,
            'time' => $query->time,
        ]);
    }
});

Redis for data caching

// Cache heavy query results
$categories = Cache::remember('categories:tree', 3600, function () {
    return Category::with('children')
        ->whereNull('parent_id')
        ->orderBy('sort_order')
        ->get();
});

// Cache counters
$stats = Cache::remember('product:stats:' . $productId, 300, function () use ($productId) {
    return [
        'views'    => ProductView::where('product_id', $productId)->count(),
        'sales'    => OrderItem::where('product_id', $productId)->sum('quantity'),
        'wishlist' => WishlistItem::where('product_id', $productId)->count(),
    ];
});

DNS and network optimizations

<!-- Preconnect to critical resources -->
<link rel="preconnect" href="https://fonts.googleapis.com">
<link rel="preconnect" href="https://cdn.example.ru" crossorigin>
<link rel="dns-prefetch" href="https://analytics.google.com">

OPcache for PHP

; php.ini
opcache.enable=1
opcache.memory_consumption=256
opcache.max_accelerated_files=20000
opcache.validate_timestamps=0    ; 0 in production
opcache.jit=tracing
opcache.jit_buffer_size=64M

Target values by request type

Optimization time: 2–3 days for cache setup and query profiling.