Open to opportunities

Tamirat
Fereja

Backend Specialist & Microservices Architect building high-concurrency systems, distributed event pipelines, and scalable backend solutions

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Interconnected Services

10k+

DB Objects Managed

AI Pipelines Built

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— ABOUT ME

Engineering solutions that scale

I'm a backend specialist who designs and implements reliable, distributed microservices that process high-concurrency operations. From Google Calendar bidirectional synchronization and debounced subscriber queues reducing database writes by 90%, to adaptive local transcription pipelines securing 95%+ accuracy — I focus on architectural excellence, performance tuning, and direct business impact.

Engineered high-concurrency systems featuring row-level pessimistic locking and debounced queues

Architected modular NestJS and FastAPI microservices with Eureka and Kafka integrations

Integrated local ML pipelines (Whisper AI) with low-resource language fallbacks and Gemini NLP features

Designed high-performance database schema structures handling 10,000+ nodes under 50ms queries

const transcribe = async (audio) => {
                      const result = await whisper.process({
                        model: "large-v3",
                        language: "auto",
                        task: "transcribe"
                      });

                      return {
                        text: result.transcript,
                        accuracy: "95%+",
                        latency: "60% faster"
                      };
                    }

95%+

Transcription Accuracy

78%

Faster Load Times

— TECH STACK

Tools I use to build production systems

Battle-tested technologies for scalable applications

Programming Languages

TypeScriptJavaScriptPythonSQL (PostgreSQL, MongoDB)

Backend Frameworks

NestJSFastAPIExpress.jsNode.js

Databases & Caching

PostgreSQLRedisMongoDBTypeORMMongooseFirebase

Messaging & Events

Apache KafkaEvent-Driven ArchitectureRequest-Reply RPC

Cloud & DevOps

DockerDocker ComposeMinIO (S3)CloudinaryGitHub Actions

Architecture Patterns

MicroservicesEureka Service DiscoveryPessimistic LockingMaterialized Path Trees

AI & Media Systems

faster-whisperGoogle Gemini APIGoogle Speech APIPuppeteer PDF RenderHTTP Streaming

— EXPERIENCE

Building at scale

Real impact, measurable results

02/2025 – Present

Senior Backend Engineer

Oneness eLearning Platform

OnePlanet International School

Architected a concurrent seat enrollment and Google Calendar OAuth2 sync system using PostgreSQL pessimistic write-locking, eliminating seat allocation race conditions.Zero races
Designed a TypeORM event subscriber progress queue with a 100ms debounce pattern to execute differential updates, lowering database write load.90% write reduction
Engineered a course structuring service with a materialized path tree model, delivering sub-50ms query times across 10,000+ learning nodes.75% less DB load
Built a FastAPI media analysis service using faster-whisper (int8 quantized CPU) and Google Speech recognition fallback for Ethiopian languages.95%+ accuracy
Designed an automated certificate issuance pipeline using Puppeteer and Handlebars, uploading to MinIO S3 and queueing emails via Kafka.100% automated
Established Netflix Eureka service discovery, dynamic TCP client proxies, Redis caching with scan invalidation, and Kafka route auto-discovery.Microservice mesh
Developed cloud-native file storage microservice integrating NestJS and MinIO, optimizing large file uploads and stream management.60% cost savings
Created NestJS video streaming microservice supporting HTTP byte-range requests and adaptive chunking, boosting load performance.78% faster load

NestJSFastAPIPostgreSQLTypeORMRedisKafkaEurekaDockerMinIOPuppeteer

01/2023 – Present

Full-Stack Developer

BETE Real Estate Platform

Built a comprehensive MERN-based real estate platform supporting property sales and rentals.Full-stack MERN
Integrated localized multilingual support for Amharic, Afaan Oromo, and Tigrinya.3 languages
Implemented secure user authentication utilizing JWT and Google OAuth 2.0 with optimized image assets.Secure auth
Designed role-based admin dashboards and Google Maps geographic filtering, driving user engagement.RBAC & Maps

ReactNode.jsMongoDBExpressJWTCloudinaryGoogle Maps

2024 – Present

Full-Stack Developer

Digital Cafe Menu System

Developed a digital menu system with interactive shopping carts, order tracking, and QR code capabilities.QR integration
Integrated Chart.js dashboards providing real-time financial tracking and sales analysis for merchants.Interactive charts

ReactExpressNode.jsMongoDBChart.jsTailwind CSS

— FEATURED WORK

Production-grade systems

Not toy apps. Real products solving real problems at scale.

AI Media Transcription & Fallback Engine

A FastAPI Python microservice integrating faster-whisper and Google Speech Recognition fallback for low-resource Ethiopian languages. Automatically triggers adaptive model sizes based on psutil resource monitoring.

95%+

accuracy

60% reduction

latency

Dynamic CPU/GPU

scaling

FastAPIPythonWhisper AIGemini AIGoogle Speech APIpsutil

Code

Cohort Program & Google Calendar Sync Engine

A NestJS service managing cohort scheduling and student calendar synchronization. Integrates Google OAuth2 and push-notification webhooks for bidirectional updates, secured via PostgreSQL row-level locks.

sub-200ms

p90Load

Pessimistic Locks

concurrency

OAuth2 Sync

sync

NestJSTypeORMPostgreSQLGoogle Calendar APIEurekaKafka

Code

Hierarchical Curriculum Structuring Service

High-performance content hierarchy structuring service using a materialized path model. Features Redis caching with scan invalidation and a reorder engine updating descendant nodes in a single raw SQL query.

sub-50ms

queryTime

75% less

dbWriteLoad

10k+ nodes

treeScale

NestJSTypeORMPostgreSQLRedisKafkaEureka

Code

Student Progress & Learning Analytics Service

A NestJS tracker that computes time-weighted metrics and predicts course completions. Optimizes performance via a 100ms debounced event subscriber queue and runs an automated Puppeteer certificate renderer.

90% reduction

writeLoad

100% automated

certification

SQL Aggregated

analytics

NestJSTypeORMPostgreSQLPuppeteerHandlebarsKafkaMinIO S3

Code