Walid Laggoune
Walid Laggoune
Senior Backend Engineer
Open to roles
📍 Hamburg, Germany
Based in Hamburg, Germany
SENIOR BACKEND ENGINEER

Designing and scaling production systems in Go, PHP, and Python for 6+ years. Specializing in distributed systems, event-driven architecture, and high-throughput data pipelines.

0 Years experience
0 Memory reduced
0 Throughput gain
0 Products indexed
01 / 04
Go & Distributed Systems

gRPC, event-driven pipelines, high-throughput TCP servers, and CQRS/DDD at production scale.

net/httpchigingRPCprotobufGORMsqlxpgxzaptestify
02 / 04
PHP - Laravel - Symfony

Battle-tested at scale with Laravel Queues, Doctrine ORM, PHP-Swoole coroutines, and DDD bounded contexts.

LaravelSymfonyDoctrine ORMPHP-SwooleLaravel HorizonLaravel OctaneLaravel Lighthouse
03 / 04
Python - FastAPI - AI/ML

Vector search, recommendation engines, ML pipelines, and async services with FastAPI and Qdrant.

FastAPIasyncioPydanticQdrantrembgCelery
04 / 04
AI / LLM Engineering

RAG pipelines, LLM-orchestrated agents, and Claude-assisted engineering workflows in production.

