Available for backend engineering roles and contracts

Aleksis Lesieur

Senior Backend Engineer with 8+ years of experience designing and scaling Python-based systems for SaaS and data-intensive platforms.

8+ Years

Python backend engineering experience

99.9% Uptime

Service reliability achieved at Tapestry

-58% Cost

Infrastructure savings from Heroku migration

+45% Throughput

Data ingestion improvement at Footy Labs

Professional Summary

Delivered measurable impact through backend optimization, infrastructure modernization, CI/CD acceleration, and enhanced production reliability.

Specialized in Django, FastAPI, data pipelines, scalable distributed architectures, and cloud-native deployments.

Core Technical Skills

Main technologies and tools used for modern web product delivery.

Backend Development

  • Python
  • FastAPI
  • Django
  • REST APIs
  • WebSockets
  • AsyncIO
  • Rust
  • Actix Web
  • Rocket
  • Tokio
  • Express.js
  • Typescript
  • Node.js

Databases and ORM

  • MongoDB
  • PostgreSQL
  • Firebase
  • Supabase
  • Redis
  • SQLAlchemy
  • Diesel
  • Prisma

Cloud and DevOps

  • AWS
  • Google Cloud
  • Docker
  • CI/CD
  • GitHub Actions

AI, Architecture, and Testing

  • PyTorch
  • OpenAI
  • RAG
  • LLM
  • Microservices
  • Distributed Systems
  • Prometheus
  • Grafana
  • Sentry
  • Pytest

Professional Experience

Roles and outcomes from backend, data, and platform engineering work.

10/2025 - Present

Software Engineer (Contractor), Footy Labs — Vilniaus, Lithuania

07/2024 - 09/2025

Software Developer (Contractor), Tapestry — New York, NY (Global Remote)

01/2023 - 06/2024

Frontend Developer (Full-time), Refooro — Vilniaus, Lithuania (Remote)

03/2020 - 08/2022

Backend Developer (Full-time), Foster Marketplace — Phoenix, Arizona (Global Remote)

08/2018 - 12/2019

Web Developer (Internship), Cingant — Stockholm, Sweden (Remote)

Projects and Portfolio

Selected platforms and websites built for active business use.

Python Backend

Footy Labs

Python + FastAPI + Data Pipeline + CI/CD + Google Cloud

Architected scalable Python ETL pipelines for structured sports data ingestion, processing large datasets including players, clubs, leagues, and agencies with normalized relational mapping.

Visit project

Rust Backend

Stakit

Rust + Actix Web + PostgreSQL + Docker + CI/CD + Twitter API

Developed Stakit Twitter Raid System Backend Development, a Rust-based backend service for managing Twitter raid events, integrating with the Twitter API to handle real-time data processing.

Visit project

Express.js Backend

Vrbs DAO Platform

Typescript + Express.js + PostgreSQL + Redis + CI/CD + AWS

Delivered a Typescript Backend system integrating with Auction Smart Contract, and DAO Proposals Management System, handling high-throughput transactions and ensuring data integrity with PostgreSQL.

Visit project

Prediction Market

FactCheck.fun Prediction Market

Typescript + Express.js + REST API + PostgreSQL + Docker + CI/CD

Shipped a backend system for a predicition market on EVM, interacting with prediction market samrt contract, handling user bets, and providing real-time updates on market outcomes.

Visit project

Python Backend

topchretien.com

Python + Django + REST API + JavaScript + CI/CD + Payment Gateway Integration + Security

Built a donation platform for a non-profit organization, integrating with payment gateways and providing a seamless user experience for donors.

Visit project

Rust Backend

Foster Marketplace

Rust + Rocket + PostgreSQL + Diesel + Tokio + Async

Orchestrated scalable Rust backend architecture integrating APIs and smart contracts, handling 10k+ monthly marketplace transactions with reduced latency and improved throughput.

Visit project

Frequently Asked Questions

Quick answers on process, technology, and support.

I work on API platforms, SaaS backends, data pipelines, real-time services, and system modernization projects. Most engagements focus on scale, reliability, and delivery speed.

Send a Message