Backend Engineer

Building Systems That Handle Real Complexity.

I build production backend systems using NestJS, TypeScript, PostgreSQL, Kafka, and Redis.

From concurrency-safe enrollment to event-driven processing and AI media pipelines, I focus on solving real engineering problems.

NESTJS · TYPESCRIPT · KAFKA · POSTGRESQL · REDIS

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Addis Ababa, Ethiopia · Open to opportunities
MICROSERVICESEVENT-DRIVEN SYSTEMSDATABASE ENGINEERINGAI INTEGRATION
— ABOUT ME
Tamirat Fereja, Backend Systems Engineer

Backend systems that scale

Tamirat Fereja is a Backend Systems Engineer specializing in NestJS, TypeScript, microservices, Apache Kafka, PostgreSQL, Redis and distributed systems. He builds production-oriented backend architectures, event-driven services, scalable APIs and AI-enabled applications. His engineering work includes PostgreSQL transactional systems with pessimistic locking, hierarchical content management, AI transcription pipelines, and MinIO S3-compatible object storage.

Engineered distributed microservices with NestJS, TypeScript, and Apache Kafka for event-driven backend architectures

Designed transactional enrollment systems using PostgreSQL pessimistic locking and Redis caching with scan invalidation

Integrated AI transcription pipelines with faster-whisper and Google Gemini, processing audio at 95%+ accuracy

Architected hierarchical content systems managing 10,000+ learning objects with sub-50ms PostgreSQL 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
— ENGINEERING EXPERTISE

Technologies I use to build production systems

Backend engineering stack for scalable, distributed applications

Backend Engineering

NestJSNode.jsTypeScriptREST APIsTypeORMExpress.js

Distributed Systems

MicroservicesApache KafkaEvent-Driven ArchitectureEureka Service Discovery

Data Systems

PostgreSQLRedisTypeORMPessimistic LockingMaterialized Path Trees

Infrastructure

DockerDocker ComposeMinIO S3GitHub ActionsCloudinary

AI Integration

faster-whisperGoogle GeminiAI TranscriptionAI Quiz GenerationPython

Architecture Patterns

Service BoundariesAsync ProcessingTransactional ConsistencyAPI GatewayCaching

Languages

TypeScriptJavaScriptPythonSQL
— EXPERIENCE

Building distributed systems

Backend engineering work with measurable architectural impact

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 file service server 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
  • Created NestJS video streaming microservice supporting HTTP byte-range requests and adaptive chunking, boosting load performance.78% faster load
NestJSFastAPIPostgreSQLTypeORMRedisKafkaEurekaDockerMinIOPuppeteer
2026 – Present

Full-Stack Developer

Dental Clinic

Dental Management Platform

  • Built a full-stack dental practice management SPA with role-based access for admins, receptionists, doctors, accountants, and patients across patients, scheduling, treatments, and billing.5 roles
  • Implemented a seven-state appointment lifecycle with enforced transitions, conflict-aware availability checks, and a live daily timeline for clinic operations.7-state workflow
  • Designed an interactive FDI odontogram for permanent and primary dentition, including tooth validation and clinical treatment planning.FDI charting
  • Delivered invoicing, payment collection, and a finance analytics dashboard with ETB currency handling, outstanding balances, and collection-rate reporting.Finance suite
  • Integrated DHIS2 health-reporting and AfroMessage SMS workflows, covering indicator validation, report approval, submission history, and Unicode-aware SMS templates.DHIS2 & SMS
React 19TypeScriptViteTanStack QueryNestJSTailwind CSSDHIS2
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

Backend systems & case studies

Production-oriented backend architectures solving real engineering problems.

Distributed EdTech Platform with NestJS and Kafka

Distributed EdTech Platform with NestJS and Kafka

A distributed backend system built with NestJS microservices, Apache Kafka for event-driven communication, PostgreSQL for transactional data, and Redis for caching. The platform includes an API Gateway, authentication service, content service, cohort service, progress service, and assessment service communicating asynchronously through Kafka topics.

7+
services
10k+
dbObjects
Event-Driven
architecture
NestJSTypeScriptApache KafkaPostgreSQLRedisDockerMicroservices
Code
PostgreSQL Transactional Enrollment with Pessimistic Locking

PostgreSQL Transactional Enrollment with Pessimistic Locking

A cohort enrollment system using PostgreSQL pessimistic write-locking to eliminate seat allocation race conditions. Integrates Google Calendar OAuth2 for bidirectional sync and implements TypeORM event subscribers with debounced queues for differential progress updates.

Zero
raceCondition
90% less
writeLoad
OAuth2
sync
NestJSTypeORMPostgreSQLPessimistic LockingGoogle Calendar APIKafka
Code
Hierarchical Content Management with PostgreSQL

Hierarchical Content Management with PostgreSQL

A materialized path tree model managing 10,000+ learning objects with sub-50ms query times. Features Redis caching with scan invalidation and a reorder engine updating descendant nodes in a single raw SQL query, reducing database write load by 75%.

sub-50ms
queryTime
10k+ nodes
treeScale
75% less
dbWriteLoad
NestJSTypeORMPostgreSQLRedisMaterialized Path TreesKafka
Code
AI Transcription and Learning Workflows

AI Transcription and Learning Workflows

A FastAPI microservice integrating faster-whisper (int8 quantized CPU) with Google Speech Recognition fallback for Ethiopian languages. Automatically triggers adaptive model sizes based on resource monitoring. Includes AI quiz generation and automated certificate issuance via Puppeteer and MinIO S3.

95%+
accuracy
60% faster
latency
100%
automation
FastAPIPythonWhisperGeminiPuppeteerMinIO S3Kafka
Code

Other Notable Projects

NestJS MinIO S3 Object Storage

Cloud-native file storage microservice with MinIO S3-compatible object storage and stream management.

NestJSMinIOS3Docker
Code

NestJS Video Streaming Service

Adaptive video chunking and streaming microservice supporting HTTP byte-range requests.

NestJSNode.jsStreamingByte-Range
Code

PostgreSQL Multi-Database Backup Engine

Python utility for dynamic multi-database discovery, schema awareness, and safe restore operations.

PythonPostgreSQLpsycopg2DevOps
Code

BETE Real Estate Platform

MERN-based real estate platform with localized multilingual support for Amharic, Afaan Oromo, and Tigrinya.

ReactNode.jsMongoDBExpress
Code

Batch Image-to-PDF Pipeline

Multithreaded Python utility using concurrent futures for image scaling and automated PDF formatting.

PythonPillowConcurrencyPDF
Code

AI Image Generator

React and AI API text-to-image generator with modern dashboard interface.

ReactAI APITailwind CSS
CodeLive

QR Code Generator

Full-stack MERN QR code generator with custom styling and analytics support.

MERNCanvasQR Code
CodeLive

Amharic News Scraper

Python news scraping and NLP text analysis tool for Amharic media content.

PythonBeautifulSoupNLPScraping
Code
View All Projects on GitHub
— GET IN TOUCH

Let's build something amazing

Open for backend engineering opportunities, distributed systems consulting, and technical collaborations

Ready to collaborate?

Whether you need a distributed backend system, NestJS microservices, or event-driven architecture — let's talk.

Email

tamiratfereja1029@gmail.com

Location

Addis Ababa, Ethiopia

@TAMIRAT-FEREJA-TTamirat Fereja@Tamirat_NE

Designed & Built by Tamirat Fereja

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