Evgenii Uvarov

Life Pay / Fortis · Jul 2022 — present

Backend Developer · fintech for small and medium businesses in Russia: acquiring, Faster Payments (SBP), online cash registers

Fortis (MENA): merchant self-service · 2024 — present

• Self-service onboarding. A web portal where merchants register on their own, with registration steps orchestrated in Temporal. Wrote a substantial part of the workflows, with compensations and idempotent retries, and built a workflow registry page listing each workflow with its input and output JSON schemas.
• Authentication. Customized Keycloak: sign-in via token exchange, magic links, OTP and Sign in with Google, multi-layer brute-force protection. Built a Keycloak adapter service on FastAPI, and added API-key authorization for the Public API.
• Pricing and subscriptions. Worked on the pricing and subscriptions platform from the first AWS build to production in 2025; in 2026, built billing and add-ons. Designed and built a tariff/entitlements gateway for POS terminals from scratch, and validated it in shadow mode on live traffic: request mirroring, diffing against the BFF in Prometheus and Grafana, chaos testing for failure handling.
• Files and KYC. Built a file service from scratch and shipped it to production in 5 months: S3 storage, on-the-fly image resizing and transformations, background generation of variants, HEIC, WebP and PDF. Designed the KYC data model and built a document upload service.
• Merchant portal. Built a dashboard service for the merchant portal and a Zendesk ticket-enrichment service from scratch.
• HubSpot. Built merchant onboarding from a CRM deal and export of AI assistant and merchant portal usage metrics to HubSpot. For payment links from deals, extended the MyFatoorah adapter to support multiple accounts isolated by domain.
• Engineering foundations. With the team, rolled out linters, pre-commit, CODEOWNERS and SonarQube across roughly 15 projects, end-to-end tracing including Temporal workers, Sentry environments and Prometheus metrics for on-call. Built an Ansible-based Vault secrets configurator for disaster recovery. Wrote OpenAPI specs for some services, and covered API-first services with contract tests using Schemathesis.

AI in development · 2025 — present

• Built the Telegram interface for the merchant AI assistant (OIDC via Keycloak, Redis sessions, SSE streaming) and the data layer behind the LLM tool: it picks the data source and returns data in a single format. When the assistant moved to a separate perimeter with different data-residency requirements, connected new BFFs and adapted the infrastructure.
• Evaluated AI-based MR review using a test MR seeded with intentional bugs: compared qodo, kodus and my own prototype on local models. The paid agents missed bugs and gave inconsistent results across runs, so I proposed combining static analysis with parallel review of diff chunks.
• About a year of daily development with Claude Code, Cursor before that. Moved my setup to a provider-agnostic source: rules, skills, MCP and permissions live in one place (AGENTS.md), from which a tested generator builds configs for Claude Code and opencode. Measured token usage across 17 sessions and restructured my workflow around it: reading code in subagents, handoff hooks between sessions, and my own usage tracking.

Life Pay (Russia): online acquiring · 2022 — 2025

• For about 2.5 years, owned the payment links system and the SBP (Faster Payments System) Telegram bot as the original author: API v1 and v2, a client library, multi-tenancy, admin panel, metrics, support, and the track's quarterly roadmap.
• Built a service from scratch that relays card transactions into a unified merchant portal via Kafka: from message schemas to production, including a DLQ.
• Planned and ran the back-office migration from Python 2 and PHP to Python 3 and a current Django version, including moving database migrations from raw SQL to Alembic and then to Django migrations.
• In the payment gateway service, implemented the Yandex Split (BNPL) integration and, as groundwork for the MENA launch, the first MyFatoorah integration: refunds, webhook signature verification, multi-currency support, recurring payments.
• In the payment core, built two-stage payment handling (hold, confirm, void) and blocked repeat payment of an already-paid order; in the back office, built transaction status checks and status alignment on reconciliation mismatches.
• Diagnosed and fixed: 3DS flow hangs, false payment notifications, and duplicate orders caused by messenger link-preview bots.

Team and process

• Conducted technical interviews for hiring.
• Periodically took over part of my manager's duties: sprint planning, releases, running projects.

Stack: Python, FastAPI, Flask, Django, SQLAlchemy, Temporal, Keycloak, PostgreSQL, Redis, Kafka, S3, Kubernetes (EKS), GitLab CI, Vault, OpenTelemetry, Sentry, Prometheus, Grafana