RAGLangGraphOpenAI APIClaudeQdrant
6 YEARS OF EXPERIENCE
Dec 2025 - Present
ABOUT YOU
Hamburg, DE
Senior Backend Engineer
Go - Laravel - PHP - Node.js/TypeScript - gRPC - AWS RDS/SQS/SNS/S3/EKS - Valkey - GitLab CI/CD - Datadog - Claude
  • Cut worker memory by ~50% and increased throughput ~5x by redesigning monolithic PHP workers into a split Go reader / PHP consumer architecture, removing blocking I/O from the critical path.
  • Reduced database contention on high-frequency merchant status updates by implementing a low-latency Valkey caching layer, decoupling hot-path reads from RDS.
  • Guaranteed at-least-once delivery for millions of daily product events by architecting a resilient AWS SNS/SQS pipeline as the primary driver for Laravel queues, with dead-letter queues and retry policies.
  • Modeled complex merchant and product domains using CQRS and DDD in a large-scale event-driven codebase processing data from global partners including Adidas, Otto, and Tradebyte.
  • Maintained a low memory footprint on large merchant catalog ingestion by engineering chunked S3-staged Laravel jobs and Go-based ingestion services for high-volume file processing.
  • Resolved six-figure financial exposure incidents by triaging and fixing critical merchant-facing bugs across event-driven pipelines under time pressure.
  • Contributed a Node.js/TypeScript ETL pipeline feeding the internal BI application, extracting and transforming merchant/product data for reporting.
  • Deploys and operates backend services on AWS EKS (Kubernetes), building on prior Kubernetes operations experience from Yassir.
  • Uses Claude daily as part of the core engineering workflow, for feature development, debugging, and documentation.
May 2025 - Nov 2025
CSA Research
Remote
Fullstack Developer
Go - Laravel - PHP - MariaDB - Redis - LangGraph - RAG
  • Delivered a Go-based AI chatbot backend integrating OpenAI APIs, enabling conversational features across enterprise-facing tools used by clients including Adobe, Dell, Mozilla, and XTM International.
  • Built and maintained a LangGraph-orchestrated RAG pipeline retrieving from thousands of internal CSA Research documents to ground chatbot answers in accurate source material.
  • Reduced 80% of legacy technical debt by modernizing and re-architecting enterprise backend systems, improving maintainability and deployment reliability for production workloads.
Oct 2024 - Apr 2025
Pulsetracker SaaS
Independent
Founder & Backend Developer
Laravel - PHP-Swoole - TCP/IP - WebSocket - Nginx - MariaDB - Redis - Stripe
  • Built a real-time SaaS from zero to production, handling 10,000 concurrent connections on a single node using PHP-Swoole with concurrent WebSocket, TCP, and UDP connections.
  • Sustained 60,000+ location writes per day against MariaDB by optimizing geo queries and schema indexing to keep p99 read latency under 30ms.
  • Achieved self-sustaining monetization by integrating Stripe subscriptions with tiered pricing covering geofencing, live tracking, and developer API access.
  • Received Innovation Award from phpclasses.org for real-time architecture design.
Apr 2020 - Aug 2024
Yassir
Algiers, DZ
Backend Developer & Team Lead
Go - TCP/IP - Symfony - Doctrine ORM - Laravel - PHP-Swoole - HAProxy - Nginx - MariaDB - Redis - Meilisearch - Kafka - Python - FastAPI - Qdrant - RAG - rembg - Node.js/TypeScript - AWS EC2/S3/ECR - Prometheus - Grafana - Docker Swarm - Kubernetes
  • Led 3-person backend team delivering REST and GraphQL (Laravel Lighthouse) APIs across 4 interconnected mobile apps (grocery, food delivery, merchant management, recipe reels), coordinating domain boundaries across Symfony and Laravel services.
  • Built and owned a high-performance Go TCP server processing 5,000,000+ delivery-driver location updates per day, plus thousands of other real-time events (stock availability, order notifications), forming the core of a dispatch pipeline through a Kafka cluster (set up and operated end-to-end: broker config, topic/partitioning design, consumer groups) and a matching algorithm to the driver's app.
  • Prevented race conditions in concurrent order acceptance, ensuring exactly one driver claims each order - matched to the nearest available driver using real-time location data.
  • Reduced product search latency to sub-50ms across 70,000+ SKUs by designing a Redis + Meilisearch search layer with query caching, replacing slow SQL full-text scans.
  • Increased concurrent user capacity 6x by replacing synchronous PHP-FPM with PHP-Swoole coroutines, enabling peak load without horizontal scaling.
  • Improved product discovery conversion by 30% by designing a personalized recommendation algorithm optimizing display rank across 70,000+ products using purchase history and catalog signals.
  • Surfaced ranking signals across 200+ store catalogs by engineering a top-selling product algorithm aggregating sales velocity and inventory data for marketplace dashboards.
  • Applied DDD to decompose a monolithic Q-commerce codebase into bounded contexts (catalog, ordering, fulfillment), reducing cross-team merge conflicts and enabling independent deployments.
  • Built and maintained Python FastAPI async REST APIs over ~3-4 years, including a Qdrant vector database-backed recipe recommendation service powering the recipe reels app, surfacing similar recipes based on users' liked reels.
  • Extended the recipe recommendation service into a RAG pipeline, retrieving similar recipes via Qdrant vector search and generating personalized descriptions with an LLM.
  • Automated product image background removal using rembg, integrated into the product-catalog pipeline to standardize listing images at scale.
  • Deployed and operated backend services on Kubernetes, managing rolling deployments, scaling, and incident troubleshooting alongside Docker Swarm-based workloads.
  • Built an internal Node.js/TypeScript admin/dashboard tool giving operations teams visibility and control over backend data and workflows.
Nov 2020 - Nov 2023
CELEC Club (USTHB)
Algiers, DZ
Head of Digital Dept & Backend Developer
Laravel - Lumen - PHP-Swoole - Python - Nginx - MySQL - Meilisearch
  • Automated applicant selection, cutting manual review time by 80% via a scoring algorithm ranking candidates against weighted criteria.
  • Shipped 5+ production APIs for event platforms and internal tools used by hundreds of university students.
  • Upskilled 50+ student developers through 8 free training sessions on Laravel, backend architecture, and database design.
ASK ME ANYTHING
TECHNICAL SKILLS
Go (Golang)90%
PHP - Laravel / Symfony95%
Python - FastAPI / asyncio70%
Distributed Systems / Architecture88%
Databases & Search85%
DevOps / Cloud (AWS, Docker, K8s)80%
AI / LLM Engineering (RAG, LangGraph)65%
Go Ecosystem
net/httpchiginfibergorilla/muxgRPCprotobufcobraviperzapzerologgo-redisGORMsqlxpgxtestifygomockgolangci-lintairdelve
PHP Ecosystem
LaravelSymfonyDoctrine ORMPHP-SwooleLaravel HorizonLaravel OctaneLaravel LighthouseLumenSlimLaravel QueuesLaravel Nova
Python Ecosystem
FastAPIasyncioPydanticUvicornrembgCelery
Node.js / TypeScript
ETL PipelinesBI ReportingAdmin Tooling
AI / LLM Engineering
RAGLangGraphOpenAI APIClaude
Databases & Search
MySQLPostgreSQLMariaDBMongoDBRedisValkeyMemcachedMeilisearchQdrantElasticsearch
Messaging & Queues
KafkaAWS SQS/SNSRabbitMQCeleryBeanstalkd
Cloud & DevOps
AWS EKSKubernetesAWS EC2AWS S3AWS ECRAWS ECSDockerDocker SwarmNginxHAProxyGitLab CI/CDDatadogGrafanaPrometheusElasticsearch
Architecture & API
CQRSDDDEvent-DrivenMicroservicesRESTGraphQLgRPCWebSocketTCP/UDPOAuth 2.0JWT
Spoken Languages
English - FluentFrench - B2German - A2
OPEN SOURCE
GET IN TOUCH
Location
Hamburg, Germany
LinkedIn
walid-laggoune