I build real-time distributed systems. The one I lead moves 350,000 parcels a day.

Portrait of Lemuel Donto

Real-time. Distributed. In production. From architecture to the team that ships it.

© Lead Software Engineer

Lemuel Donto

We are made of star-stuff.Carl Sagan

01Who I am

About

Software Engineer and Dev Lead with 4+ years designing, building, and operating distributed microservices in production.

I take an idea and turn it into a product that runs — from the interface to the infrastructure, built to stay reliable once real users are on it.

Right now I’m building GLS’s connected-locker platform — I design and develop a large part of it. On the side, I launch my own products — nothing drives me more than turning an ambitious idea into something real.

4+
Years of experience
5
Engineers led
2
Ventures live (MVP)
2
Cloud platforms (AWS · Azure)
How I work

I own a product end to end — from architecture to production — and I stay accountable until it runs, at scale, for real users.

What I bring
01

Technical leadership

I support a 5-engineer team, own the architecture, and align API contracts across companies.

02

Distributed systems at scale

Real-time, event-driven platforms — Apache Kafka, WebSocket — engineered for production scale.

03

Founder’s mindset

I don’t just ship features — I architect and launch my own ventures end-to-end.

04

Reliability & ownership

Observability, infrastructure-as-code and CI/CD — I own what I run in production.

05

Quality-driven

BDD, end-to-end and integration testing across polyglot, multi-service environments.

Diplôme d’ingénieur — Komlan Lemuel Donto, École Polytechnique Universitaire, Université Côte d’Azur
Education

Engineering Degree (MSc level) in Computer Science — Diplôme d’Ingénieur

Polytech Nice Sophia · Université Côte d’Azur

2019 – 2022 · Sophia Antipolis, France

Languages
  • EweNative
  • FrenchBilingual
  • EnglishProfessional working
02Trajectory

Experience

Four years building and running distributed systems in production — for a European parcel network and for international air freight.

GLSCurrent
Oct 2025 – Present Toulouse, France

Lead Software Engineer (Dev Lead)

GLS · General Logistics Systems

GLS is one of Europe’s largest parcel networks. My team builds the platform that plugs third-party locker providers into its Out-of-Home delivery network — a polyglot, event-driven system running on AWS.

5 engineers led~350K parcels / dayEmail-campaign UI redesigned
What I did
  • Support a 5-engineer team building a real-time microservices platform (Go, AWS) that integrates third-party lockers from multiple providers into GLS’s Out-of-Home (OOH) network.
  • Co-design the service architecture and AWS infrastructure with GLS’s solution architect and tech lead, and serve as primary engineering contact for external locker providers, aligning API contracts across companies.
  • Build and maintain end-to-end and integration test suites in Java with Cucumber and Gherkin (BDD), validating behaviour across a polyglot, multi-service environment.
  • Own platform reliability and infrastructure — Grafana observability for service health and real-time event flows, AWS infrastructure as code with Terraform, and CI/CD build/test/deploy automation.
  • Owned GLS’s recipient-notification overhaul — migrated 2,000+ lines of legacy HTML email to MJML templating and redesigned the UI of its email campaigns into responsive, maintainable templates.
GoAWSMicroservicesReal-TimeTerraformGrafana
Air France
Oct 2022 – Aug 2025 Toulouse, France

Full-Stack Software Engineer

Air France · via ASTEK Technology

Air France Cargo moves freight that must clear customs in every country it touches. I built and maintained the microservices behind those declarations and their compliance checks.

~3 years on the platformRule-based alert engine shippedOn-prem → Azure migration
What I did
  • Built and maintained microservices for international customs freight declarations and compliance verification, handling complex business rules, error management, and XML (XFWB) message flows.
  • Implemented a rule-based alert engine analysing XML freight documents to flag cases for manual review, established traceability for automatic freight blockages, and helped migrate on-premises apps to Microsoft Azure.
JavaSpring BootMicroservicesAzureXML / XFWB
03Selected work

Projects

Founder at heart, engineer in execution. I start a lot — I only keep what reaches production. Here are two.

