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Aleksis Lesieur

Aleksis Lesieur

Senior Backend Engineer

Vilnius, Vilniaus, Lithuania
80
Profile Score

About

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

Skills & Expertise (34)

Python Expert
9.1/10
8
Years Exp
REST APIs Expert
8.9/10
8
Years Exp
FastAPI Advanced
8.5/10
2
Years Exp
AWS Advanced
8.3/10
5
Years Exp
Django Advanced
7.8/10
4
Years Exp
LLM Next.js TensorFlow Microservices Distributed Systems Event-Driven Systems Grafana Prometheus Sentry Pytest Unit Testing Integration Testing Typescript React RAG OpenAI PyTorch GitHub Actions CI/CD Docker Google Cloud Redis Supabase Firebase Postgresql MongoDb AsyncIO ETL WebSockets

Work Experience

Software Engineer

Footy Labs

Oct 2025 - Present

Architected scalable Python ETL pipelines for structured sports data ingestion, processing large datasets including players, clubs, leagues, and agencies with normalized relational mapping. Developed asynchronous FastAPI services handling 1,000+ concurrent requests with sub-250ms average response time. Reduced deployment time by over 40% through CI/CD automation on Google Cloud. Enforced schema validation and mechanized testing to improve data consistency and system reliability. Decreased API failure rate by 35% through schema enforcement, validation layers, and automated Pytest coverage. Consolidated data ingestion throughput by 45% by optimizing parsing logic and parallelizing scraping workflows.

Backend Developer

Foster Marketplace

Mar 2020 - Aug 2022

Orchestrated a scalable Python backend architecture integrating multiple APIs and smart contracts, reducing transaction processing latency by 35% and improving system throughput by 2x. Led RESTful backend services handling 10k+ monthly marketplace transactions with fault-tolerant transaction workflows. Improved backend processing efficiency by 25% through modular service architecture refactoring. Containerized services using Docker and applied Jenkins-based CI/CD pipelines for streamlined builds and deployments.

Software Developer

Tapestry

Jul 2024 - Sep 2025

Expanded and optimized backend services integrating PostgreSQL, Redis, and REST APIs to support high-throughput application workloads. Boosted backend throughput by 30% through query optimization and architecture refactoring. Migrated infrastructure from Heroku to containerized deployments, reducing operational costs by 58%. Lowered PostgreSQL query latency by 40% through indexing strategies and query plan optimization. Increased service uptime to 99.9% by deploying structured monitoring and alerting with Prometheus and Grafana.

Frontend Developer

Refooro

Jan 2023 - Jun 2024

Refactored the company's landing page, focusing on responsive layout, performance and usability. Revamped and integrated UI animations and interactive elements to enhance user experience and visual engagement. Refined frontend accessibility and usability standards across internal tools. Translated vehicle parts documentation and product content from English to French, enabling accurate localization and supporting international users. Accelerated product delivery by implementing frontend architecture improvements and multilingual support.

Web Developer

Cingant

Aug 2018 - Dec 2019

Integrated frontend applications with backend REST APIs, reducing data-fetch latency by 40% and improving page load performance across high-traffic user flows. Collaborated with backend developers to integrate frontend components with REST APIs using the Angular framework. Generated technical documentation and established API integration workflows with the game development team. Produced technical documentation and worked together with cross-functional teams to deliver production-ready features. Managed and resolved assigned development tasks through Jira, ensuring timely completion and adherence to project requirements.

Education

Bachelor of Computer Science - Vilnius Gediminas Technical University

- · Afghanistan

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Profile Score Breakdown

📷 Photo 10/10
📄 Resume 10/10
💼 Job Title 10/10
✍️ Bio 10/10
🛠️ Skills 20/20
🎓 Education 10/10
⏱️ Experience 5/15
💰 Rate 0/5
🏆 Certs 0/5
Verified 5/5
Total Score 80/100

Profile Overview

Member sinceFeb 2026

Skills (34)

Python REST APIs FastAPI AWS Django LLM Next.js TensorFlow Microservices Distributed Systems +24 more