I Built a Job Application Bot With Python, FastAPI, and GPT-4 — Here's the Architecture

Яуа — Thu, 16 Apr 2026 19:47:37 +0000

After getting laid off, I built a system to automate my job search. It ended with 12 interviews in 7 days. This post covers the technical architecture.

Stack

Python 3.11 — main language
aiogram 3— Telegram bot framework (async, excellent)
FastAPI — REST API for the web dashboard
OpenAI API (GPT-4)— resume tailoring
Playwright — browser automation for sites without APIs
reportlab — PDF generation
SQLite + aiosqlite — storage (simple, works fine at this scale)
systemd — process management on VPS

The Resume Tailoring Prompt

The core of the system is a single well-engineered prompt:

TAILORING_PROMPT = ("""
    You are an expert resume writer. Given a base resume and a job description:
    1. Identify the top 5-7 skills/requirements in the job description
    2. Rewrite the resume's experience bullets to use the same language and keywords
    3. Do NOT add experience that doesn't exist in the base resume
    4. Keep the same factual content — only rephrase and reorder
    5. Prioritize the most relevant experience first
    6. Output only the final resume text, no commentary

    Base Resume: {resume}
    Job Description: {job_description}
""")

The key constraint is 'do not add experience that doesn't exist.' This keeps it honest while dramatically improving keyword matching.

hh.ru API Integration

hh.ru (Russia's largest job board) has a solid REST API:

async def search_vacancies(query, area='1', per_page=20, salary_from=None):
    params = {
        "text": query,
        "area": area,
        "per_page": per_page,
        "order_by": "publication_time",
    }
    if salary_from:
        params["salary"] = salary_from
        params["only_with_salary"] = "true"
    async with aiohttp.ClientSession() as session:
        async with session.get("https://api.hh.ru/vacancies", params=params) as resp:
            data = await resp.json()
            return data.get("items", [])

Applying requires OAuth but the API is well-documented and the rate limits are reasonable.

PDF Generation

reportlab for clean single-page PDFs:

from reportlab.platypus import SimpleDocTemplate, Paragraph, Spacer

def generate_pdf(text, name, output_path):
    doc = SimpleDocTemplate(output_path)
    styles = getSampleStyleSheet()
    story = [Paragraph(name, styles['Title']), Spacer(1, 12)]
    for line in text.split('\n'):
        if line.strip():
            story.append(Paragraph(line, styles['Normal']))
    doc.build(story)

Health Monitoring

Every 5 minutes, a systemd timer runs a health check that verifies:

Both SQLite databases respond
FastAPI is up on port 8080
hh.ru API is reachable
Disk space > 1GB
All systemd services active

On failure: auto-restart attempt, then Telegram alert to admin.

What I Learned

Async everything — the bot handles concurrent users, aiohttp + aiosqlite are essential
Idempotency matters— track applied vacancies to avoid duplicates
Rate limit respect — hh.ru will block you if you hammer their API. 1-2 req/sec is safe.
Playwright is slow — use native APIs where possible, browser automation only as fallback

Try It

The bot is live at @topbestworkerbot. Web dashboard at resumeai.bot.

Questions about the implementation? Drop them in the comments.

DEV Community: Яуа

I Built a Job Application Bot With Python, FastAPI, and GPT-4 — Here's the Architecture

Stack