Content Auto-Posting Scheduler from Website to Social Media

Implementing a Social Media Auto-Posting Scheduler

Scheduler — it's not just "queue task". It's content flow management tool: post queue for weeks ahead, visual calendar, frequency limits, priorities, pauses by schedule (night, weekends).

Data Model

CREATE TABLE scheduled_posts (
    id              SERIAL PRIMARY KEY,
    source_type     VARCHAR(50),        -- 'product', 'promotion', 'article', 'manual'
    source_id       INTEGER,
    channel         VARCHAR(30),        -- 'vk', 'telegram', 'instagram', 'ok'
    scheduled_at    TIMESTAMP NOT NULL,
    status          VARCHAR(20) DEFAULT 'pending',  -- pending|processing|sent|failed|cancelled
    attempts        SMALLINT DEFAULT 0,
    last_error      TEXT,
    external_post_id VARCHAR(100),      -- post ID on platform after publishing
    content         JSONB,              -- serialized content (text, media, links)
    created_at      TIMESTAMP DEFAULT NOW()
);

CREATE INDEX idx_scheduled_posts_fire ON scheduled_posts (scheduled_at, status)
    WHERE status = 'pending';

Task Dispatcher

Dispatcher runs every minute via cron (or as daemon with sleep-loop):

def dispatch_pending_posts():
    now = datetime.utcnow()
    posts = db.query("""
        SELECT * FROM scheduled_posts
        WHERE status = 'pending'
          AND scheduled_at <= %s
        ORDER BY scheduled_at ASC
        LIMIT 50
        FOR UPDATE SKIP LOCKED
    """, [now])

    for post in posts:
        db.execute("UPDATE scheduled_posts SET status='processing' WHERE id=%s", [post.id])
        enqueue_post_job(post)

FOR UPDATE SKIP LOCKED — protection from double processing with multiple workers.

Rate Limiting

Each platform has limits:

Before queuing dispatcher checks counters via Redis:

key = f"post_count:{channel}:{date.today().isoformat()}"
count = redis.incr(key)
redis.expire(key, 86400)

if count > DAILY_LIMITS[channel]:
    reschedule_to_tomorrow(post)
    return

Publishing Time Windows

Channel settings define when posting allowed:

{
  "vk": {
    "allowed_hours": [9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20],
    "allowed_days": [1, 2, 3, 4, 5, 6, 7],
    "min_interval_minutes": 30
  },
  "telegram": {
    "allowed_hours": [8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21],
    "allowed_days": [1, 2, 3, 4, 5, 6, 7],
    "min_interval_minutes": 15
  }
}

If post scheduled for night, dispatcher shifts it to nearest allowed window.

Smart Distribution

When smart_schedule option enabled, system doesn't put all posts at same time. Algorithm:

1. Takes all posts with pending status without specific time
2. Computes available slots in next 7 days accounting for already scheduled
3. Evenly distributes posts across slots with minimum interval

Relevant for online stores with hundreds of products — to avoid publishing all at once after catalog import.

Management Interface

In CMS — page "Post Queue" with:

• Table of scheduled posts with filters by channel, status, date
• Buttons "Publish Now", "Reschedule", "Cancel"
• Calendar view (month/week) with drag-and-drop slot moving
• History of sent posts with links to published posts

Implementation Timeline

Scheduler with basic rules and two channels — 6–8 business days. Smart distribution, calendar UI, rate limiting across all platforms — additional 3–5 days.