# Leonid Filbert

Leonid Filbert is a remote worker on Himalayas, Senior Software Engineer / Full-Stack Engineer at Everlabs, based in Ukraine.

Source: https://himalayas.app/@leonidfilbert

```text
Senior Software Engineer at Everlabs who built Loyaltie's billing and payments systems.
```

| Detail | Value |
| --- | --- |
| Availability | Looking for a job |
| Location | Ukraine |
| Authorized to work in | Ukraine |
| Salary expectations | 60k+ USD |
| Job categories | Software Engineer, Full Stack Engineer, Ruby On Rails Developer |
| Skills | Ruby on Rails, Ruby, SaaS Backend Development, REST APIs, Payment Systems, Billing, Stripe, PayPal, Webhooks, Third Party Integrations, PostgreSQL, Database Schema Design, Database Migration, Database Indexing, Query Optimization |
| LinkedIn | https://linkedin.com/in/leonid-filbert |
| GitHub | https://github.com/LeonidFilbert |

## About

```text
At Everlabs, I owned billing and payments for Loyaltie, a SaaS subscription marketplace, and built its payment flows across a Rails API and Next.js frontend. I designed subscription and billing flows and built Stripe and PayPal webhook processing with idempotent handlers.

I also built a queryable store for provider events, reducing discrepancy investigations from hours to about ten minutes. I contributed to Loyaltie's AI-driven onboarding and natural-language search, and have worked on Rails APIs, integrations, and query optimization at ErgoServ, Upwork, and PixelGrow.
```

## Experience

### Senior Software Engineer / Full-Stack Engineer

Everlabs. Jul 2020 - Sep 2026

```text
Owned billing and payments for a SaaS subscription marketplace, integrating 14 external services. Built and maintained Stripe and PayPal webhook handling, PostgreSQL schema, and AWS infrastructure.
```

Skills: Ruby-on-Rails, React, Next.js, Stripe, PayPal, PostgreSQL, AWS, S3, Amazon-SQS, Docker, Kamal, GitLab-CI-CD, Elasticsearch, Sidekiq, RSpec

### Ruby on Rails Developer

ErgoServ. Sep 2019 - Jul 2020

```text
Backend engineer on Rails applications, focusing on APIs, third-party service integrations, and query optimization.
```

Skills: Ruby-on-Rails, APIs, SQL

### Ruby on Rails Developer

[Upwork](https://himalayas.app/companies/upwork). Dec 2018 - Sep 2019

```text
Independent Rails developer for long-term clients, handling backend features, direct client communication, and solo delivery.
```

Skills: Ruby-on-Rails, Backend-Development, Client-Communication

### Ruby on Rails Developer

PixelGrow. Feb 2018 - Dec 2018

```text
Worked on client projects with broad ownership, including backend APIs, optimization, and non-standard requirements.
```

Skills: Ruby-on-Rails, APIs, Optimization

## Tech stack

- Sidekiq
- Amazon S3
- PostgreSQL
- Ruby on Rails
- Next.js
- Redis
- React
- Ruby
- Amazon SQS
- Sinatra
- Stripe
- PayPal
- Elasticsearch
- TypeScript
- RSpec
- Docker
- Searchkick
- Marketo
- Kamal
- Claude Code
- AWS
- REST APIs

To contact Leonid, message them from this profile with a Himalayas employer account: [Hire on Himalayas](https://himalayas.app/hire).

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