01Mar 2024 – Present

Asiganme

West-Africa e-commerce marketplace

The problem

E-commerce in West Africa is held back by two things: payments — most buyers use mobile money, not cards — and product search that doesn’t match how people actually shop.

Status

In active development · team of 3 · buyer app + seller & staff web apps

What I built
  • Building a microservices marketplace for West Africa (Spring Boot/Java, Flask/Python) across three clients — a React Native buyer app and React web apps for sellers and staff.
  • Built the AI layer end to end: natural-language product search and a conversational shopping assistant (Python AI services + Elasticsearch), automated moderation that flags non-compliant listings, and seasonal demand analysis that surfaces the right products and promos ahead of time.
  • Integrated mobile-money and card payments — Ecobank API for mobile money, PayPal for cards — matching how West-African buyers actually pay.
  • Own the DevOps and infrastructure: the platform runs fully on AWS (SNS, SQS, S3), containerized with Docker and Docker Compose, and provisioned as infrastructure-as-code with Terraform.
  • Built the CI/CD pipelines for automated build, test and deploy, backed by an end-to-end test suite in JUnit, Cucumber and Gherkin (BDD).
Spring BootFlask / PythonReact NativeReactElasticsearchAWS (SNS · SQS · S3)DockerTerraform
02Apr 2025 – Present

Fintech Lending App

Short-term lending — installment credit

The problem

Short-term credit is hard to access without a formal credit history — a lender needs another way to judge solvency, and a reliable way to verify who they are lending to.

Status

In active development · team of 3 · loans repaid over 3–4 monthly installments

What I built
  • Architected the short-term lending app as microservices (Spring Boot) — loans repaid over 3 to 4 monthly installments.
  • Wrote the credit-scoring algorithm that judges a borrower’s solvency when there is no formal credit history to rely on.
  • AI identity verification: biometric face and ID-document analysis (Smile ID) for a KYC we can actually trust.
  • AI income analysis: payslips and proof-of-income documents read and extracted automatically (AWS Textract), then fed into the scoring.
  • Integrated payments end to end — mobile money through the Ecobank API, cards through Stripe and PayPal — for paying the loan out and collecting each monthly installment.
  • Own the DevOps and infrastructure on AWS: containerized with Docker Compose, provisioned as infrastructure-as-code with Terraform.
Spring BootSmile ID (KYC)StripePayPalAWS TextractDocker ComposeTerraform
04The stack

Skills

The stack I design, build and operate with — day to day, in production.

Languages
  • Go
  • Java
  • JavaScript
  • TypeScript
  • Python
  • C
  • SQL
Backend & Architecture
  • Microservices
  • REST APIs
  • Event-Driven Architecture
  • Distributed Systems
  • Spring Boot
  • Spring Cloud
  • Spring Security
  • Node.js
  • Apache Kafka
  • WebSocket (STOMP)
Cloud
  • AWS
  • EC2
  • S3
  • ACM
  • VPC / VPN
  • Textract
  • Microsoft Azure
DevOps & IaC
  • Terraform
  • Infrastructure as Code
  • Docker
  • Kubernetes
  • GitLab CI
  • GitHub Actions
  • Bamboo
  • Bitbucket
Frontend
  • Angular
  • React
  • React Native
  • Ionic
  • HTML
  • CSS
  • MJML
Observability & Testing
  • Grafana
  • Monitoring & Alerting
  • Cucumber
  • Gherkin
  • BDD
  • JUnit
  • E2E & Integration
Databases
  • PostgreSQL
  • MySQL
  • MongoDB
  • Oracle
05Say hello

Contact

Let’s build something together.

Got a project or an idea you want to bring to life? The fastest way to reach me is email — I read every message.

Profiles
Based in

Toulouse, France

Open to projects — worldwide