Ba1Kerrr · Backend Developer

Selected work

Projects

Products whose architecture and backend I've built.

SoulMates

In development

A dating platform I designed and built solo, from the database schema to CI/CD: ML-based matching, real-time chat, WebRTC calls, and a couples ecosystem (shared budget, timeline, challenges).

Repository Pattern architecture; the ML recommendation engine runs as an isolated FastAPI service.
Two-tier caching (in-memory + disk) and batched queries eliminated N+1 lookups in candidate recommendations.
A LightGBM ranking model (16 features, Jaccard similarity of interests), MMR diversification, and an ELO rating to solve cold start.
340 tests at 97% coverage: unit, rollback-isolated integration, E2E (Playwright), load testing (Locust); deployed via GitHub Actions.

FastAPIPostgreSQLRedisRabbitMQCeleryLightGBM

Repository

Service center platform

Production

Client-facing app and internal app for service center staff. Geo-search with timezone detection, order flows, an API-key system, and integration tests for 50+ routes.

PHPYii2MS SQLRedis

Internal project

All projects →

A bit about me

An engineering approach to backend

I design REST APIs following Clean Architecture, SOLID, and the Repository Pattern. I optimize performance, build async processing on queues, and cover logic with tests, from unit to E2E.

Full story →

~/daniil/soulmates

$pytest app/tests/ -v

collected 340 items

340 passed in 41.2s

coverage: 97%

Expertise

Technologies & practices

From architecture and databases to queues, testing, and DevOps.

Backend

PythonFastAPIPHPYii2REST APIJWT / OAuth2

Databases & queues

PostgreSQLMySQLMS SQLMongoDBRedisRabbitMQCeleryKafka

Architecture & practices

Clean ArchitectureSOLIDRepository PatternMicroservicesEvent-Driven

DevOps & tools

DockerDocker ComposeKubernetesNginxCI/CDGitHub ActionsSentry

Testing

PytestPHPUnitPlaywrightLocusthttpx.AsyncClient

Git & APIs

GitGitHubPostmanSwagger / OpenAPIWebSocketsgRPC

Backend developer
Python (FastAPI) · PHP (Yii2)