Stafnear

We're building a traffic arbitrage / performance-marketing platform and are now refining it beyond MVP. You'll work on the core backend: tracking and redirect services, billing logic, webhook integrations, and database evolution on a live system. Short engagement (several weeks), part-time, post-payment.

What you'll work on

• Server-side tracking / redirect services under load and latency SLA — 302 handling, GeoIP lookup, fingerprinting, event logging
• Webhook / postback integrations — signed webhooks (HMAC), idempotency, reliable event ingestion from an external partner (broker)
• Financial / billing logic — commission and payment calculation, monetary arithmetic with Decimal (never float), state machines (pending / approved / paid / hold), chargebacks / clawbacks, idempotent recalculation
• Database schema design and evolution with backward compatibility — migrations on a live system

• Application-level security — webhook signing, JWT / secrets management, no PII in logs

   

Must-have stack

• Python 3.11+ with async (async/await, asyncio)
• FastAPI, Pydantic
• PostgreSQL at an advanced level — JSONB, indexing, query optimization on large tables, writing migrations
• SQLAlchemy 2.x + Alembic (or equivalent ORM + migrations)
• Redis, Celery

Strong plus

• Domain experience in iGaming / forex / trading / affiliate / adtech / performance marketing - understanding of GGR, FTD, postbacks, click-tracking, sub-ID, RevShare / CPA / Hybrid
• Cloudflare API (zones, DNS, DNSSEC, SSL, proxy), or solid DNS/SSL knowledge and experience with infrastructure APIs
• Anti-fraud / rules engines — velocity checks, fingerprint deduplication, IP / ASN / GEO analysis
• Experience with nginx, PM2, S3-compatible storage

Requirements

• Level: Middle+
• English: not critical

Conditions

• Duration: several weeks
• Workload: part-time
• Payment format: post-payment